Easy Build Recumbent

All pictures and text COPYRIGHT 2003-2018 by J Sheehan

These are the easiest to build, best looking with NO WELDING required, Short Wheelbase Recumbent bike plans you'll find! This is so easy and fun to build, I'll bet you'll be building more for friends and family!

Next we need to do the legal stuff:

These plans and completed project are to be used at your own risk, I assume no liability for injury or damage arising from the use of these plans, suggested tool use, or operation of the completed project bicycle.

Ok, let’s get started!

PLEASE read these instructions thoroughly and look closely at each picture (there are also extra pictures at the end) before beginning so you'll have a good idea of what items you'll need and what to be on the lookout for. Don't worry if you read something that you don't understand, it'll start to make sense as you start building.

1. Find your "X" seam:

For this step you'll need a tape measure and a piece of board that is long enough to act as a back rest. Place the board against a wall at a comfortable angle and sit down in front of it with your shoes off and your butt against the bottom of the board. This should simulate a reclined position like you'd have in a car. Now with your legs straight out in front of you, measure from the bottom of the board out to the end of your heel, this is your "X" seam. This is WILL be longer than the inseam of your pants. If you've got a memory like mine you should write it down for future reference.

2. Gather Parts:

In this step you can go crazy, that is if you’re a garage sale nut case like me. I kept finding good deals so I kept buying them (my poor wife), I didn't pay over $10 for any bike I bought and I got some pretty good bikes. I pretty much stuck with mountain bikes, nice and sturdy. I'm actually building my fourth recumbent now using a brand new bike from Wal Mart ($57) and still doing it for less than $125. I have also just purchased a wire feed welder from eBay and am building a Long Wheel Base Recumbent using all those extra parts I now have lying around, this is too much fun! Hopefully I'll have plans available for a LWB Recumbent in the near future.

Basically you will need three bikes, one 24" or 26" girls bike and one 24" or 26" boys bike. Make sure the girls bike is a good one as you will use it to build on. The boys bike will be the donor bike for parts. Depending on how tall you are defines whether you want a 24" or 26" bike to build on. When in the sitting positing you will want to have your feet flat on the ground like your sitting in a chair. If you're short like myself go for the 24", you tall folks can use the 26" if you want. Look for one's that have three chain rings on the crank, (usually 15, 18, or 21 speed bikes) you'll see why later in the instructions. Two chain ring cranks can be used but you won’t have as many speeds when done. You will also need a 20" kids BMX bike with a good fork, handle bar, and front wheel, look for one with front brakes so you won't have to drill a hole for them.

Note: Before you buy a BMX bike, measure the fork tube length on your builder bike frame and make sure the 20" you buy has the same length. The first one I bought was shorter and wouldn't work because all I could get on it was the bearing nut an no lock nut. Also look for one with the up-swept hi-rise style handle bars, this will help with leg clearance when pedaling. You will also need a 10" or 12" tall handle bar stem. If you run across one of these snag it even if you have to buy the whole bike (more parts!!), otherwise you can probably find one at your local bike shop, if not I got mine from eBay, just search hi rise" or "stem" in the "sporting goods/cycling" category.

3. Tools needed:

If your tackling this project, you're probably a tinkerer like myself and have a garage full of tools. You can do this job with your basic hand tools but you will for sure need a good power drill with sharp bits and a hack saw with a good metal blade. You will need a center punch for marking the drilling points on the metal tubing. Don't try to drill metal tubing without center punching first otherwise your drill bit will wander everywhere but where you want the hole to be. If you have a few 16 penny nails laying around they'll work fine but you'll dull the points a lot faster. A small metal file is handy also for smoothing out those rough edges after you've cut metal. You will also need a chain breaker (chain tool) which can be had from Wal Mart in their bike department for about $3 and it comes with extra chain links for putting the chain back together. If you can't get a chain breaker, a good metal chisel and hammer will do the trick. If you don't already have a set, I would suggest buying a couple of the new style quick release wood clamps, they're cheap and you won't know what you ever did without them, mine are about 20" long. You will also need a 1/4" wood chisel, a cheap one will do as you'll only be cutting plastic with it. One final suggestion would be that you have plenty of room to work in and if you can, set up a nice work table using a 4'x8' sheet of plywood and 3 sawhorses.

4. Parts needed:

2 - 1" thinwall metal tubes. Do not use conduit! These can be had from any hardware store usually in lengths of 36" or more, I got mine from Menards in their hardware department for $6.00 each. Unless you play basketball in the NBA the 36" tubes should be plenty long enough.

2 - Bicycle Tune-Up Kits, available at Wal Mart. These kits come with new longer cables, the originals will be too short when the bike is done, it also contains new brake pads.

1 - tube or can of lubricating grease

1 - regular size skate board wheel and bearings.

Several 1/2" x 3/32" multi speed chain master links, usually found at your local hardware store or bike shop.

The following parts are available at your local hardware store or home center like Menards.

2 - 3" door hinges.

2 - 3/4" Split Ring Pipe Hangers, in the plumbing dept. at any hardware or home store.

3 - 1/4" Pan head bolts 2" long with nylon lock nuts.

4 - 1/4 bolts 4" long with nylon lock nuts.

**The locknut indicated above are regular nuts with a nylon insert, sometimes called aircraft nuts.

1 - 5/16 bolt 2-1/2" long with nylon lock nut, this will be used to bolt on skate board wheel. You will also need a 3/8" standard nut to use as a spacer.

Note: bolt lengths may vary depending on tubing size of the bike you're building on.

1 - 5/16 bolt 3" long, 2 fender washers with 5/16" holes, and a nylon lock nut. These items will be used when cutting a groove in the skate board wheel.

You will also need a piece of wood to make the seat, I used a piece of 3/4" plywood about 10" wide x 30" long, as well as a 12" piece of 3/4" conduit for a back support.

5. Now lets get to work!

Disassemble the bike that you’re going to use for parts, from this bike you will be using the rear derailleur (shifter), chain, crank, and you will also be cutting the crank tube out of the frame. Keep in mind that "rightie tightie, lefty loosey" doesn't apply to the crank nuts as they unbolt the other way (the same also applies to the left pedal). Now cut the crank tube (see picture below) out of the frame making one cut through the lower down tube just behind the fork tube and another through the seat tube just below the upper down tube. You will also have to make cuts at the lower wheel supports at the back of the crank tube.

Next on the kids bike remove the front wheel, handle bar and stem, first removing the shift levers/cables and the brake levers/cables, and then the fork.

On the "good" bike that you're going to build on, remove the following:

Seat and seat post, both pedals keeping in mind again that "rightie tightie, lefty loosey" doesn't apply to the left pedal as it unbolts the other way. Remove the front wheel, handle bar and stem, first removing the shift levers/cables and the brake levers/cables, and then the fork. If you've never messed with derailleur and brake cable assemblies pay attention to how the cables are attached and adjusted so you can reinstall the new one's the same way.

Next reinstall the kids 20" bike fork on your builder bike inspecting, cleaning and re-greasing the bearings in the process. You can reinstall the wheel but I find it handy to leave it off so the bike will stand up on its own resting on the fork.

Now the trickey part, ok it's not that bad. I just want to stress that this is an important part and you need to take your time, this is the part where you drill the holes for everything. Unless you're using a drill press, drilling holes in tubing using a power drill requires all of your attention to get them straight.

First drill 1/4" holes in your builder frame, one just behind the fork tube on the upper down tube and the other in the seat post tube. Where you drill the one in the seat post tube depends on your height and the frame size. For instance I'm 5'5" using a 26" bike frame, I drill the hole below the upper rear wheel supports so my seat is a bit closer to the ground allowing me to sit comfortably with my feet flat on the ground when stopped. Again I stress, these holes must be level.

Next take the two 36" metal tubes, clamp them together making sure the ends are even and then drill a 1/4" hole at one end through each tube about 1" from the end. Then, loosely bolt the two tubes to the bike frame at the seat post and clamp them in place near the front so they're positioned close to the hole you drilled just behind the fork tube. Mark both tubes at the hole and remove them from the bike. Now bolt the two tubes back together, clamp them near where the marks are so they're level and drill another 1/4" hole through both. Doing it this way may seem a bit much but I can't stress enough that these holes must be even.

Remount them to the frame, just so they're snug. Now you're going to mark and drill the holes for the crank tube at the front using the same process. Where you set the crank tube and mark the holes depends on your "X" seam you measured earlier, you may have to cut some off the tubes in this process. Using two pieces of wood and you're clamps, clamp the crank tube to the two tubes at the front of the bike, adjust in or out according to your "X" seam minus 3" measuring from the front of the seat post to the center of the crank tube. The reason you minus the 3" is to compensate for the length of the crank pedal rods, most are 4" to 7". If you wish to be more accurate you can mount the crank you'll be using in the crank tube and measure to the end of the pedal rod at the full out position (leg fully extended) but the added weight makes the assembly cumbersome and hard to adjust. One other reason for mounting the crank is to be sure the pedals clear the front wheel when turning (you will have to mount the front tire too). If your rather tall this should not be an issue as the crank should stick out far enough. Keep in mind the seat will be adjustable so this measurement does not have to be perfect except to ensure the wheel will clear the pedals when turning.

Before disassembling to drill holes, mark a spot on the right tube (chain side) just behind the bolt installed in the down tube, keep in mind there will need to be enough room to accommodate a lock nut. This is where you will drill a 5/16" hole to mount the modified skate board wheel to be used as a chain roller/guide (see idler wheel 2nd picture below). Disassemble everything and then bolt/clamp together so the new 1/4" holes can be drilled through the 36" tubes and the crank tube. Before drilling, lay the assembly flat so you can make sure the crank tube is also square to the 36" tubes and the holes previously drilled, if the crank tube is not square to the frame the chain will come off when pedaling.

After you've drilled all the holes, bolt everything onto the bike frame installing the bolts with the heads on the chain side. On the bolt just behind the fork tube,

install a stiff washer on the head (chain) side and just snug the bolt. You will be installing the spare rear derailleur behind this washer. Do not over tighten the other bolts as you can crush the tubes doing so. When everything's bolted on the crank tube should look something like the picture below.

At this point you can cut the top of the seat tube off. If you mounted the new crank tubes above the upper rear wheel supports then cut the seat tube off even with the crank tubes. If you mounted them below the upper rear wheel supports then cut the seat tube off just above the welds. I this case there will be a bit sticking up which will limit the rearwards adjustment of the seat.

Now remount a crank to the new front crank tube, again cleaning and re-greasing the bearings in the process. You can use either a multi speed crank or the single speed crank from the BMX bike. The tube that's left sticking up can be cut short, or clean off if you wish, but I generally leave a bit sticking up to mount a headlight to.

This next item requires a bit of patience, its better to do it on a drill press but can be done on a hand drill with some help, or by clamping the drill to your work table if it has a locking trigger switch. If not done already, install the bearings in the skate board wheel. Put a fender washer, the skate board wheel, another fender washer, then a lock nut on the 3" 5/16th bolt and tighten till snug. Chuck

this assembly in your drill or drill press and use the 1/4" chisel (I bought a cheap wood chisel) at a 90 degree angle to the wheel to cut a groove. The groove should be cut off center, close to one edge of the wheel and end up about 1/4" wide x 1/4" deep. The chain will be riding in this groove when installed on the bike. Don't go too deep or you'll cut the wheel in half, you just want a little more than half the chain to sit in the groove. When the groove cutting is done mount the wheel to the frame (see picture below) on the chain side using the 2-1/2" x 5/16" bolt. You'll want to put the 3/8" nut between the wheel and crank tube, tighten enough so it continues to spin freely.

Next mount the spare rear derailleur as pictured below, notice the small bolt next to the large bolt. This locks the derailleur in place, I used a small self drilling sheet metal screw here but any sheet metal screw can be used by drilling a small pilot hole first (remember to center punch first). If you look closely at the derailleur you'll see two small screws that are stop adjustments, you should be able to remove both as there should not have to be any adjustments at this derailleur.

Now mount the chain around the front crank, over the skate wheel, down around the inner most (small) gear on the bottom crank, and then through the derailleur as shown above connecting the ends together using a chain master link. You will probably have to put two chains together and then hack some off to accomplish this step so that when completed there is tension on the derailleur (it's spring loaded) there's no slack in the chain (see picture below). The chain might not look like its running true looking at it from the front, you will probably see the bottom running closer to the frame, this is ok as the chain is plenty long and therefore flexible enough to accept this offset.

Now is the time for the seat, you can build and mount it any way you like but here's how I do it.

I start with a piece of 1/2" or 3/4" plywood 10" wide by 30" long, cut diagonals off one end so it looks kind of like a regular bike seat (see picture below), measure in 10" from that same end and cut to make a seat, the rest will be used for the backrest. Now place the two pieces together and mount one of the hinges then mark the center of the seat portion and drill a 1/4" hole at each end, this is where two of the 2" pan head bolts will go.

See picture below, remove the rear brake assembly and reinstall with a hinge between the brake assembly washer and the upper rear wheel support as shown. Now take the 12" piece of 3/4" conduit and drill a 1/4" hole 1" from each end and mount to the hinge as shown.

Mount the seat to the bike as shown below using the half of the Split Ring Pipe Hangers that has the threaded hole using two 1/4" x 2" pan head bolts, the bolts will slide right through not using the threads in the split ring hanger halves.

At this point I use a wood screw through the upper end of the conduit support to attach it to the back rest until I find a comfortable angle and then drill a 1/4" hole at that point for a third 1/4" x 2" pan head screw to do the final bolt down. Tighten all nuts, once again being careful not to tighten so tight as to crush the conduit pipe. Sometime in the future you'll want to get some foam and material to pad and cover the seat. It's really not hard to do, all you need is a staple gun and a bit a patience to make it look good.

All that's left now is to mount the handle bar stem and handle bar, then align them with the front wheel. Next mount the brake and shift levers on the handle bar, install new cables and make adjustments to derailleur and brake assemblies as necessary. At this point in time you should also cut off the lower crank rods to your liking.

Now's the time for your first ride, if you've never ridden a recumbent before it's a bit tricky at first but after about 5 or 10 minutes you'll have it down no problem, watch those first turns!

EXTRA PICTURES:

All pictures and text COPYRIGHT 2003-2016 by J Sheehan