Recumbent - Converting a Diamond Frame to Recumbent?

Is it possible to convert a diamond frame into something like a recumbent?

Is it possible to convert a diamond frame into something like a recumbent?

No. Unless you want to give a broad definition to "something like a recumbent".

A decent bent is going to cost you some $$$. Forget about conversions. If the budget is too tight, watch Ebay and Craigslist. Decent stuff comes up regularly.

really?... And just what is your definition of "recumbent" Wildwood?

And does this qualify?

http://www.cruzbike.com/

That's a recumbent, but it didn't start out as a regular diamond frame. It's more of a "Y-frame." If I read the Cruzbike site correctly, their kit is really designed for the double-suspension MTB's. I was thinking about converting my DF bike to a Cruzbike, but the straight, level, rigid top tube would interfere with the correct placement of the seat (I think.)

recycledrecumbents.com and do some math on costs

That's a recumbent, but it didn't start out as a regular diamond frame. It's more of a "Y-frame." If I read the Cruzbike site correctly, their kit is really designed for the double-suspension MTB's. I was thinking about converting my DF bike to a Cruzbike, but the straight, level, rigid top tube would interfere with the correct placement of the seat (I think.)

You are correct, the Cruzbike is really meant as a Y-frame conversion. However, you can also use a mixte frame with some creative bracketry for the seat mounts. Shouldn't be too costly to find an old mixte frame at your local thrift store, then swap components and add the Cruzbike kit.

Or, as bbwolfy mentions, you could cut up two old DFs to make a Toureasy clone. But if you're gonna go that far, go all the way:

I read somewhere that it's bad to have the feet way above the seat. Curculation/gravity or something like that?

There is (or maybe was) a company in Washington state selling plans for building your own recumbent from donor bikes. A friend did that and produced a somewhat heavy but nice looking recumbent. He did buy a few new parts and the total cost including painting it himself was around $300. The supplier did provide some of the parts for the recumbent. My friend soon went on to buy a used a used 2-wheeled recumbent and than a really fine used GS GTO trike. He didn't pay all that much more for the used recumbent than for the one he built. You may be able to find some links at the Gaerlan bike shop site - www.gaerlan.com. It is also a good souce of recumbent supplies. Ditto for Power On Cylcing in Florida.

Take a BMX bike, weld a boom on the front for pedals. Make a seat out of two pieces of plywood joined by a piano hinge, and bolt it to the top tube. From there, the more sophisicated you want, the more welding will be required. Starting with a larger upright frame results in a higher seat. Here's a couple of examples:

http://www.recumbents.com/WISIL/junkbike/junkbike.htm
http://www.recumbents.com/WISIL/junkbike/forrestbike.htm

There was an informal survey on BROL awhile ago about what was the easiest recumbent to build. Although there was never really a final answer to that question, the general consensus was that the BMX conversion was probably the quickest way to get a swb homebuilt recumbent.

But if you're going that route, then I think a dual 26" or dual 700c like the JRex/Junkbike would be the way to go. Same number of welds, but you end up with a faster bike.

Every time I see a picture of this bike, it makes me want to go cut up a DF and start brazing. It just looks fast!

There was an informal survey on BROL awhile ago about what was the easiest recumbent to build. Although there was never really a final answer to that question, the general consensus was that the BMX conversion was probably the quickest way to get a swb homebuilt recumbent.

But if you're going that route, then I think a dual 26" or dual 700c like the JRex/Junkbike would be the way to go. Same number of welds, but you end up with a faster bike.

Every time I see a picture of this bike, it makes me want to go cut up a DF and start brazing. It just looks fast!



Hey, that looks just like John's junkbike. hmmm maybe it is? I thought there was a carbon fork on johns junkbike though.

Hey, that looks just like John's junkbike. hmmm maybe it is? I thought there was a carbon fork on johns junkbike though.

Nope, that's my junkbike but it doesn't have a carbon fork. In fact, I may end up stealing that nice aluminum fork for converting my V-Rex to dual-26, if I can find a steel fork for 'J-Rex.'

If you could find a 13" mixte frame or a sloping top-tube, then you wouldn't even have to do any cutting to make one like this, just weld a boom on the front and a few fittings for idlers. A 15" frame might work, depending on how long your legs are.

You can see several bents ("or something like a recumbent") made from other bikes, scooters, lawnmowers, bedposts, lumber, driftwood, skis etc at: www.woodenbikes.com

Its a site about trying out your own ideas.

The world hour bike speed record was held recently by an ameture rider on a home made bike using a Washing Machine bearing as its BB.

I read somewhere that it's bad to have the feet way above the seat. Curculation/gravity or something like that?

As long as you stay within certain design parameters, I think this is a personal preference. The two symptoms that seem to plague recumbent riders are 'recumbutt" and numb feet. If you bottom bracket is too high, you may get numb feet. If it's too low, you are gonna get recumbutt. Of course I speak in generalizations. Some people find that they cannot balance well on a lowracer type bike, in which your feet are almost always located higher than your hips, but this has more to do with not being able to shift your body mass around to shift the center of gravity.

I think I have seen stated that the max distance you would want the bottom bracket about the seat is approx. 9 inches, and my bike falls within that range.

Great ideas folks! I'm planning on converting an old Raleigh 20 folder to a SWB bent, similar to the BMX conversion above. I thought I'd Tig a boom out front for a bottom bracket, use a front derailler and chain to the existing crank, then put an 8 speed internal hub on the rear. Don't know if it will work or not but the 4130 steel just came today. Thanks for the above web sites - very informative.

YOu guys are great, thanks for all the great ideas. I'm buying my own welder soon.

I took a 20" bmx and a 16" barbie kiddie bike and plan on making a SWB out of them. I plan on using a 20" fork for the rear and the center part of the Barbie bike upside down for the front boom. But the pedals look like they may be too close to the front wheel, I'm experimenting. I want to use a 3-speed Sturmey Archer rear wheel, rather than rig all the chain for a derailer. This isn't a time trials bike, just something to play with and experiment with. I think 3-speeds are underrated personally.

YOu guys are great, thanks for all the great ideas. I'm buying my own welder soon.

I took a 20" bmx and a 16" barbie kiddie bike and plan on making a SWB out of them. I plan on using a 20" fork for the rear and the center part of the Barbie bike upside down for the front boom. But the pedals look like they may be too close to the front wheel, I'm experimenting. I want to use a 3-speed Sturmey Archer rear wheel, rather than rig all the chain for a derailer. This isn't a time trials bike, just something to play with and experiment with. I think 3-speeds are underrated personally.

I'm trying to build a 24" wheel, three speed Tadpoltype recumbent trike for the wife! Alternatively, I'm thinking of a three spd hub and a three ring crank, any suggestion or avoid this route warnings?