Tri Cruiser

Build the TriCruiser Recumbent Trike Another Atomic Zombie™ Extreme Machines Adventure

All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

1

TriCruiser Recumbent Trike

Table of Contents

Table of Contents Characteristics............................................................................................................. 3 Main Boom ................................................................................................................. 7 Rear Triangle............................................................................................................. 13 Homebuilt Seat.......................................................................................................... 24 Back Rest .................................................................................................................. 32 Adjustable Bottom Bracket....................................................................................... 35 Trim the Boom.......................................................................................................... 44 Head Tube ................................................................................................................. 45 Front Boom ............................................................................................................... 51 Truss Tubes ............................................................................................................... 61 Steering ..................................................................................................................... 63 Chain Management ................................................................................................... 83 Final Touches, Painting and Adjustments ................................................................ 95


2


Characteristics

Characteristics The TriCruiser recumbent trike is a great all-weather vehicle and very comfortable cruiser. Because the seat is higher than most recumbent trikes, visibility in traffic is good, placing you at eye level with most vehicles. The recumbent position allows for more efficient pedaling, making the TriCruiser a great winter vehicle for staying in shape all year ‘round. The weight distribution of the long wheelbase configuration places traction in the rear wheel, and the rear suspension absorbs bumps for a very smooth ride. The nice thing about this trike is that you can build it using standard bicycle components, with no need to source special front axles or create complex steering parts. There is a ton of room for your own modifications, so feel free to experiment once you have read though the entire plan. Welding Hazards

All welding processes produce fumes and gases to a greater or lesser extent. Galvanized steels produce added fumes from the vaporized zinc coating. Fumes from welding galvanized steel can contain zinc, iron and lead. Use precautions, including high-velocity circulating fans with filters, good ventilation, air respirators and fume-extraction systems.

Figure 1 – Finding a rear suspension triangle and spring All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

3


Characteristics

The TriCruiser project uses the entire unmodified stock rear triangle from a typical suspension mountain bicycle. As shown in Figure 1, you will need the complete rear triangle (black section), the suspension spring, and at least the part of the main frame that contains the tube connecting the rear triangle to the frame that allows it to pivot. The front part of the frame is not important, so it can be in any shape as long as the rear of the frame is perfectly functional. Since you can purchase an entire bicycle about $100 (and sometimes even less), you might consider purchasing a new bike for parts so you can be assured that your rear, wheel, brake parts and shifting hardware are all in perfect working order. If you decide to consult your scrap pile or the local dump for parts, ensure that the rear brakes are working, and that the rim is not damaged in any way.

Figure 2 – The pivot tube and hardware will be needed

The only part of the bicycle frame that you need in addition to the rear swingarm and possibly the front head tube is the small tube that carries the plastic plugs allowing the swingarm to pivot up and down. Not all suspension frames are the same, but you can easily figure out which parts you will need even if they do not look like the one shown in Figure 2.


4


Characteristics

Basically, you will be taking any parts needed to re-fasten the swingarm to the new frame tubing, so cut them from the srcinal mountain bike frame.

Figure 3 – Choosing 1.5 inch round or square tubing

The entire TriCruiser frame is made from 1.5 inch mild steel round or square tubing with a 1/16 inch wall thickness. This tubing can be ordered from most steel suppliers and is very easy to cut and weld. Steel suppliers like to rate tubing wall thickness using a gage number, so 1/16 wall tubing will be called 16 gage tubing, and although there is a slight difference between the two, your best bet is to tell them you want a length of 1.5 inch tubing with a wall thickness as close to .0625 inch (1/16) as you can get. If you are a heavy rider (over 250 pounds), then you should ask for the next size after that, which will likely be 14 gage tubing, or .078 inch wall tubing. Round tubing can also be found at most hardware stores that carry electrical conduit. Thin walled conduit (also called EMT) is perfect for this project, and is measured from the inside diameter, so it is slightly wider across the diameter than 1.5 inches. I will be using EMT to build the TriCruiser, but the plan is the same for round or square tubing. The main boom runs from the pivot point of the rear swing arm all the way to the front head tube. The main boom also carries the seat back, and also allows the sliding bottom bracket to adjust for just about any leg length. The overall length of the main boom is determined by the size of the tallest rider that will use the TriCruiser, so it All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

5


Characteristics

can be cut down to a maximum length based on rider height rather than having a longer frame than you really need.


6

TriCruiser Recumbent

Main Boom

Main Boom To start, cut a 6 foot length of the square or round tubing to become your main boom. Yes, 6 feet is more than you will ever need, and you will be cutting it down once the bottom bracket has been set up for your tallest rider. It's better to start with an extra long main boom, than end up an inch too short because you forgot to add the extra few inches added by the seat padding or something similar. Figure 3 shows a section of 1.5 inch square and round tubing for comparison.

Figure 4 – Making a fishmouth cut for the pivot tube

The suspension swing arm pivot tube that was cut from the mountain bike frame needs to be connected to the end of your main boom, so you will need to cut the appropriate "fishmouth" shape at one end of the tube as shown in Figure 5. A good way to do this is to use the pivot tube as a guide to mark the area to be ground as shown in Figure 4, this way you don't take out too much material. The goal here is to make a good joint that will have no gaps once the part is welded in place. Again, your swingarm parts may differ, but the idea is the same. Before welding, tap out the swingarm bearings, as they are likely just plastic plugs and would melt instantly during the welding process.


7


Main Boom

Figure 5 – Fishmouth cut for the pivot tube

Round tubing is always more difficult to cut into angles and to make fishmouth cuts on, so take your time and use a round hand file to make the final touches on the joint. The fishmouth is shown cut into the boom in Figure 5 after a bit of rough grinding and then cleaned up with a round file.

Figure 6 – Pivot tube tack welded to the main boom


8


Main Boom

Figure 6 shows the swingarm pivot tube tack welded to the main boom on all four corners. Once you have the part tack welded and it has been checked for alignment, you can continue welding the joint starting with the top and bottom and then the sides. To ensure that the tube is welded inline with the boom, place a straight edge across one end of the pivot tube and check it against the length of the boom.

Figure 7 – Checking the pivot tube alignment

The straight edge placed over the end of the pivot tube should line up perfectly parallel with the boom tubing as shown in Figure 7. If your pivot tube is not aligned properly, then your rear swingarm will lean to one side, causing your final bike to not track properly, so get this angle as close as possible. With a few good solid tack welds in place, you could even reinstall the rear triangle to visually check alignment before doing any more welding.


9


Main Boom

Figure 8 – Weld the top of the joint first

When welding a joint, the first weld will always be the one that introduces the most distortion due to the contraction of weld metal when the parts cool. To ensure side-to-side alignment, weld the top and bottom of the joint first as shown in Figure 8. This order of operations is very important when welding, and becomes second nature when you have been at this hobby for awhile.


10


Main Boom

Figure 9 – Pivot tube completely welded

The entire joint can be welded as shown in Figure 9 once the top and bottom of the joint has been completed. Once the parts have cooled, you can tap the plastic bearings back into the pivot tube, and then bolt the rear suspension triangle onto the main boom. The pivot tube may have been warped slightly due to heat distortion, so it may take a bit of effort to get the bearings to fit back into the tube. If distortion is extreme, you may need to work the tube back into shape using a large hammer; you know the routine!


11


Main Boom

Figure 10 – Pivot tube shown on a square tubing boom

The square tube version is shown in Figure 10 after completely welding the pivot tube to the boom. From here on, I will only be using round tubing, but the dimensions and steps are exactly the same.


12


Rear Triangle

Rear Triangle

Figure 11 – Install the rear triangle on the main boom

The rear triangle is bolted onto the pivot tube, completing a large chunk of the building process. As shown in Figure 11, the installed rear triangle can pivot up and down freely, and it should be inline with the rest of the boom when viewed along the length of the main boom. Currently, there is nothing to connect the suspension spring to, so the next tube to be installed will hold the suspension spring and create a seat back support.


13


Rear Triangle

Figure 12 – Checking the angle of the seat tube

The seat tube is a 16 inch length of tubing that will connect near the rear of the main boom in order to connect your suspension spring, as well as create a mounting place for your seat back. The actual placement of this tube on the boom will depend on the shape and style of your rear triangle, and the seat angle of 30 degrees can also be altered if you think that you want a more reclined or a more upright position. The 30 degree angle is great for most people, but it can certainly be altered if you know how it will affect the overall feel of your completed bike. Figure 12 shows the approximate position on the main boom where I will have to mount the seat tube to attach the suspension spring so that it is just less than parallel to the ground. Read ahead a little to see how the spring angle will affect the suspension system. The goal is to place the spring in the same position relative to the rear triangle and pivot point as it was on the srcinal bike before you chopped it all up.


14


Rear Triangle

Figure 13 – Testing the seat tube joint for gaps

The seat tube gap should be carefully ground out so that there is minimal gap as shown in Figure 13. The adjustable square shown in Figure 12 is set to the desired angle so that it can be used as an angle reference as you clean up the joint for welding. A few degrees out will not cause any noticeable difference, so military precision is not necessary.


15


Rear Triangle

Figure 14 – Determining suspension spring placement

The rear triangle will connect to the main boom tube so that the chain stays are parallel to the main boom tube. In other words, if the main tube is on the ground flat, the rear triangle should also be sitting flat on the ground. This is important so that the chain aligns properly without rubbing on the rear triangle tubing. A look ahead to Figure 23 shows how the chain stays on the rear triangle are in a straight line with the main boom tubing. The position of the suspension spring should match the srcinal position that it was in before you hacked up the bike for the rear triangle. If you do not have the srcinal frame, then it is not difficult to figure out the correct placement of the spring. As shown in Figure 14, the spring will work fine if it is parallel to the ground as the chain stays sit flat on the ground. A few degrees lower than parallel is actually optimal since the pivot point creates an arc around the point at which the spring is connected to the frame (shown in Figure 14). Again, this is not rocket science, nor is deadly accuracy important. If your spring is too high or low as compared to the arc, then your suspension will become too soft, but depending on your weight, this could become an advantage. Once you calculate the basic placement of the seat tube, draw a mark on the seat tube and frame where the parts must connect as shown in Figure 14. Remember to keep the angle of All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

16


Rear Triangle

your seat tube correct when doing this. A helper might be needed to hold the seat tube at the correct angle and position as you mark the three points.

Figure 15 – Tack weld the seat tube to the main boom

Place a few solid tack welds on the seat tube and main boom joint as shown in Figure 15 so you can re-check the seat angle before welding. Beside the seat angle, you also need to ensure that the seat tube is inline with the main boom when viewed from the end.


17


Rear Triangle

Figure 16 – Checking seat tube and main boom alignment

As viewed from either end, the seat tube and main boom should be perfectly inline. Also shown in Figure 16 is the rear triangle, which is also inline with the other frame tubing. If your seat tube leans, tap it into place with a hammer or break the tack welds and try again.


18


Rear Triangle

Figure 17 – Start welding on the top of the joint

The same order of welding operations will be done on this joint to ensure inline alignment. Start with the top of the joint as shown in Figure 17, and then complete the rear of the joint.

Figure 18 – Welding the sides of the joint All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

19


Rear Triangle

Once the top and bottom of the joint have been welded, check the inline alignment by looking down the length of the frame. If the seat tube seems to be leaning a bit to one side, then weld on the opposite side of the joint first, as the contraction may actually help to pull the parts into alignment. Both sides of the joint are to be fully welded as shown in Figure 18 to complete the joint.

Figure 19 – Cutting spring mounts from the frame

The suspension spring is held to the rear of the seat tube using a pair of 1/8 inch bits of flat bar, or you could simply slice them out of your donor mountain bike frame, keeping the srcinal drilled holes. As shown on Figure 19, the suspension mounting tabs can be cut from the donor frame, bypassing the need to drill the appropriate holes for the mounting bolt.


20


Rear Triangle

Figure 20 – Suspension mounting tabs and bolt

The suspension mounting tabs are shown in Figure 20, salvaged from what was left of the srcinal mountain bicycle frame. If you decide to use flat bar to make the tabs, then just make sure you make them both the same size and drill the appropriate hole in each for the suspension spring bolt.

Figure 21 – Lining up the suspension mounting tabs


21


Rear Triangle

The suspension mounting tabs should end up in the approximate place you srcinally marked as shown in Figure 21. The tabs should also be evenly placed in the center of the tube to ensure that all parts are inline.

Figure 22 – Tack welding the suspension springs

Since you have already calculated where your suspension spring needs to be mounted, it's just a matter of installing the tabs on the suspension spring, then using it as a guide to make the first few tack welds as shown in Figure 22. The spring can then be removed and the tabs completely welded to the rear of the seat tube.

Figure 23 – Rear suspension tabs installed All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

22


Rear Triangle

The rear triangle is shown installed on the frame in Figure 23 after welding the suspension spring tabs to the seat tube. Notice how the chain stays form a straight line with the main boom tube. This is important for chain alignment. It is now necessary to create your seat so that you can calculate how long the main boom needs to be in order to accommodate your tallest user. The boom is much too long right now, and there is no point in having an extra long frame since everything past the reach of the crank arm is wasted space. You don’t need to upholster your seat right away, but you will need to create the seat with the same padding thickness that you plan to use in the end.


23


Seat

Homebuilt Seat

Figure 24 – Making a wooden seat base

The seat base and seat back will be made by cutting some 3/4 inch plywood as shown in Figure 24. My seat base is 11 inches long and tapered so that the rear of the seat is 11 inches wide and the front of the seat is 8 inches wide. The seat back is 16 inches long to fit the seat tube length and also tapered from 11 inches at the bottom to 8 inches at the top. I also rounded off the front and back of the seat base and back so that the material wouldn't rip while stretched around the wood. The six 4 inch lengths of flat bar (or bent shelf brackets) are used to fasten the seat base and seat back together to become one solid piece. This construction is extremely strong, especially once mounted to the seat frame.


24


Seat

Figure 25 – Seat base fasteners

Figure 25 shows the six seat fasteners cut from the same 1 inch flat bar used to make the seat mounting tabs on the seat frame. Each fastener was placed in the vice and pounded until they were all at the same angle as the seat. You could also use shelf brackets by simply bending them to the correct angle, and they will already be drilled for woodscrews.


25


Seat

Figure 26 – Connecting the seat boards together

The seat base and back are held together by the fasteners as shown in Figure 26. The fasteners are so thin that they will not have any effect on the foam covering once it is glued into place. If your seat angle is not perfect, simply bend the two seat halves to the desired angle. Imagine the nice adjustable seat you could make by using a few hinges in place of the fasteners!


26


Seat

Figure 27 – Padding the seat

When choosing a seat padding material, avoid that typical yellowish sponge stuff that you find in seat cushions because it is way too soft to be of any use. It should be somewhat difficult to squash a thick piece of good seat foam to half its thickness using only two fingers, yet not be so stiff that it has no give at all. The 1.5 inch thick blue foam shown glued to the seat in Figure 27 is designed for wheelchair seats, and has the ability to conform to your body after a few minutes, yet retain its srcinal shape once you are off of the seat. A visit to an upholstery shop will likely yield you some decent leftover material for your small seat padding needs. To cut the foam, trace the seat onto the foam, rough cut it just outside the line with a razor knife, glue the foam to the wood with a spray adhesive, and then trace the perimeter with a sanding disc using the angle grinder. The result is a perfect fit every time.


27


Seat

Figure 28 – Covering the seat

The seat can be upholstered by simply stretching some vinyl over the material and stapling it to the back of the wood as shown in Figure 28. A fitted and sewn seat will always look better, but this easy method can be done in the garage in a few minutes and looks decent as well, although there will be a few wrinkles at the corners. Stretch the material as much as you can and empty the staple gun!

Figure 29 – Finding plastic to cover the seat back All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

28


Seat

The back of the seat does not look very professional with the bare wood strewn with hundreds of staples, so some type of cover will be needed. Some plastic or even sheet metal cut to fit the seat will hide the mess as shown in Figure 30, and an old plastic tub (Figure 29) can be cut to make a nice seat back cover.

Figure 30 – Completed seat

The seat back cover is shown covering the staples and wood in Figure 30, held in place by a bunch of thumb tacks. The simple wood and vinyl seat looks pretty good, considering how simple its construction is.

Figure 31 – Making seat mounting tabs


29


Seat

If you are using the simple wood construction seat presented here, then you will need four mounting tabs like the ones shown in Figure 31 in order to fasten the seat to the frame. These tabs are 2 inch long pieces of inch wide flatbar or sheet metal with appropriate woodscrew holes drilled at each end.

Figure 32 – Installing the seat mounting tabs

The seat mounting tabs are welded to the main boom and seat boom as shown in Figure 32 to support the seat in two places. Other than making sure that your seat sits straight on your frame, there is nothing else to worry about.


30


Seat

Figure 33 – Seat installed on the frame

The completed seat is shown securely held to the frame by the four woodscrews in Figure 33. Now, we need to make a back rest.


31


Back Rest

Back Rest

Figure 34 – Parts for a back rest

Depending on your height and seating design, you may find that a backrest adds more comfort to your ride, especially over long distances. Do not be tempted to install a head rest though, as it will greatly constrict your ability to look around and will also deliver every little bump or vibration right to your head. A simple back rest can be made using a bit of exercise machine foam, a few bits of broom handle (Figure 34), and one of the cut off fork legs from earlier in the build.


32


Back Rest

Figure 35 – Making a foam clamp

The round foam pad will be clamped to the fork leg by the bolt that runs inside each of the wooden segments as shown in Figure 35. A hole for the fork leg was also made in the center of the foam pad.

Figure 36 – Back rest completed


33


Back Rest

The back rest is shown in Figure 36 after tightening the long bolt that squeezes the two wooden sections against the fork dropout. The fork leg can now be welded to the top of your seat tube in whatever position feels most comfortable.

Figure 37 – Installing the back rest to the frame

A washer is tack welded to the open end of the seat tube to allow the back rest to be welded into position. To find the optimal position for the back rest, have a helper hold it in position as you sit and then take the angle with an adjustable square. With a little creativity, you could also make an adjustable back rest as well.

Figure 38 – Welding the back rest to the frame


34


Bottom Bracket

The back rest tube (fork leg) is shown completely welded to the open end of the seat tube in Figure 38.

Adjustable Bottom Bracket

Figure 39 – The adjustable bottom bracket

The TriCruiser includes an adjustable bottom bracket so that riders of varying leg lengths can setup the pedal-to-seat distance correctly. This easy-to-adjust system shown in Figure 39 is simple to construct and will make adjusting your pedal to seat distance very easy. Read ahead to see how the adjustable bottom bracket will function before you cut any tubing.


35


Bottom Bracket

Figure 40 – Making a bottom bracket carrier

Figure 40 shows a small length of square tube cut so that it will create a box around the main boom tubing. This is necessary because the adjustable bottom bracket needs a flat side to hold the clamps in place. Without this side wall, the bottom bracket would tilt from side-to-side as soon as you tried to pedal with any real energy, and this is actually a common complaint by owners of some manufactured recumbent bikes that use two telescopic round tubes to create the bottom bracket adjustment. This method is rock solid and will not have any slipping problems, no matter how much of a powerhouse you are. The side walls can be made of 1/16 inch square tube that fit snugly around the boom tubing as shown in Figure 40, or from two separate pieces of angle iron welded to the boom on each side. The actual length of the side walls depends on how much bottom bracket adjustment you need, as measured when you tested each rider. I made my side wall tube 6 inches long. It is best to create the bottom bracket part shown in the next few steps before welding the carrier onto the frame.


36


Bottom Bracket

Figure 41 – Making an adjustable bottom bracket

It would be very difficult to guess the exact placement of the bottom bracket for your inseam (leg length) without making a small error. A fixed bottom bracket also means that you can’t alter the seat, or adjust the TriCruiser for anyone except for yourself, so an adjustable bottom bracket is the only logical option. If you cut the bottom bracket from an old bicycle frame, and leave a 12 inch or longer section of the seat tube connected (for the front derailleur), you can create a very functional adjustable bottom bracket with nothing more than a pair of steel plates. The bottom bracket and included seat tube will be mounted to the main boom with a clamp arrangement that allows the assembly to be placed practically anywhere on the boom to allow riders of varying heights to ride the bike. The two plates shown in Figure 41, along with the bottom bracket and seat tube stub, will form the sides of the clamp that will hold the bottom bracket against the side walls of the main boom as they are forced together by two bolts.


37


Bottom Bracket

Cut two 3/16 inch thick pieces of plate or flat bar to make the parts as shown in Figure 79. The plates are as wide as the diameter of the bottom bracket (1.75 inches), and are 3.25 inches long.

Figure 42 – Making bottom bracket clamping plates

Trace around the bottom bracket shell to draw a line on the two plates from corner-tocorner. The marker line should meet the corners of the plate to ensure that you don't cut out too much off of the plate when grinding out the rounded area. If you take too much metal away from the plate, there will not be enough room between the bottom bracket and the clamping bolts for the main boom. When grinding out the traced circular area for the bottom bracket as shown in Figure 42, place both plates in the vice so they can be done at the same time; this will ensure that both plates are exactly the same size. Try to make the gap as small as possible around the bottom bracket shell so that there is less distortion as the plates are welded. If the bottom bracket becomes overly distorted, it will be a serious challenge trying to screw the hardware back into the bottom brackets without stripping the threads.


38


Bottom Bracket

Figure 43 – Aligning the bottom bracket plates

To align the bottom bracket plates, clamp them to a piece of tubing that is the same width as the carrier tubing to ensure that they are both lined up parallel to each other. Figure 43 shows the two plates clamped to a bit of the tubing used to make the carrier part shown in Figure 40.

Figure 44 – Setting up the derailleur tube angle All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

39


Bottom Bracket

The derailleur tube will form a 56 degree angle with the main boom tubing as shown in Figure 44, so an adjustable square is used to hold it into position while tack welding the plates to the bottom bracket. This angle does not have to be perfect; just try to get it close.

Figure 45 – Tack welding the bottom bracket to the plates

The bottom bracket is shown tack welded to each corner of the plates while they are held in place by the clamp. Also notice in Figure 45 that the flat bottom bracket cup (the one with left hand threads) goes on the right side of the frame as it is the side that carries the chain ring. As a general rule, I never remove the right side cup, and it helps to leave it in while welding to avoid deforming the bottom bracket.


40


Bottom Bracket

Figure 46 – Marking a line to drill the bolt holes

Two 3/8 inch bolts will squeeze the bottom bracket plates against the flat sides of the carrier tubing as shown in Figure 46. To calculate where to drill the holes, place the bottom bracket onto a piece of tube (or the frame) and draw a line to show where the tubing will be so that you can drill the holes below this line. If you don’t drill below this line, the bolts will strike the frame tubing.

Figure 47 – Bolt holes drilled


41


Bottom Bracket

The completed adjustable bottom bracket assembly is shown in Figure 47 after drilling the four bolt holes. If your bolt holes do not line up properly, run the drill bit through each pair to fix the holes.

Figure 48 – Capping the open end of the tube

The derailleur tube has an open end that needs to be capped off to keep out moisture and dirt. A washer can become a top cap by welding it in place and then filling the hole with weld metal. As shown in Figure 48, a little work with the flap disc can make the tubing cap blend right into the end of the tube.


42


Bottom Bracket

Figure 49 – Installing the carrier tube or plates

The carrier tube that you made from the square tubing or angle iron pieces will be welded to the frame as shown in Figure 49 so that the bottom bracket can move into whatever position necessary to accommodate all of the riders. Since this bike was mainly for me, I made a very short carrier tube so that I could simply fine tune the position of the bottom bracket if necessary. Your carrier tube may be a lot longer than the one shown in Figure 49 depending on the difference between your tallest and shortest pilot. You will have to calculate the best place for the carrier tube by having the tallest and shortest riders sit in the seat and pedal the cranks. This is also how you determine the extra length that will be trimmed from the main boom as shown in the next few steps.


43


Trim the Boom

Trim the Boom

Figure 50 – Determining the boom trimming point

Have your tallest pilot sit back into the seat (wearing shoes) and install the bottom bracket so that the pedals are at the correct distance. Mark a point on the boom where his or her foot reaches the furthest. You can trim the main boom 6 inches ahead of the line you made in the last step. In Figure 50, the point marked (1) was where my foot reached, so I cut the boom off 6 inches ahead of that line. In the photo, the tape measure actually shows 9 inches, but that is because I decided to add a little extra room just in case someone taller than myself wanted to try the trike. Once you have determined the placement for the carrier tube, you can weld it to the frame as shown earlier in Figure 39.


44


Head Tube

Head Tube

Figure 51 – A front fork and matching head tube

The TriCruiser has three front head tubes! The middle head tube links the steering system to the pilot, and the other two carry the front forks. Any front fork with matching head tube like the one shown in Figure 51 will work for the center head tube. Size and shape are of no concern as long as all the parts work together. The fork legs will also be trimmed, so don’t worry if they are not in great shape.


45


Head Tube

Figure 52 – Testing the front fork hardware

When the fork hardware is completely put together as shown in Figure 52, you should be able to hold the head tube and give the forks a spin without any friction holding them back. If the forks feel stiff, then the bearings are likely either the wrong size or installed upside down. Taking the forks and head tube from the same bicycle is always a good idea.


46


Head Tube

Figure 53 – Head tube cleaned up

Take your angle grinder and remove any leftover tubing from the head tube. By first using a rough grinding disc followed by a sanding disc (flap disc), the head tube can be made to look almost like new as shown in Figure 53.

Figure 54 – Setting up the head tube angle


47


Head Tube

All three of the head tubes on the TriCruiser will have an angle of 68 to 70 degrees as measured from the ground (see Figure 55), which will give a predictable and responsive steering system. The front of the boom tube will need to have the proper fishmouth cut made to achieve the required head tube angle, and the best way to do this is to set up the bike as shown in Figure 54 with the rear wheel installed as well as one of your front wheels (whatever size you intend to use). As shown in Figure 54, I am setting up the angle using a 20 inch wheel, although I eventually decided to use two 24 inch front wheels instead. Both tires should also be inflated or both removed.

Figure 55 – Checking the 70 degree head tube angle

An adjustable square with a long straight edge taped to it makes a good guide when working out the fishmouth cut that will hold the head tube at the correct angle. The head tube angle is now close to 70 degrees as shown in Figure 55, so a tack weld can be made on the top and bottom of the joint to hold it in place. It is best to make the tack welds while the bike is propped up like this so you can visually inspect both the head tube angle as well as the alignment as viewed form the end of the frame.


48


Head Tube

Figure 56 – Tack welding the head tube

Once you have achieved the proper head tube angle (close to 70 degrees) and have inspected the frame to ensure that both wheels line up, add a few good tack welds to the head tube as shown in Figure 56 while the bike is still in place. With three or four tack welds holding the head tube in place, you can safely remove the forks and bring the frame to your workbench for welding.


49


Head Tube

Figure 57 – Weld the top and bottom of the joint first

Using the usual order of operations, the top and bottom of the joint are welded first as shown in Figure 57 in order to reduce side-to-side distortions. Leaving the cups installed in the head tube also helps prevent the tube from warping due to the contraction of the weld metal.

Figure 58 – Head tube joint completely welded


50


Front Boom

The sides of the joint are welded after the top and bottom as shown in Figure 58, completing the head tube joint. This is a critical weld, so make sure it is done properly and with good penetration.

Front Boom

Figure 59 – Making the front boom

The front boom tube forms a T shape with the main boom, creating a trike that has two front ends. This tube is made from the same type of tubing used to make the main boom and will determine the track (width) of your trike. Since the TriCruiser is not designed to be a high speed vehicle, you can keep the track fairly narrow, which makes it easy to get it through a standard doorway. Cut this tube to a length of 26 inches, which will result in a track width of about 28 inches once the front wheels are installed. Feel free to make your trike wider if you want more stability on really uneven terrain, but be aware that the wider you make your vehicle, the more road space you will require. Also, if you make your trike too narrow, you will have to do a lot more leaning around corners at any speed.


51


Front Boom

Figure 60 – Cutting the boom for the head tubes

There are no complex angles to deal with here as the goal is to install both head tubes at each end of the boom so they are perfectly parallel with each other. Draw a line down the center of the boom tube with a straight edge, and then transfer the line to the other side so you have a guide when roughing out the rounded fishmouth cuts needed to form a joint between the boom tubing and the head tubes. Figure 60 shows the fishmouth cuts made that will allow the head tubes to be welded to the boom tube.


52


Front Boom

Figure 61 – Tack weld the head tube to the boom tube

Just like you did for the center head tube on the end of the main boom, tack weld the two front boom head tubes as shown in Figure 61 so that they are centered and at 90 degrees to the boom tubing. By installing the head tube cups, you can place the assembly on a flat surface to ensure that both head tubes are inline with each other. Use a 90 degree square to check the angle between the head tube and the boom tubing.


53


Front Boom

Figure 62 – Head tube welded all the w ay around

Once you have a few tack welds holding each head tube at 90 degrees to the boom and have checked to ensure that both head tubes are parallel to each other, finish the welding around the entire joint as shown in Figure 62.

Figure 63 – Two equal sized front forks and wheels


54


Front Boom

The TriCruiser can be built with just about any size of front wheel you like, although it is best to use the same size wheel you used earlier when holding up the middle head tube for alignment. I decided to switch from a 20 inch front wheel to a 24 inch set, as I had a nice matched pair lying around the garage. As shown in Figure 63, both forks and wheels should be as similar as possible, to keep your trike steering properly.

Figure 64 – Checking the fork heights

You can get away with different style forks as long as the distance form the bearing races to the dropouts is the same for both. As shown in Figure 64, a straight edge placed along the bearing races can make a simple guide in order to ensure the forks are of equal length. The tops of the threaded stems can be cut a little to make them match as well.


55


Front Boom

Figure 65 – Trimming one head tube to match the other

The two head tubes that you will be welding to each end of the front boom must also match, so cut the longer one down to match the shorter one if necessary. Using the short one as a guide to draw the line makes this job easy (Figure 65).

Figure 66 – Checking the fork hardware

There are a lot of bearings and rings on the TriCruiser considering that there are four head tubes! It is best to keep the two front wheel sets as matched as possible, since you want the


56


Front Boom

trike to be exactly the same on each side. Figure 66 shows two identical head tube hardware sets after scrounging around in the scrap pile for some time.

Figure 67 – Two identical front forks and all hardware

The two front forks and head tubes are shown in Figure 67 after trimming the longer head tube and matching the entire fork bearing hardware before the welding was completed.

Figure 68 – Checking the forks with the front boom

One last check of your front boom assembly should be made as shown in Figure 68 so you can be sure that both forks are a very close match and that the head tubes are inline with each other. If you stand up the assembly as shown in Figure 68, the top of the boom should be parallel to All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

57


Front Boom

the ground. Looking from one end, both forks should appear to line up with one another as well.

Figure 69 – An alignment check with the two front wheels

With the two front wheels installed, the front assembly should pass all visual alignment check as well. If one wheel seems to be closer or further back than the other one then either your head tubes are not welded on correctly, or one of your forks does not match the other. Some slight difference is acceptable, but it should not look obvious.

Figure 70 – Marking the center of the front boom


58


Front Boom

The front boom will join with the middle head tube so that it forms a 90 degree angle with the main boom and puts all three head tubes at exactly the same angle. It would have been a really difficult task to cut the front boom in half and then attempt to weld each half back onto the frame, so instead, a fishmouth will be made in the center of the boom, allowing it to simply join to the middle head tube. Mark a line in the center of the boom as shown in Figure 70 so you can start rough grinding out the area to make a joint with the middle head tube.

Figure 71 – Fishmouth cut made to half the tube depth

The fishmouth cut will be made about as deep as half the tube diameter as shown in Figure 71. Work out a little material at a time with your grinder and then test fit the tube against the middle head tube to see how well the joint fits.


59


Front Boom

Figure 72 – Tack weld the front boom in place

Once you have a good fishmouth joint that conforms to the middle head tube, place the assembly in place and make a solid tack weld on the top of the joint as shown in Figure 72. You have to check the alignment between the two boom tubes (90 degrees), as well as make sure that the three wheels will stand up straight with one another (shown next).

Figure 73 – Checking the alignment of the wheels


60


Truss Tubes

Once you have the front boom solidly tack welded to the middle head tube, install all three wheels and check the alignment from the front of the trike as shown in Figure 73. You might have to bang the assembly with a mallet in order to get the two angles correct. The three wheels need to be inline with each other and the two booms need to form a 90 degree angle. Once you have the alignment the way you want, add a few more tack welds to the joint so you can handle the frame. No more welding will be done until the truss tubes (shown next) are installed.

Truss Tubes

Figure 74 – Boom truss tubing

To add strength to the front boom and make it easier to weld without an alignment error, two small truss tubes are added to form a triangle between the front boom and main boom tubing as shown in Figure 75. These tubes can be any scrap 6-8 inch long tubes with a diameter of ½ inch or larger. Hacked up seat stays or chopped fork legs would even work. Figure 74 shows a pair of half inch diameter hollow truss tubes cut to a length of about 8 inched and then cut at 45 degrees at each end.


61


Truss Tubes

Figure 75 – Installing the truss tubes

The truss tubes are installed at 45 degrees between the front and main boom tubes as shown in Figure 75. There is nothing critical here, but do make sure that the truss tubes will not interfere with your crank arms if you have made them longer than 8 inches. Once you have the two truss tubes fully welded, you can the completed the front boom joint as it will no longer distort your alignment as you weld all the war around the joint.


62


Steering

Steering

Figure 76 – Making the five steering control arms

Although the TriCruiser steering system does need a fair number of small parts, none of them are difficult to make. Some 1 inch wide flatbar or sheet metal is all you need. The parts shown above are made from some 1/8 inch thick flatbar and sheet metal and are based on the drawing shown next.


63


Steering

Drawing 1 – Dimensions for the five steering control arms

The holes are drilled to fit whatever size bolt you need for your ball joints and they are made so that there is about 3/8 of material between the end of the part and the edge of the hole. The larger control arm with the two holes is drilled so that the ball joints are as close together as they can be without rubbing. Again, nothing is absolutely critical, so don’t worry about military precision here. Just try to come close and make the four smaller control arms the same size.


64


Steering

Figure 77 – The master control arm installed

The larger control arm (master) is installed on the lower edge of the center steering fork stem as shown in Figure 77. Weld all the way around the joint to ensure that this part can take any steering stresses you might put on it.

Figure 78 – Adding the smaller control arm


65


Steering

One of the four smaller control arms will also be welded to the steering fork stem as shown in Figure 78. This control arm is welded above the master control arm, as close to the top of the bearing race as you can get without welding over the part of the stem that seats the race. This control arm is also pointing to the right of the master control arm as the part is held in the position shown in Figure 78. A look ahead at Figure 97 will show how these parts must work together, placing the control rod on the left side of the frame. Also, the bearing race is tapped off of the stem while you weld, so you can weld both sides of the joint without damaging the race.

Figure 79 – Installing the front fork control arms

The last two control arms will be installed on the front forks as shown in Figure 79. Do you notice how each control arm is on a slight angle towards the other one? This angle is about 10 degrees and it creates something known as Ackerman steering, which in simplified terms means that your wheels will not scrub the ground when you are making tight turns. Since the inner wheel on a turn travels less distance than the outer wheel, the inner wheel must also turn at a sharper angle. Although this can be a complex thing to engineer, the good news is that the angles shown in Drawing 2 will take care of this for you.


66


Steering

Drawing 2 – The simple Ackerman calculation

The simple explanation of how Ackerman steering angles are derived can be seen in Drawing 2. Basically, the front control arms point towards the rear wheel axle. Because of the long wheelbase, these angles are less critical, and even if you come close, your steering will work fine and produce minimal wheel scrub in tight corners.

Figure 80 – Parts for the under seat steering


67


Steering

Since the TriCruiser has under seat steering, you will need some way to mount the handlebars under the seat and transfer the steering movements to the front steering system. We will solve this problem by installing a set of handlebars under the seat using a small head tube, a standard gooseneck and a rod and some ball joints. Many USS (under seat steering) recumbent bikes use a simple bolt and brass bushing to hold the handlebars under the seat, and although this does indeed work, it is a cheap workaround that yields a flimsy connection prone to having slop and excessive play. A fork stem and head tube are not only designed to do this job perfectly already, but they will also allow you to use a standard bicycle gooseneck and build a steering system that is perfectly fluid, and will have absolutely no friction or slop whatsoever. To make your steering system, you will need a head tube and matching fork stem of any size. Figure 80 shows the head tube and a pair of badly damaged forks that I chose to make my steering system from. Only the legs of the forks were bent, and since they are not used, I found a good use for an otherwise scrap parts. The length of the fork stem and head tube are of no concern since they will be shortened in the next few steps. One thing to note. You want to make sure that the bearing races, head tube cups and bearings do work together properly because there are several sizes used. Put all the hardware together as a test. The fork stem should turn with almost no friction, even when all of the hardware is screwed on tight.


68


Steering

Figure 81 – Remove the fork legs

Start by cutting the fork legs away from the stem, and then grind off any excess material from both the fork crown and the head tube. What you should be left with will look like what I have shown in Figure 81. Before cutting the fork legs, remove the bearing race from the fork stem by tapping it off using a chipping hammer or chisel. This will ensure that it is not damaged by the grinder wheel when cutting the legs. It should be re-installed once the fork stem is cut and ground clean.


69


Steering

Figure 82 - Head tube and fork stem shortening

Your fork stem and head tube are likely too long for use in the under seat steering system, so they need to go through a simple shrinking procedure first. As shown in Figure 82, the head tube is first cut down to a length of 2.5 inches (not including head tube cups), and then a section of the fork stem is cut out using a tubing or pipe cutter. You must first cut the head tube to calculate how much to remove from the center of the fork stem so that the final stem will have room for all the hardware once it is installed into the head tube with all the hardware. I did this by cutting the head tube down to two inches and then I installed the bearing cups, crown side bearing and fork stem into the head tube. From there, you can simply mark a line somewhere on the fork thread that represents the maximum length you will need to install the top fork hardware. Now, you can calculate how much to remove from the center part of the fork stem in order to end up with a stem length the same as what you got from the mock up length. Look ahead a few steps and you will see how things should look when completed.


70


Steering

Figure 83 - Re-welded fork stem

As shown in Figure 83, the only indication that this steering system was shortened is the welded joint in the center of the fork stem. When re-welding the stem together, it's easy to keep the two parts parallel if you place them in a gooseneck, and then clamp the two halves into a vice. Remember to remove the gooseneck before welding the joint, or it will become a permanent fixture! Also, ensure to install the bearing race onto the fork stem before welding, or you will never be able to slide it over the welded area. A bit of masking tape will keep it safe from welding spatter.


71


Steering

Figure 84 - Test fitting the fork hardware

Figure 84 shows what the under seat steering parts should look like after the shortening operation. There is about an inch of thread sticking out past the top of the bearing race, just enough to install the rest of the fork hardware like it was on the srcinal bicycle. You may need to grind a bit of weld material away from the fork stem joint to slide the stem into the lower bearing cup, but only remove as little as necessary so that you don’t weaken the joint.


72


Steering

Figure 85 – Trimming the fork crown

The large beefy chunk of fork crown material is really not necessary in our under seat steering mechanism since it will no longer be used to support the front end of a bicycle, so it can be removed. Mark a line about half an inch below the bearing race and cut the unnecessary material away as shown in Figure 85, being careful not to nick the bearing race with the grinder wheel.

Figure 86 – Securing the fork crown tubes


73


Steering

After you have cut the thick stub from the fork crown, a weld must be made all the way around the underside as shown in Figure 86. If you look closely at the area that you just cut, you will notice that it is actually made up of two tubes that fit together, not a single thick tube. The part you are throwing away would have a welded area just like the one you are about to make in order to ensure that the two parts do not fall apart. This weld is very important, and if it is not done, your steering could completely fail since the control arm will only be welded to the outer tube that is fit around the fork stem.

Figure 87 – Trim the clamp from the gooseneck

In the under seat steering system, it is the head tube that does the moving, not the fork stem. A gooseneck clamp is used to hold the handlebars to the steering system so that you can experiment with the handlebar style or angle anytime you want to. Cut the handlebar clamp from the gooseneck as shown in Figure 87, leaving about an inch of material to work with.


74


Steering

Figure 88 – Fitting the clamp to the head tube

As shown in Figure 88, the clamp will be welded to the center of the head tube, so the joint must be ground to fit properly. It is important to weld the part together so that the handlebars will be perpendicular to the head tube. If you install a straight mountain bike handle bar into the clamp, this will give you a good visual reference point to work with as you align the two parts. Place the head tube on a flat surface and ensure that the handle bar is parallel with the ground.


75


Steering

Figure 89 – Gooseneck clamp installed

Figure 89 shows the completed head tube and handle bar clamp unit. This is another weld that must be done properly, since you will be hanging on to those handlebars.


76


Steering

Figure 90 – Rounding off the crown area

Because the fork stem will be welded to the underside of the main boom, it must be ground to fit properly as shown in Figure 90. Round out the two edges of the fishmouth only as much as needed so you don't completely remove the bead of weld that was made earlier around the ring where the two parts of the fork stem are joined. There will still be plenty of weld on the two parts of the tube to keep it from separating.


77


Steering

Figure 91 – Installing the steering system

The optimal position for the under seat steering system will probably be about 4 inches from the end of your seat as shown in Figure 91. Of course, we all have different ideas of what is most comfortable, so the best plan is to install some handlebars and have a helper mark a line so that you know exactly where you feel most comfortable.


78


Steering

Figure 92 – Under seat steering system installed

The fork crown joint will be completely welded to the underside of the main boom as shown in Figure 92 once you determine the best place to install it. The fork stem should form a 90 degree angle to the main boom, as well as being inline with the other frame tubing.

Figure 93 – Choosing your handlebars


79


Steering

The choice of handlebars is almost endless, and much depends on your size and preferences. To find my optimal hand position, I sit on the seat, drop my arms to my side, and then lift my hands so that my forearms are parallel to the ground. Most of the time, the “granny style” curly bars shown in the bottom of Figure 93 are perfect. If you need a little more room between your hands, then a wider set of handlebars like the ones shown at the top of Figure 93 might work out better for you. Straight mountain bike handlebars seem to offer the least amount of comfort as they require you to reach too far down. Another option is to cut up two handlebars and re-weld them back together to suit your needs.

Figure 94 – Handlebars installed

The handlebars are shown installed in Figure 94 after adjusting them for optimal comfort. Also shown is one of the four 2 inch long control arm welded to the lower part of the head tube on the left side of the bike. This control arm will link the steering to the center fork stem as shown in Figure 97. It is important that both control arms live on the left side of the frame so that the front chainring does not get in the way of the control rods. You can see this earlier as shown in Figure 39. All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

80


Steering

Figure 95 – Spherical bearings and a control rod

Once you have the two control arms welded to the steering system, a pair of ball joints (spherical bearings) and a control rod will link the two parts together. The ball joints will connect to the control rod after welding a bolt at each end so that slight alignment corrections can easily be made. The ball joints are small hardware store parts that have a 5/8 or slightly smaller bolt hole. The control rod is a ½ inch steel rod with a wall thickness of about 1/16 inch. The control rod is cut to a length that will allow both ball joints to be placed into the rod so that the steering can be slightly ‘fine tuned” to align both the front forks and handlebars. To calculate the control rod length, place the front fork stem and steering system in the straight ahead position (see figure 97) and then measure the distance between the holes. The ball joint hole-to-hole distance should match, with a little room for alignment either way when completed.

Figure 96 – Installing the ball joint into the control rod All content © copyright Atomic Zombie Extreme Machines. All rights reserved. www.ATOMICZOMBIE.com

81


Steering

Once the bolt is securely welded to the end of the control rod, the ball joints can be screwed in, allowing a little bit of adjustment room to align your steering properly. To get the bolts welded to the ends of the control arm properly, place two nuts on the threaded part, and then place the ball joint threads into the rod so you can tack weld the nut in place. After tack welded, remove the ball joints and weld the nut all the way around.

Figure 97 – Control arm installed on the front steering system

As shown in Figure 97, the main control arm will link the front steering system with the pilot’s steering system. The front ball joint needs to be placed on top of the control arm so that the other control arm can pass underneath. You may also have to trim the bolt so it does not strike the lower control arm. Also, if the ball joint bodies seem to rub on the control arms, you can add washes to lift the ball joint, and even bend the control arms with a wrench slightly.


82


Chain Management

Chain Management

Figure 98 – A great tool for any bike builder

The chain on the TriCruiser is more than twice as long as that on a regular bicycle, so you will have to join a few same sized chains together. The inexpensive chain link tool shown in Figure 98 is a great investment, and can be purchased at just about any bicycle repair shop. After joining a chain link, bend the chain back and forth laterally, to loosen the link pin.


83


Chain Management

Figure 99 – Cutting the chain to the correct length

The chain will pass under the seat and over the handlebars as shown in Figure 99. Put the chain on the largest front chainring and the middle rear chainring, and then join a length that places the rear derailleur in the position shown in Figure 99 and 100). Some adjustment may be necessary later on.

Figure 100 – Adjusting the chain length


84


Chain Management

The rear derailleur will be in a position similar to what is shown in Figure 100 when the chain is set up to the correct length. The chain is sitting on the largest front chainring and the center rear chainring.

Figure 101 – Position of the chain under the seat

As shown in Figure 101, the chain has two problems at this point. It rubs on the underside of the seat as well as on the handlebars, so a few idler pulleys will be needed to route the chain properly.


85


Chain Management

Figure 102 – Installing the first idler pulley

Idler pulleys are hard nylon or steel pulleys that have a diameter of 3 to 5 inches and include a center ball bearing. Idlers made for half inch v-belts can be found at any lawn and garden equipment store, as well as many hardware stores. Soft rubber pulleys such as skate blade wheels should not be used as they will wear out quickly and create extra friction in your driveline. Figure 102 shows the position of the first idler pulley as it pulls the chain under the seat (shown by the white arrow). Keep your front cranks held stationary so the chain is pulled tight as you test the chain and seat clearances.


86


Chain Management

Figure 103 – Installing the first idler pulley bolt

Once you have tested the position of the first idler pulley, weld a bolt to the frame as shown in Figure 103. You might need a few washers or another nut to create a spacer to place the pulley away from the frame tubing a bit as I did. Weld the bolt all the way around, as it will see some decent forces when you are pedaling with a lot of energy.


87


Chain Management

Figure 104 – First idler pulley installed

The first idler pulley is shown installed in Figure 104, pulling the chain clear off of the seat as needed. The return chain is still rubbing on the handlebars, but it will also be taken care of soon enough.


88


Chain Management

Figure 105 – The second problem in the drive line

The drive chain will also have issues with the rear chain stays as shown in Figure 105 (white arrow), since it is crossing them right in the center or somewhere close. The second idler pulley will cure this problem as well.


89


Chain Management

Figure 106 – Positioning the second idler pulley

The second idler pulley must send the drive chain over the chain stay so that there is no rubbing. As shown in Figure 106, the optimal position for this pulley will likely be the pivot point on your rear suspension system. By placing the pulley here, all pedal induced suspension bounce is completely removed because the chain will now run parallel to the chain stays. Pedal induced bounce can be very annoying on some bikes that do not consider this quirk. If I wanted a pogo stick, I would buy one!


90


Chain Management

Figure 107 – Drive chain management completed

Figure 107 shows the two idler pulleys guiding the drive side of the chain under the seat and then over the chain stays. The second idler pulley is bolted right through the pivot on the rear suspension, but your parts may differ, requiring a bolt to be welded to the pivot area instead.

Figure 108 – Parts for a return chain guide

The return chain (currently rubbing on the top side of the handlebars) is under no tension whatsoever, so you can guide it around using nothing more than a bit of garden hose and a few clamps to hold the hose to the frame. Figure 108 shows a 16 inch long chunk of garden hose or


91


Chain Management

hot water heater hose that has an inside diameter large enough to allow the chain to flow through it freely. The 1/16 inch sheet metal also shown will be cut into strips to make chain hose clamps.

Figure 109 – Bending the hose clamps with pliers

The thin sheet metal is bent into round clamps (Figure 109) to hold the chain guide hose onto the frame. You can also use thin metal rod as well.

Figure 110 – Making the hose clamps

Since one of the hose clamps will be connected to the idler pulley bolt, the appropriate sized hole is drilled into it as shown in Figure 110. The length of the hose clamps depends on


92


Chain Management

where your chain guide tube needs to be, so it is a good idea to install it onto the chain to determine the best position before cutting any sheet metal.

Figure 111 – Chain guide hose installed

As shown in Figure 111, the chain guide hose will route the return chain over the handlebars and out of the way of the drive chain. Since the return chain is never under any tension, you can place the hose just about wherever you need to route the chain properly.


93


Chain Management

Figure 112 – Transmission completed

The completed chain routing is shown in Figure 112, and your TriCruiser is actually functional minus any ability to shift or stop. Do you have enough patience to complete the rest of the bike before you take it out for a spin?


94


Final Steps

Final Touches, Painting and Adjustments

Figure 113 – Making caps for the front head tubes

The only visible open tubing left on the TriCruiser is at the top of the three front head tube since there are no goosenecks installed there. A nice professional-looking fork stem cap can be made by simply welding a washer to the top fork nut as shown in Figure 113. If you take your time and grind the metal up nice, it will look like you actually found a source for this custom cap. This only works on the steel hardware, so find a chromed part to weld.


95


Final Steps

Figure 114 – Watching paint dry

The last step is to clean and paint your frame so that you can get out there and ride. Remove all of the components and check over the welds, filling and grinding any pits as necessary. A light sanding with some emery cloth is all that is needed in order to prime and then paint the frame. Spray cans will give a good paint job if used properly, so read the instructions and take your time. I prime one day and then paint the next so the primer has a day to cure. Figure 114 shows my freshly painted frame after spraying it in the back yard.

Figure 115 – Cleaning up tarnished aluminum


96


Final Steps

The nice thing about aluminum parts is that they will always clean up like new with a little steel wool. The dirty old rim shown in Figure 115 becomes new again with a little scrubbing. It does take a while to get around the entire rim on both sides as well as the center, but the results are worth the effort.

Figure 116 – Assembling the transmission parts

Once you have the wheels installed, add the bottom bracket and then the transmission parts as shown in Figure 116. All parts should be cleaned and re-greased. This is something that you should do at least once a year.


97


Final Steps

Figure 117 – Adjusting the derailleurs

Once you have your chain and derailleurs installed, they will need adjusting. To adjust both the front and rear derailleurs, set up your trike so that you can freely pedal the rear wheel. Both derailleurs have a pair of adjustment screws marked Min and Max, and they need to be adjusted so that your chain reaches the full range of gears but does not shift right off the last gear. The Min and Max adjustment screws are shown in Figure 117 for both the front and rear derailleurs. Pedal and shift to determine if you can reach all of the gears. If you can’t, then adjust the screws a bit at a time. If your chain shifts right off of the last gear, then you went too far. Simple, yet somewhat tedious!


98


Final Steps

Figure 118 – The completed TriCruiser

The completed TriCruiser is shown in Figure 118, ready for launch. You will probably need to try all of your gears and brakes by heading around the block a few times before you set out on any epic journeys. If you can reach all of your gears and stop in a hurry, then you are set. There is certainly no learning curve when it comes to riding a trike, but you will have to learn the limits of both the steering system and the speed at which you can take corners. Being a more upright and narrow trike, the TriCruiser will be able to get up on two wheels quite easily if you make a hard turn while moving at any speed. Learn the limits of your trike and keep them in mind when hitting corners or riding in busy traffic. In the winter, this is much less of a concern since you will be trudging through the snow!


99


Final Steps

Figure 119 – Enjoying a relaxing cruise

We hope you enjoy building and riding your recumbent trike as much as we have! The results of your hard work will certainly be worth it, and nothing can compare to the feeling of riding your own quality built recumbent trike. We hope to see your work or progress in the Atomic Zombie forum, and would certainly be happy to post a photo of your completed trike in our Builders Gallery for other builders to see. Once again, thanks for our support, and good luck on all of your projects! Brad Graham and Kathy McGowan, Atomic Zombie™ Extreme Machines

Click the icon below for instant access to daily Atomic Zombie news:


100

Tri Cruiser

Recommend Documents