I have a 1996 built Vision R40 SWB, underseat steering recumbent. It's a chromoly steel construction. I bought it around 2007, made some upgrades to indexed shifters and put in an 8sp cassette early-mid 2010's. Then life happened and its been hung up in my garage for the better part of a decade.
I'd kinda like to make it into a gravel bike. I doubt, as is, I could get enough selling it to be worth the effort, ghosting buyers, etc. I'd hate to junk it.
For gravel riding I'd want tubeless, which means new rims. If I'm getting new rims anyway, going from stock 26" to 650b on the rear opens up a ton of tire options. Not sure about the front wheel, currently it's 16", was thinking 20" would have a ton more tire options due to being a popular size for folding bikes. That would mean a new fork, and given the handlebar mounting that probably means a custom fabrication. But with a new fork I could also increase the wheelbase a little which would improve handling (i.e. make it less twitchy).
I'd like to upgrade from the existing 3×8 drivetrain to a 1×11 at least, a 1×13 would be fantastic. 2×10 at an absolute minimum. And disk brakes (hydraulic, if I'm doing all of this as it is might as well go all the way). The rear wheel dropouts would likely have to be widened to accommodate a 10-13sp cassette. I can probably fit the diameter of a 650b without major surgery, but the tubes leading to the dropouts probably should be a bit heftier to handle disk brake loads, and if I do that, might as well add the 0.75" of length to maintain clearances.
I think flat bar brifters would work with the existing handle bars. Guessing the change to 1x (or 2x) would require new cranks, and probably a new bottom bracket. Hopefully the tube that holds the BB is the right size.
My son is a talented welder, so any cutting and welding is something he can probably handle. Not sure about getting post weld heat treatment, but I'm sure there's a machine shop somewhere I could pay for that.
Is this a dumb idea, or a good project?
by Lost_War7375
2 Comments
If anything, you’d want to downsize the wheel diameter and not upsize them so that you can use a wider tire and still have adequate frame/fork clearance.
Gravel can be an unstable surface, so helping to ensure your tires/wheels don’t “knife“ into it seems paramount – especially on a recumbent where you are much less able to use body English to control the bike. Therefore, a very sure-footed contact patch for each tire is essential. Nothing will help ensure that quite like the widest tires your bike can accommodate. I hope that makes sense.
That all said, since the bike has cantilever brake mounts, you will have to move them in order to accommodate a different diameter wheel, or have disc brake mounts, retrofitted onto the frame and fork.
What is your rear drop out spacing? You’ll need either 142mm or 148mm for modern 1x drivetrains and disk brakes. An older bike like that might have 128mm. Disk brakes generally require a reinforced fork as the entire braking force is near very end of the fork blade rather than near the crown. Not sure if I would trust disk brakes with quick release on a jury rigged fork on a heavy recumbent on a steep rutted descent.