Shaft Drive

[Dean W]

I am really surprised that more attempts at shaft drive have not been made.

A HT with shaft drive would be sweet. Imagine the BB clearance. It could also be used on single pivot designs like the Scarab or the Cove G-Spot.

http://img.photobucket.com/albums/v233/urthling/75.jpg
BTW- This photo is from Toshi's website

[xy9ine]

a guy built a shaft drive for his dh bike a couple years ago. looks nice & clean.

shaft (http://leelikesbikes.com/Stories/110304b/)

[Alexey]

very cool

[xy9ine]

another interesting chain-eliminating concept: there's a guy building a hydraulic drivetrain that uses a pump @ the crank & some kind of drive mechanism @ the hub - just a hydraulic line connecting them. here's a (long) thread on pb:

hydro (http://vpfree.pinkbike.com/bb/viewtopic.php?t=72765&postdays=0&postorder=asc&start=0)

here's the pump mechanism:


http://www.pinkbike.com/photo/380/pbpic380555.jpg

[Dean W]

Very interesting.

This one is sweet.......if it works as they claim.

http://www.powerengine.com/aitx001hydbiksum.htm

[Oldfart]

Lot's of gear friction in a shaft drive. Plus the bike it's on in the picture is not a heavy duty mountainbike. I think you'd need a much beefier one for serious riding. And where to the gears go? I have this little coffee table book at home with pictures of bicycles through the ages. Shaft drives are not new, in fact many of the bikes are WW1 and 2 bikes with gun mounts and suspension at both ends.

For all its problems, the roller chain driven derailleur shifted system is very efficient energy wise and works better than anything else so far. That Honda bike might be pretty good though, but no one knows much about its workings other than Honda. Rholoff's address some issues but they are complex and increase the friction in the system despite what Rholoff say.

I've read Rholoff claim less energy loss from friction than a derailleur system. I call shenanigans on that because both systems are gear and chain driven so the difference is two pulley wheels versus a myriad of of little gears.

[xy9ine]

Originally posted by Oldfart
That Honda bike might be pretty good though, but no one knows much about its workings other than Honda.


as it turns out the honda tranny is really pretty simple - essentially a deraileur & cassette in a box.

http://www.honda.co.jp/HRC/closeup/images/06/closeup06_03.jpg

[psyloman]

I actually have a shaft drive bike at work atm sililar design to the one in the 1st pic, its not for serious riding but nice for around town seems very effictive and also its set up with a SRAM S7 7 speed internal geared hub that seems to give a nice range aswell

[thewwkayaker]

Yes the NEW Honda gearbox is very simple. That idea has also been done (under different patents) by a Dutch group that was recently bought by Hayes. Expect to see in a few years a Hayes gearbox on some future DH/FR bikes. This is the best of all worlds.

[xy9ine]

thats the petespeed tranny that was developed on the b1 dh bike - very similar to the honda. should be interesting to see how / when these systems hit production. i guess the trick lies in standardization of the systems to a point - so they can be cranked out in volume at a reasonable cost.