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No weld rear wheel drive recumbent “la Vronimatik”

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Picture of No weld rear wheel drive recumbent “la Vronimatik”
This bicycle is really easy to do, cheap, and does not require any welding skills.

Front wheel drive recumbents not requiring welding are popular in instructables:

http://www.instructables.com/id/Front-Wheel-Drive-Center-Steer-Semi-Recumbent-Bicy/
http://www.instructables.com/id/Chucks-No-Weld-Recumbent-Bike/
http://www.instructables.com/id/No-Weld-Recumbent-Modifications/
http://www.instructables.com/id/DIY-recumbent-bicycle-made-from-recycled-parts/

I did one myself :  http://www.instructables.com/id/simultaneously-pedalling/

These front wheel drive bicycles are easy to build, cheap and do not require welding. However, they have two main  problems: steering is affected by pedalling and traction is lost uphill because the weight is shifted to  the rear wheel. You may get used to compensate the steering influence of pedalling but it will always be impossible to use the bicycle on a hilly terrain. My rear wheel drive bicycle overcomes these problems while keeping the simplicity of construction of the front wheel drive ones.



 
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Step 1: Materials

Picture of materials
For building this bicycle you need:


- Two bicycles. From one of them only the crank related parts are used.

- Two clamps (10 €) of the kind used to fix parabolic antennas.

- Two plastic tubes, inner diameter should allow passage of the chain. I bought chain tubes made specially for bicycles (5 €), but you may use any tube, for instance those black tubes used for irrigation.

Step 2:

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Cut the frame of one bicycle and fix it to the the other one with the clamps as in the photos.

Step 3:

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Join the two chains (http://www.instructables.com/id/How-to-repairassemble-a-bicycle-chainwhile-keepi/  http://www.instructables.com/id/How-To-Fix-a-Bike-Chain/) and guide them through the plastic tubes.


The upper section of the chain should be straight, the lower doesn't. Keep the end of the tubes close and aligned to the gears.

To guide the chain with tubes is easier an cheaper than using pulleys, springs and gears.

Step 4:

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The distance of the seat to the crank should be adjusted to your legs lenght. You may either move the seat or move the crank when fixing the clamps.

The position of any bicycle seat may be shifted some centimetres horizontally, just by loosening the nut and moving the seat. In order to move it even further; I turn 180 degrees the seat clamp, as in the image.
burb7227 days ago

very nice, your build changed the design of the one im doing

m a r i a n o (author)  burb7226 days ago

Thank you! Please tell me about your bicycle when finished.

Advar11 months ago
Nice job. Now I don't need to pay someone to do some welding for me- clamps!! One of those "Why didn't I think of that?" things. Thanks!
m a r i a n o (author)  Advar11 months ago
Thank you
estructor11 months ago
Clever way to fabricate something without welding; good use of a sacrificial rear triangle in order to obtain and attach a bottom bracket/crank housing shell.
--Not sure I agree with the "traction" logic about weight over rear wheel. More weight over the drive wheel actually improves traction. The fore-and-aft weight distribution on many recumbents does affect steering though, as you said. It makes the front lighter than on a traditional bike. The steering wheel doesn't respond as well, the front wheel can 'wash out' more. The rearward weight distribution makes the front get even lighter on an incline, with less ability to move your body's ballast over the steering area due to the recumbent position. Perhaps you meant to refer to this dynamic, because 'popping a wheelie' inadvertently on a hill certainly affects traction; inasmuch as most of us on a recumbent would then fall over... But with low enough gears I daresay hill climbing isn't 'impossible,' just more difficult.
I still like your build, it fits my 'Swiss Family Robinson' ethic of being able to make what you need with what you have on hand!
m a r i a n o (author)  estructor11 months ago
Thank you for your comments. I check your "Three Wheel Bike Car", great vehicle.

About the traction: I did built the same bicycle with front wheel drive and I could not climb steep hills because traction was lost. With real wheel drive I can climb the same hill without problems. May theory may be wrong, but my experience is conclusive.

May be I don't make my point clear with the traction theory, by loosing traction I meant that the wheel turns but the bicicle does not move because contact of the tire with the ground is lost. My English is quite bad, please excuse me.
Mariano,
Don't worry about your English, you do pretty well. It was perhaps my mistake--I just did not know you were referring to a front wheel drive version, when you spoke about traction. In that case you are of course right, the front wheel loses traction on hills, just as you say.
m a r i a n o (author)  estructor11 months ago
The original description was a bit confusing. I amended the passage. Thank you for pointing out the problem.
audreyobscura11 months ago
What a sweet mod! I also would have never thought of using old bike tube as a chair back. Smart!
m a r i a n o (author)  audreyobscura11 months ago
Thank you
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