Hydraulic Rear Der?

Okay…tell me why hydraulic rear der is a bad idea…

Seems to me that it is a system that is proven in years of automotive and aviation uses. The best I can tell is that the hoses and fluid does not have any weight issues as compared to full housing that is now semi-common on bikes (yeesh). I would think that a small reservoir in the lever and small one at the Der would provide the capacity for the fluid (that would never stretch).

I would imagine that fluid control for indexing would still be done at the shift lever. The housing and fittings could take 90 and 180 degree bends with out the extra housing needed on cable systems. Would not need to worry about water – road grime – salt getting into the seal hydraulic lines.

Please…tell me the thousands of reasons this is just a dumb idea.

Chip

A nick in the line and fluid leakage could be disasterous if you plan to change gears.

Unless you use a lightweight braided housing

Seems the MTN bikes dont have issues with nicks - for the brakes, I would much rather lack shifting over stopping.

Sometimes mountain bikes do have issues with the fluid being consistent. e.g. fluid expands with temperature, and in a brake system this isn’t such a bad thing but it would be enough to throw your indexing right off. Disc brakes are also constantly going mushy from air in the lines, from leaks, or from super-heated hydraulic fluid. Shifting needs to be precise, and though disc brakes work well, modulation (precision) isn’t exactly their best characteristic.

Hello Record10Carbon,

I had a Mavic electric shifter several years ago and it worked OK, very smooth and aero. The potential problem was maintenance at some place like Brazil, where you could get Shimano parts, but not Mavic.

Cheers,

Neal

Eeckhout wins on Campagnolo Electric

By Tim Maloney and John Stevenson Nico Eeckhout’s Eddy Merckx
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike1tn.jpg Campagnolo Electric rear derailleur
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike4tn.jpg Campagnolo Electric transmission
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike3tn.jpg Campagnolo Electric front derailleur
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike7tn.jpg Campagnolo Electric rear derailleur
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike5tn.jpg The Electric’s control unit
Photo ©: Luc Claessen http://www.cyclingnews.com/photos/2005/tech/news/apr05/bike8tn.jpg

Two years ago, CN editor Jeff Jones spotted a prototype version of Campagnolo’s electric component group from the Cyclingnews blimp at the E3 Prijs Vlaanderen in Harelbeke, Belgium. Although there is no commercial launch slated, Campagnolo has continued to test and develop this technology and one of the teams that that has an Electric group is Chocolade Jacques. In last Wednesday’s 60th edition of the Dwars door Vlaanderen, experienced Nico Eeckhout outsprinted Discovery Channel’s Roger Hammond for the win, and in doing so made cycling history. Why? Although Chris Boardman won the 1994 Tour de France Prologue in Lille, France riding Mavic’s ZAP electric rear derailleur, Eeckhout’s win was the first ever for an electric shifter in a point to point pro road race.

The Campagnolo group is far more sophisticated and evolved than either of Mavic’s groups, with a fully electric front derailleur as well as rear mech though our sources at Campagnolo recently told Cyclingnews that there are still no plans to bring the Electric group to market.

Given Campagnolo’s strengths as a component maker, it’s not very surprising that the company is taking a slow-and-steady approach to the development of the Electric group. As well as Mavic’s two failed attempts at a switch-controlled shifting system, the Browning mountain bike transmission of the late 80s provides a great example of how well something can work in the lab but still be a disaster when you take it out and ride it. But anything that has ‘Campagnolo’ etched into it has to be reliable - that is, after all, what Vicenza is known for.

Making reliable electrical devices for bikes isn’t trivial - consider how much more reliable brakes and shifting systems are than bike computers and lights, for example. The problems are multiple, but they boil down to maintaining electrical connections in a hostile environment. Even the stiffest bikes are flexible, which plays havoc with electrical connections; and there’s the ever-present problem of water.

Bike equipment also has to be light in weight, which usually means the tricks used to make motor vehicle electrical systems reliable just aren’t available: you can’t use thick wires and hulking great plugs with rubber seals on bikes, they’re just too heavy.

Will Electric ever ship? We hope so - the notion of pressing a button and having the solenoids and electronics do everything else for you has merit. Whatever happens it’s encouraging to see Campagnolo apparently learning from the mistakes of others and not rushing to market with equipment that works fine on a test bench but not in the real world.

I am not going to badmouth the idea, snce someone has already done it,

read all about it here

http://weightweenies.starbike.com/articles.php?ID=28
http://www.cyclingnews.com/tech/2006/shows/eurobike06/?id=results/eurobike067

actually, there is one issue I am aware of with hydraulics, “Creep”
most hydraulic pistons under a load will not stay still.
there is almost always a small amount of fliud that seeps past the piston seal or out the gland seal, upsetting the fluid balance in the cylinder, and allowing the piston to move.
I am very interested in any possible solutions to this.