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What size front rotor for disc brake
NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.
I was wondering what size front brake rotor most people were using for typical perth hills riding. Places like kalamunda and Forsyth's Mill.
160 or 180? Is there any benefit in upsizing to a 180.
I am getting new wheels and need to buy centrelock rotors. Not sure whether to go 160 or 180.
Any recommendations would be appreciated.
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But I'm 68kg, bike is 10.5kg, add 4kg for tools water etc., on a 29r and I'm not heavy on brakes.
Thinking of going to a 140 on rear as on 20% downhills its easy to lock the rear.
I run 180 front and 160 back on my trance with xt brakes. Perfect combo
I've always favored as big as you can get on the front. Much better modulation and leverage. The bigger discs heat up less and cool down faster than the smaller discs. Rough gestimate every 20mm would equal about 15% better braking leverage. Not all forks can take them and I guess there is the weight penalty if you worry about that sort of thing.
I'm not too worried about weight on the bike. I weigh a out 75 and the bike probably around 14kg maybe a little lighter.
I will definately run 160 at the rear. That is all I need. But the 180 at front might be better than my existing 160.
I did hear that a larger disc can make it easier to skid the brakes. But I'm probably unlikely to skid the front. Might skid the back easy if I went to 180??
You'll skid the rear with any size if you try, the larger at the front will pull you up quicker or stand it on it's nose.
Im ~85kg total weight, on a long travel 26.
160mm on the rear, which is the smallest I can go.
180mm on the front.
Have thought about going 203/180, but its not that steep here, and I'm not that fast.
I also agree bigger is better. I want effortless 1 finger braking with the best modulation. The less I have to crank on the brakes the more I can keep my hands light and loose. Doesn't help if I'm clenching my hands when I need it least.
Brakes and pads will also make just as big a difference. My old juicy 5s (160/140) were rubbish regardless of pad choice. An SLX equipped bike I test rode (180/160) were totally underwhelming. The resin finned pads on my outgoing XT and current XTR (both 180/160) feel great. Tons of 1 finger power and easy modulation.
True true MrMez. Good point. Gotta compare apples with apples
If anything a larger rotor should give you better power modulation on any half decent brake because you've got a wider range of power available. Plus if your bike is over 12kg anyway there's no serious weight penalty anyway.
Just make sure your brand of brake does actually use 160 and by extension 180 rotors with a 20mm caliper adaptor. Some use 183 for example, or at least they used to. There can also be a difference in the thickness of the disc. Most use 160 and 180 though which makes rotors from other brands an option as well, I've used Hope and Shimano ones interchangeably.