Rohloff Lever Shifters

"Tosspot" <[email protected]> wrote in message
news:[email protected]...
> Much as a twist grip lends itself to a Rohloff hub, I'd like to try some
> sort of under bar lever system.
>
> Ideally something like the rapid fire system, but since the indexer is in
> the hub this is obviously not on, however, there must be a way using
> friction shifters.
>
> Anyone got any ideas?

In a derailleur system, the shift cable pulls the shifter parallelogram
one direction. When the cable is slackened a spring in the
derailleur pulls the parallelogram back the other way.

Rohloff shift cables work entirely differently. There are two cables.
One cable pulls one direction and the other pulls the other direction.
Think of a cable wrapped around a pulley - you pull on one end of
the cable and simultaneously let out the other end of the cable
to move the pulley one direction and reverse the process to move
the pulley the other direction.

Shifters for derailleurs only need to pull or slacken one cable.
A Rohloff shifter must simultaneously pull on one cable while
letting out slack in the other cable. You won't be able to do this
with any shifter designed for a derailleur. You will have to use
the one supplied by Rohloff or design and machine one entirely
on your own.

BobT

BobT wrote:
<snip>
> Shifters for derailleurs only need to pull or slacken one cable.
> A Rohloff shifter must simultaneously pull on one cable while
> letting out slack in the other cable. You won't be able to do this
> with any shifter designed for a derailleur.
<snip>

Not quite correct. The *original* Shimano Positron system used a dual
cable system, similar in concept to the Rohloff shifter, to activate an
indexed rear derailleur. These were made in the mid-'70's and were rare
back then, so finding them now will be next to impossible. I did find a
twist-grip shifter for this system on Ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
but that's not what the OP is looking for.

Jeff

JeffWills wrote:
> BobT wrote:
> <snip>
> > Shifters for derailleurs only need to pull or slacken one cable.
> > A Rohloff shifter must simultaneously pull on one cable while
> > letting out slack in the other cable. You won't be able to do this
> > with any shifter designed for a derailleur.
> <snip>
>
> Not quite correct. The *original* Shimano Positron system used a dual
> cable system, similar in concept to the Rohloff shifter, to activate an
> indexed rear derailleur. These were made in the mid-'70's and were rare
> back then, so finding them now will be next to impossible. I did find a
> twist-grip shifter for this system on Ebay:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
> but that's not what the OP is looking for.
>
> Jeff

Are you saying these work for Rohloffs? Was there a lever version?

Nate Knutson wrote:
> JeffWills wrote:
>
>>BobT wrote:
>><snip>
>>
>>>Shifters for derailleurs only need to pull or slacken one cable.
>>>A Rohloff shifter must simultaneously pull on one cable while
>>>letting out slack in the other cable. You won't be able to do this
>>>with any shifter designed for a derailleur.
>>
>><snip>
>>
>>Not quite correct. The *original* Shimano Positron system used a dual
>>cable system, similar in concept to the Rohloff shifter, to activate an
>>indexed rear derailleur. These were made in the mid-'70's and were rare
>>back then, so finding them now will be next to impossible. I did find a
>>twist-grip shifter for this system on Ebay:
>>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
>>but that's not what the OP is looking for.
>>
>>Jeff
>
> Are you saying these work for Rohloffs? Was there a lever version?


Just to recapitualte I'm familiar with the Rohloof, I have two, I've
fitted them myself. What I'm trying to get rid of is the twist shifter
and replace it with something else, ideally something that ressembles a
conventional setup.

On the twist grip front, something I've not tried is motorcycle throttle
assemblies which use a positive push/pull arrangement. I actually have
a spare one so I might try it out of interest.

Somewhere I've seen photos of the twist shifter knob mounted
on a sawed-off bar end. With a setup like that, there might be a way
of jury-rigging a handle onto the knob, and voilá - a (somewhat
oversized) thumby.





You got to be very careful if you don't know where you're going, because you might not get there.


- Yogi Berra

Snortley wrote:
> Somewhere I've seen photos of the twist shifter knob mounted
> on a sawed-off bar end. With a setup like that, there might be a way
> of jury-rigging a handle onto the knob, and voilá - a (somewhat
> oversized) thumby.
>

That's on an Atlantis owned by the unstoppable Mr. Brown:
http://harriscyclery.com/atlantis/atlantis640-01.jpg
as seen on
http://www.sheldonbrown.com/harris/rohloff.html

Jeff