I see that people are trying to create a unicycle with shifting capabilities. Why arent people using a modified Nexus hub with internal gears? It seems that with some modifications, you could mount a pair of cranks to it.
Thanks
I think some people have done with sturmey archer hubs
there are problems though, for several reasons, including
a) bike geared hubs aren’t fixed gear and they’re only designed to take forces in once direction even if you were to disable the freewheel.
b) bike hubs aren’t designed to be driven by the centre axle.
Joe
The reason I ask is that I want to build a bicycle without a chain or shaft. Basically a unicycle design with a front wheel. But still keeping some resemblence of the road riding position.
But I would still like to have shifting capability. I thought of the reasons you mentioned for not using a Nexus hub, but think the issue of converting a Nexus hub to a drive axel might be possible.
UniFrank made a geared hub using the parts from a used Nexus hub. UniFrank’s web page Click on English Version then Planetary gear hub
There’s a little bit more info in this thread
Greg Harper has also made a geared hub. Drawings and info are on his web site.
Schlumpf is now making a commercial version of the planetary geared hub
Then there is the Outta Phaze jack shaft geared design. But it’s not shiftable. The design of the Purple Phaze or Outta Phaze frame may give you the riding position you’re looking for.
maybe do something like this? it’s got a 3-speed geared hub.
Wow, that looks like an offroad ENDO-CYCLE! I see suspension on the front wheel, but no apparent room for the wheel to move upward.
In otherwords, at first glance it appears to me like an extremely dumb vehicle for riding off road. I would think the rider would want to be further toward the back, rather than the front, to prevent endos. But then again, I never rode a tricycle on mountain bike trails either, so maybe it works great!
Similar question for maxmyer. If you’re pedaling directly off the wheel axle but want a bike-type riding position, your center of mass is going to be pretty close to directly above the axle. I would recommend more of a relaxed, or even recumbent position.
I’m only going on what I was told by the rider, it’s likely that I’m correct. it’s a freewheel hub too. I was most disappointed when he told me!
John, you have no idea how right you are about it’s unsuitability for off-road! he was under team instructions to do a slow last lap a t Mountain Mayhem, so thought he’d give this a go. At this point, 6 miles into the 10 mile lap, the rear wheel was barely spinning due to the disk brake, and a front brake block had fallen off! it only cost £50 off ebay though so he wasn’t too unhappy. he was overtaking a lot of riders on the downhills too!