Originally Posted by
Joe Perez
As someone who has owned several bikes with both, I do have to agree that the adjustment of rim brakes is much more "fiddly."
With mechanical disc brakes, you basically just have one screw to turn, which moves the fixed pad in and out, and then a second adjustment for the moving pad which is similar to any other cable-operated brake. That's it.
With rim brakes, you have those same adjustments, plus you have to set the spring-centering with two more screws, plus you have to set the alignment of both pads in four axis (height, rotation, toe and camber), all of which are simultaneously locked and released with a single screw. I find this to be much more difficult and time-consuming than just setting the in-out position of a disc pad to compensate for wear.
Hold on a second. If we are talking about simply adjusting for pad wear, rim brakes are no more fiddly than discs. To adjust for wear (only) on rim brakes, you simply have to take in the slack on the cable. You shouldn't have to mess with the pad angle, the spring balance, nor adjust the height. Pad wear on a mechanical disc pad may require taking up slack on the cable, moving the moving pad and/or moving the fixed pad.
If you are
setting up a rim brake there are a lot of steps to the set up but there are equally as many steps to setting up a hub mounted disc...up to and including truing the brake track. The rim brake is a little more forgiving in that the wheel doesn't have to be hypertrue to be useable while even a little wobble with a hub mounted disc leads may lead to problems.
Originally Posted by
Joe Perez
Discs are not significantly more expensive than rim brakes. This might have been true at one time, but the Chinese have gotten on-board now. If you add in the fact that disc brakes do not abrade the rim and will tolerate some runout, they can actually wind up being cheaper over time.
Discs are not universally noisier than rim brakes. While there may be some rim-brake compounds that are significantly quieter than some disc-brake compounds, I can say quite affirmatively that the rim brakes on my current Schwinn (SwissStop green front, OEM black rubber rear) are much louder than the Tektro Novelas on my Giant Revel 1 (the e-bike) under hard braking.
And far from being more hassle, discs, in my experience, are significantly LESS hassle than rim brakes. I have literally never done anything at all to the discs on my e-bike (which is very heavy and runs at 25-30 MPH) other than occasionally nudge the pads in and replace them once a year or so.
As for weight, well, I have to admit that I've never weighed a complete disc setup and a complete rim setup. If a difference does exist, then we're literally talking about a few ounces. That might matter to an olympic-level cyclist, but to even mention it in the context of a commuter is ludicrous. I ride steel-framed bikes with fenders and cargo baskets and carry a Kryptonite lock that weighs a couple of pounds. To argue that disc brakes are worse that rim brakes in this context because of their weight makes me thing you're just trying to be deliberately contrarian. I race in Cat-6, not Cat-1.
Cheap discs are worse than cheap rim brakes. They perform very poorly and are almost unadjustable. I've had lots of opportunity to work on both and I can usually get even the cheapest of rim brakes to do the job but the same isn't true for cheap discs.
Rim wear isn't that much of an issue either. I see bikes every Saturday (I'm shop lead at my local co-op) that have 30+ year old wheels on them and seldom see a bike with worn out rims. It happens...I've worn out 3 rims in 30+ years and ~100,000 miles of riding...but it's not as big an issue as many people would have you believe. If you drag your brakes all the time, you'll wear out a rim but if you brake effectively, it's not that much of an issue.
Finally, hub mounted disc brakes will tolerate some runout at the rim but they won't tolerate any more run out at the braking surface than rim brakes. In fact they will tolerate less because there isn't much gap between the pads and the rotor. A bend in the rotor of less than a millimeter will result in brake rub or even complete stoppage. Neither system is perfect but then neither system is vastly better than the other.