Custom E-bike - What should I consider?

[Art Deco]

Yeah, hydraulics were on my "must have" list. Mostly B/C the wife has arthritis in her hands and rides too fast. It's Something that any bike shop can service, as well.

 

[Sierratim]

I've used both and the bottom line is they both work. There's no point in any attempt to totally discount one or the other. The fact the mechanicals are less expensive, and aren't offered on high end bikes, doesn't mean they can't/won't stop an e-bike. That isn't true at all. In defense of the hydraulics, IMHO, they require less effort for equal stoping power (all else being equal).

Just to be clear, I'm not saying that mech disc brakes don't work on ebikes. I'm saying specifically I wouldn't recommend them for an ebike due to the added weight. I do believe you are exactly right that hydraulic disc brakes require less effort (hand pressure) for equal stopping power, among other note worthy advantages.

Hydraulics do have a disadvantage in that any fluid leak generally requires some shop time (home or LBS) where as mech disc brakes can generally be field repaired (if you are prepared for this). This is a consideration for long distance adventure riders where some report preferring high end mech disc brakes to hydraulics for the practicality of field repairs, though even they acknowledge the underlying performance advantages of hydraulic brakes.

How big an issue are leaks in hydraulic brake systems? I can't find any data but my MTB enthusiast sons tell me that neither of them has had a leak in years. The oldest of their (many) bikes is ~5 years old with over 8,000 miles on it. Multiple pad replacements, but no fluid issues. One son is a mech engineer for a cycling component manufacturer. He tells me that this level of reliability is fairly common in modern brand name hydraulic disc brake systems.

Like my sons, I'm all in. YRMV.