Electric gear shifting - simpler, cheaper, better.

proto

Just idling away at my my desk, thinking of bikes and stuff. I'm rather taken with the new electric Dura Ace Di2 stuff, works brilliantly. I suspect the new Campag stuff will be equally good. However the cost is eyewatering. I spend loads on bikes and even for me they are out of my reach.

So, is there a cheap option I ask myself. The Shimano stuff uses servo motors in both of the mechs, but lets be fair, cable/spring operated mechs work perfectly well, but have the disadvantage of the rider having to fiddle about with levers and paddles to effect a gear change, which takes place by the gear cable being changed in length.

Would it be possible to have a mechanism, say a motorised eccentric roller which does the cable length changing. Still use existing front and rear mechs, but the shifting is done by pressing a button, which operates a stepper motor, which rotates the eccentric roller, which tensions the cable, which changes the gear.

Only new parts needed are new simpler shifters, basically brake levers with two switches built in, and a motorised roller system. Cheaper, more reliable.

Whadda you reckon .Good idea? Should I patent it.

Smokin Joe

Possibly.

But maybe the power needed to operate a cable (which has to overcome friction in the housings and cable guides) would be greater than to simply move the mech on it's own, leading to shortened battery life?

ChrisSA

I think DI2 uses stepper motors too.

I don't see any major problems with what you describe, though the cam would need to be quite big to change through 10 gears, or even the front mech. You've got prior art by this post now.

Is DI2 really servo driven? That must be a huge battery drain. Saves on springs etc though.

Berk Bonebonce

Electronic shifting is old hat. Mavic done it with Mektronic about a decade ago. Cables offer reliability.

proto

Thinking about the roller to tension the cable, it only has to re-create the action of the cable tensioner in existing levers, effectively motorised ergo/STis. The mechanism can be anywhere, it doesn't have to be in the lever.So, stick them under the BB or under the down tube>

giant_man

Berk Bonebonce wrote:

Electronic shifting is old hat. Mavic done it with Mektronic about a decade ago. Cables offer reliability.

Didn't sell very well though did it mate? Can't have been that good not to bring to market. Shimano have done very well and Campagnolo wil do even better with any luck.

Smokin Joe

Mavic's R&D budget was probably smaller than Shimano's coffee bill. The reliability issues that plagued them should easily be sorted by Campag and Shimano.

peter101cycle

proto wrote:

Would it be possible to have a mechanism, say a motorised eccentric roller which does the cable length changing. Still use existing front and rear mechs, but the shifting is done by pressing a button, which operates a stepper motor, which rotates the eccentric roller, which tensions the cable, which changes the gear.

Only new parts needed are new simpler shifters, basically brake levers with two switches built in, and a motorised roller system. Cheaper, more reliable.

Whadda you reckon .Good idea? Should I patent it.

That is the best idea I have heard on here.....tell you what, I will call it my idea and patent it myself!

Only joking by the way but my wife works in Patents......

The very fact that you have disclosed the idea on this forum, means that you be very unlikely to be able to patent the idea. If you have great ideas people, you tell nobody.
:shock:

ChrisSA

peter101cycle wrote:

proto wrote:

Only joking by the way but my wife works in Patents......

The very fact that you have disclosed the idea on this forum, means that you be very unlikely to be able to patent the idea. If you have great ideas people, you tell nobody.
:shock:

Or wait for someone else to patent it, show them prior art then charge them to license your idea!