Bike Forums - View Single Post - Are disc brakes the new clipless?

05-17-16 | 06:59 AM

#226

Wheever

Senior Member

Joined: Jun 2014

Posts: 1,140

Likes: 9

From: Stamford, CT; Pownal, VT

Bikes: 2015 Trek Domane 6 disk, 2016 Scott Big Jon Fat Bike

Quote:

Originally Posted by nashvillebill

Yes, I have ridden disc brakes, they were certainly very good. I'm not knocking them.

What may be "missing" ....well not really "missing" but rather "unaccounted for" .... Often when comparing new stuff to old stuff, the old stuff isn't in the greatest of conditions. So if the old rim brakes have ancient, dried-out, hard-as-rocks pads, with old stretched cables that haven't been lubed in years, riding on dirty/greasy rims, and is out of adjustment, while the new disc brakes have fresh soft pads on clean discs, then gee the new stuff will naturally seem to be a vast improvement. Conversely, if a brand-new rim brake system, properly set up, is compared to a disc brake setup that has water-saturated brake fluid, hard pads, and oil-contaminated discs, the rim brake should come out on top as well.

So a true comparison would be two brand new systems, on similar bikes, similar tires, similar brake pads, etc. The hydraulic system will have a slightly different feel probably. But if full tire lock-up is achieved at say 90% of brake lever travel with a brake lever pull of 30 lbs on the rim brake, and the full tire lock-up is also achieved at 90% of brake lever travel on the hydraulic system, then the brake lever pull on the hydraulic must also be 30 lbs. Both systems do the same amount of work, they cannot add any power, merely transfer force at some ratio. Both systems, if properly designed, implemented, and maintained, operate at very high levels of efficiency. That can be a big IF in the case of some rim brake designs, I totally recognize that it's easy to wind up with a poorly adjusted, poorly performing rim brake system.

That doesn't really apply in my situation. I've ridden all sorts of rim brakes for decades, in various states of function. And I've ridden my disc bike when the rear pad was contaminated. Even contaminated and screeching, the disc brake still only operated as badly as a crappy rim brake. I could stop the bike with just the contaminated rear brake. As a matter of fact, the day I tried my first disc bike (a Domane 4.5 that I subsequently bought!) I had been trying all sorts of high-end bikes (which I couldn't afford) including the salesman's personal bike which he races, and the first time I braked hard on the disc bike it blew them all away. I couldn't believe the braking force I could generate with just my index fingers. Would have required a handful of fingers to get that much braking force with rim brakes.

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