Author Topic: Hydraulic shifter. Is there such a thing ?  (Read 3398 times)

MilitantGraham

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Hydraulic shifter. Is there such a thing ?
« on: December 07, 2009, 02:05:09 PM »
I've had nothing but trouble with gear cables on both my Rohloff bikes.
I've tried normal cables with Middleburn cable oilers, Flying Snake, Gore and Nokon. They all seize. The liners or coatings all wear through.

I've heard of hydraulic and electronic shifters for derailleurs. Does anyone make them for Rohloff ?

brummie

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Re: Hydraulic shifter. Is there such a thing ?
« Reply #1 on: December 07, 2009, 03:11:43 PM »
Have you tried running gear inner cables with (shimano) BRAKE outer cable ?
 

Andre Jute

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Re: Hydraulic shifter. Is there such a thing ?
« Reply #2 on: December 07, 2009, 08:06:22 PM »
I've heard of hydraulic and electronic shifters for derailleurs. Does anyone make them for Rohloff ?

I have a hub gear bike with electronic shifting. See it here:
 http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html 
by checking out the Trek Cyber Nexus Smover.

That's a special adaptation of the Shimano Nexus 8 speed box, with a stepper motor wrapping around the end of the axle.

I thought of electrifying the Rohloff gearbox but the obvious way would be with a reversible stepper motor, or two stepper motors, which could be positioned"

1) on the handlebars to operate the standard cables

2) on the seatstay to operate the internal cables of the Rohloff box from, say, the standard break near the cantis

3) on the lefthand chainstay to operate the Rohloff external klickbox via short cables

4) on the nut over which the external klickbox otherwise fits, replacing the cabled mechanical klickbox, in short a version of what Shimano already has in the hub gear version of the Cyber Nexus

Seems to me that solution 1 while easy to implement would just give you the same old problems, solutions 2 and 3 might be more difficult to implement without soldering on brackets but would solve your problems handily, and solution 4 is optimum but might require a spot of engineering to make the reversible stepper motor fit over the actual gearchanging nut.

Stepper motors are dirt cheap and no touring bike should be without a hub dynamo, which can power the stepper motor.

HTH.

Hobbes

MilitantGraham

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Re: Hydraulic shifter. Is there such a thing ?
« Reply #3 on: December 09, 2009, 10:48:17 AM »
Quote
...no touring bike should be without a hub dynamo...
It's not a touring bike, it's a racing mountain bike.  ;)

I've had the bike upside down for  acouple of days now, gradually dripping oil down the cables through the open clickbox, like this...



It's not ideal, but it''s the best I can do at the moment.

I did wonder about using some sort of radio control model solenoids with a ratchet to push and pull the clickbox directly, powered by a small Li-Po battery, or maybe two hydraulic brake levers mounted on the bars with two slave cylinders on the clickbox.
I haven't really looked in to the practicality of any of this yet, I was hoping someone else had already done it so I could copy them.

stutho

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Re: Hydraulic shifter. Is there such a thing ?
« Reply #4 on: December 10, 2009, 02:27:34 PM »
MG,
I know you use a full sup frame,  do you use full cables runs? 

My bike has a very different  mission to yours - nearly all on road.  The original cables failed very early on I think it was at about 4000miles / 1 year.  I then switched to XTR brake outer combined with a Teflon coated gear  inner (I think this was a Transfil, but I may be wrong). since then I have had 3 years / 12,000miles of trouble free.
« Last Edit: December 10, 2009, 03:19:48 PM by stutho »