HOW TO BUILD AN INEXPENSIVE SUSPENSION RECUMBENT BICYCLE AT HOME PART 4

Now that the seat is installed, it's time for the job that will rack your brain big time: chain management. On regular bikes this is pretty obvious, the chain goes straight from the chainring sitting in front of the rear wheel not too far ahead.

In our case, the chain has to make a few detours to get from the chainring to the rear wheel and must avoid a whole bunch of things on it's way there and back. Before you start making your chain management set up, make sure you install everything on the bike, brakes, cables and every little doodad that goes on there. You must know what will be in the way of the chain before you install it. Remember, we're not working with plans here! One of the easiest ways to bring the chain from the rear to the front is with black PVC type tubing. I use the kind that is put in the ground for lawn sprinkler systems. 100 feet for $12, it should last you a lifetime. Those types of tubes usually last one season, so all the extra is not for nothing. It is surprisingly quite, you just have to make sure you secure the tubing with a good amount of duct tape strategically placed so the tube doesn't move with time. Leave the very front and back of the tube loose so that the chain can move when shifting from one gear to another.



That takes care of the top part of the chain, now for the lower part or the return section of the chain. When the chain is moving in the lower section, it isn't under tension and we can get away with less strength in our deviation set up. I use a grinded rollerblade wheel secured at the old bottom bracket by using a front wheel axle jerry rigged on the left bearing cup. It holds pretty nice and is very quite. I allow the wheel some movement on the axle so the chain can remain more straight in its path back to the rear wheel. I also added another wheel which I made from an old printer bracket wheel that I attached to the clip that holds the front boom. I sandwiched an old derailleur wheel on it. I used that one to clear the top of the fork while the chain is on its way back to th rear of the bike. I could have used another rollerblade wheel type of arrangement there as well, but I already had that set up lying around.



Now at this point the bike can be powered. Before you start installing all the accessories and other little knick knacks, install a working rear brake and take it out for a ride to see if your prototype is actually functional. I did with mine and that's when I found out that...

IT'S A TOTAL FLOP!

Yes, sadly this is a possibility when you hodge podge a homebuilt bike together. Before I started this build, I figured there was going to be some flex when pedaling the bike caused by the rear suspension, but I wasn't expecting that much. The thing bounces around like a clown bike when under full pedal power from a dead stop. Climbing hills is just very hard labor and extremely slow. I had tightened up the spring on the cheapo shock absorber, but it wasn't enough.

Mind you, the suspension does its job while going downhill or when you're up to speed on the flats. But unless you want to train to get legs like Lance Armstrong, going on even the slightest incline is murder for your leg muscles. There might be a way to lock the shock when you need it or a better quality shock might work better, but I don't have the time or money right now. I need a working recumbent for a big critical mass event in 2 weeks. Not only does it need to work, it also has to be broken in, no time to do repairs on a big ride like that. So on with:

PLAN "B"



Plan "B" is my previous short wheel base recumbent that my son affectionately called the "Pocket Rocket". It is made from and old CCM mixte frame. It runs on a 20 inch rear wheel and a 16 inch front wheel. I had some elements like the front boom and brake bosses welded on by a welder for hire. Cost of the welds back then came to about $20. Next post will be about slapping the Rocket back together. Sorry about this let down, but things like these happen when you make stuff yourself from junk. Remember that practice makes perfect.

Til next time, ride safe and Godspeed.

Gerry :)

Homebuilt recumbent part 1
Homebuilt recumbent part 2
Homebuilt recumbent part 3

HOW TO BUILD AN INEXPENSIVE RECUMBENT BICYCLE AT HOME PART 3

Well it's been a while, but the snow has finally melted and the Sun has decided to come out. So it's time to build bikes again. In this post I will talk about 2 sections of the build, the steering column and the seat brace and seat, so off we build!

MAKING THE STEERING COLUMN

This recumbent has over the seat steering. This requires for the handlebars to clear your legs while they crank the pedals. I accomplish this by using a few parts from scrap bikes.

Part 1 is a stem that I took from a mountain bike. I removed the clamp that holds the handlebar and kept the sides so that I could attach the second part. Part 1 actually goes into the steerer tube of the fork, it's the main stem.

Part 2 is just a piece of frame from the top tube of a racer bike cut to lenght. I then drilled some holes so I could attach it to Part 1, the main stem.

Part 3 is a regular road bike stem that is shoved inside Part 2 and tightened up as usual. I chose a road stem since I wanted the handlebars close to me.

Part 4 is a pair of moustache handlebars that can usually be found on old roadster bikes. You can also use a regular flat bar. I chose these because that is my riding position of choice.

Get all this stuff together, bolt everything real tight and you have yourself a steering column for your recumbent. Did I mention bolt everything tight? Don't skimp that part for later.





THE SEAT BRACE AND SEAT

The seat brace was going to be a challenge on this suspended bent. I couldn't use the rear stays for support since they are moving. I found the solution in some left over tubing from an old bike rack. The tubes were pre-bent to shape. I flattened the bend to add some strength, drilled a bunch of holes in the tubes, bike frame and then I bolted everything together tight with nylon lined bolts. The seat is just 2 pieces of plywood slapped together with door hinges and bolted to the braces in the appropriate holes.

This set up is my worst looking educated piece of guesswork that I have ever done. Awkwardly, it is also the most sturdy! The seat will have some fine adjustement done later on and will be padded. The rear suspension will take most of the hits, but plywood is still not that comfy, it will be padded.



The next installement of this build will be about chain management. This is the part where you get headaches.

Remember that if you are building one of these things, overbuild and tighten every thing down hard. In this build alone so far I have 10 added combination of nuts and bolts not found on a regular bike. That means 10 other things than can go wrong, don't forget it.

Til next time, ride safe and Godspeed.

Gerry :)

Homebuilt recumbent part 1
Homebuilt recumbent part2
Homebuilt recumbent part 4