Originally Posted by
cxwrench
I've said it time and time again...it's NOT THE CABLES that really need replacing (unless they're fatiguing and fraying inside the shifter) it's the HOUSING wear that causes deterioration in shifting performance. If you think it's the cables that are the problem and you just replace them it shows just how little you know. If you ride 4-5 days a week you would be doing yourself a favor if you replaced both on an annual basis.
Not well designed? How much better do you think you could do? Let's hear it.
Ok. I'll bite. Housing wear? There is an inner sheath, the steel structural linear strands of the housing, and the outer case, which on most of the cables I have seen looks to be vinyl but I haven't actually checked.
As a system, the inner sheath is there to limit the friction. The steel structural stranded linear housing is aligned parallel to the direction of pull and should not wear, but the outer case could stretch which would definitely degrade shifting.
I know that Jagwire sells housing with a kevlar braid covering the stranded structural part of the housing.That should reduce the degradation of the housing. There are also housings made of multiple segments like the Nokon housing.
So I really don't need to design a better product. It looks to be an off the shelf item. Albeit a costly one. I put Ekar on my commuter / touring / gravel bike. If shifting performance goes down after a year, I will probably start with the braided covered Jagwire housing. The Nokon housing looks nice but it is expensive.
My solution to control cable issues has mostly been to use some form of linear electronic motion system. Linear motors or a rotary to linear gearbox. I think that is what is inside an EPS rear derailleur.
I ride 6-7 days a week in the summer, and an EPS group set doesn't have any issues, and since the cables don't flex all that much, fatigue of the power and control cables is not an issue.
I'm likely going to put an electronic motion rear derailleur on the tandem. Probably a SRAM, since the tandem is the only place I have noticed poor shifter performance.