rotor heat, color
hi,
Took a new 2012 Specialized Epic Comp 29 up and down my training hill a few times. At the time was unaware of bedding in pads. Didn't have to do it with my Orbea with Avid mechanical discs, which I thought worked very well. After a few runs up and down my hill, 5.25 mile up 2,500' gain, my rear Avid Elixir started screaming. Rotor was dark blue. Maybe went up, then down, about 6 - 8 times. Caliper aligned well, pads not rubbing on rotor, rear wheel spins freely.
Front Avid Elixir 160mm was working just fine. Both fr and r were stopping very well, much better than mechanical cable Avids.
Bought new aluminum backed pads and new 160 rear rotor. Read the many articles on bedding and took my time trying to do it carefully.
Rotor turned blue same amount of time and howled so people could hear me a mile away, just like first set.
Front still just fine. Fr and r still have great stopping power.
People, mechanics, said to feather rear brake, use more front, pump rear ...
Sorry, but I'm used to off road motorcycles and have ridden mountain bikes for a living so can use brakes to their limits, to where the front wheel starts to lock up. Am using the front brake up to the point of locking up, then lighten up for corners. Using rear as much as I can to stop on sustained steep downhills. If I need to feather or pump rear I feel the brake is not working up to what I'm demanding. If I bought larger front rotor will still be using rear just as much; to the point just short of wheel lockup.
Bought rear 2012 XT 160mm entire brake setup, w. ICE technology. Brake levers all the way back to caliper, pads w. cooling fins, rotor(3 layer, steel/al/steel). Bike is a month old at this point. All I'm riding is up and down training hill. Getting ready for event.
Rear XT brakes were great. Took special effort to bed in pads. Worked very very well. Went up and down my training hill about 8 times. All good.
Just did the Vision Quest. Has some long ups and long downhills. After about 50 miles and 11,000' gain my rear XT started talking. Loudly. But not as bad as Avid Elixir got to. Rotor is discolored but not as dark blue as the 2 Avid rear.
So it took longer for the XT's to get to the point of hot/noise.
May try XT 180mm rear, more for heat dissipation rather than stopping power, but if I don't need to pull the lever as much, because the 180 will be a bit more powerful, then they will run cooler. I know it is unusual to have larger rear than fr rotor but possibly sometimes you need to think outside of the box. Thinking the 29er, slightly longer wheel base, more weight over rear tire, is simply able to use and demand more rear brake.
Thanks
Steve
Last edited by sfenn99; 04-24-12 at 05:31 PM.