http://www.ginko.de/user/thomaskretschmer/website.htm
It also applies to unicycles IMHO.
“Sorry don’t anything more about it”, Oz http://www.liegerad.com
Geared hubs are for sale here:
http://www.schlumpf.ch/speed/speeddrivee.html
Also, a long thread on this subject can be found here:
http://www.unicyclist.com/forums/showthread.php?s=&threadid=14288&highlight=geared+hub
Nice to see people thinking about this…synergy might find a creative answers to making this practical
Pricepoint is the big issue (otherwise, we would all have a Speeddrive, I suppose). If it could be produced at a reasonable weight for less than half a grand…
Christopher LeFay
I have seen this site before. This is a very elegant, multigeared, epicyclic hub design. I don’t think Kretschmer has built the chainless version yet so this hub is probably still in the design phase.
The Schlumpf version is for a bicycle chainring drive. It could probably be used directly in a giraffe type chain driven unicycle. It would require extensive modifications to be used with a hub like the Kretschmer version.
On Mon, 26 Nov 2001 19:05:13 +0000 (UTC), harper
<forum.member@unicyclist.com> wrote:
>I have seen this site before. This is a very elegant, multigeared,
>epicyclic hub design. I don’t think Kretschmer has built the chainless
>version yet so this hub is probably still in the design phase.
Actually according to the German HPV mailing list there is somebody riding
a recumbent with Kretschmer hub, and not Thomas Kretschmer himself. So
there should be at least two working prototypes around…
Oz
Speeddrive doesn’t work on unicycles / fixed bikes because it can’t take
much more back pressure than the amount created by a freewheel hub. I
think its something to do with the shape of the gears being optimised for
shifting smoothly between the two gears by making them only work properly
when pedalling forwards. The big difficulty with a multi-gear planetary
hub is always going to be shifting under load without jumping too much.
Joe
“harper” <forum.member@unicyclist.com> wrote in message
news:9tu4c8$mmr$1@laurel.tc.umn.edu…
> The Schlumpf version is for a bicycle chainring drive. It could probably
> be used directly in a giraffe type chain driven unicycle. It would
> require extensive modifications to be used with a hub like the
> Kretschmer version.
>
>
>
>
> –
> harper Posted via the Unicyclist Community -
> http://unicyclist.com/forums