Lost in the noise of the 105 Di2 hoopla came this announcement today…
Has anyone had issue with disc rotor running on 9200/8100 yet?
Because I have not.
I have XTRs on the TT bike, Galfer on the aero, and Carbon Ti on the Climber. High speeds, climbing, sprinting, descending Alpe d‘Huez at Full send… besides a few minor ticks, I’ve never heard anything from them.
I run campy rotors w/ swiss stop pads in my Dura Ace discs and they work perfectly. I’ve yet to hear it rub and I have recently tested 50mph to 5 as quick as possible. I weigh 100kg’s. No rub. YMMV.
I’ve only done a few rides on 9200 but so far I’ve not heard a noise from it. Looks as if Shim have got it nailed now
Did the old ones have rubbing problems? I’ve descended Mt. Evans and Pikes Peak(along with other large CO descents) on my GRX calipers and stock pads with the old Ultegra rotors and haven’t had any issues. Hell, the original pads have almost 16k miles on them!(they are at the end of their life though, New ones going in soon)
Yes, for some users. The original road rotors, coupled with the older calipers (10% narrower pad spacing compared to the latest models) can lead to rotor temporary warp/deformation that leads to drag and noise.
This is true even if the brake rotor is properly aligned when the rotor is cool. People can experience enough heat to change the rotor straightness enough to cause minor problems. Even I at 145lbs have experienced it on my Emonda Disc despite many ours of tuning the caliper alignment and rotor trueness.
The “hack” that Shim and others swapped to for a while was using the MTB rotors instead of the Road ones for road applications. Those MTB ones handle the heat better without the same warp issues.
Did the GRX calipers gain the extra pad clearance? or was it just the new 12 speed stuff?
Great question, that I don’t remember to answer. I’d have to look that up.
Ive been running xtr rotors for 6mo or so and seems to have done the trick. The ultegra rotors needed to be true’d more often than Id like. That said, im a bit bigger guy at around 200#, so ill give them some mechanical sympathy
Is this issue something that has been existing for SRAM as well? Just about to change to a new TT bike with SRAM disc and the very last thing I want is rubbing.
Aggressive descender. I descend 10-15,000’ a week, weigh 160lbs, had 105 rotors. I warped the front rotor almost weekly. It would so hot they’d start screaming by the end of a descent. It would drive me crazy having to straighten it each week. Eventually upgraded to Ultegra and have only had to do it once. I’m not braking as hard though, mostly because I had a pretty bad crash earlier this year
My road bikes (both, Shimano Ultegra/105 mix and now Force eTap AXS) have had no problems. Only on a super long descent (600+ m of elevation in one go with lots of hairpins and some traffic, i. e. lots of braking) did the Force brakes start to ting-ting for a few seconds literally until they had cooled off. But even then it wasn’t very loud. On my previous Shimano I could get the brakes to start rubbing on all-out, out-of-the-saddle sprints. My suspicion is that the hubs weren’t stiff enough. (The hubs are actually a culprit that few people seem to talk about.)
In my experience, 105 rotors are, hmmm, not great. But Shimano’s IceTech rotors (Ultegra/XT and up) are, and I recommend upgrading them. Also, get the largest rotors that fit your bike (160 mm front and rear should fit). In the past, Shimano had separate road and mountain bike rotors. Their mountain bike rotors were coping with the additional heat much better than their road siblings — and they are fully compatible. Nowadays, they are one-and-the-same it seems. (At least the 180 mm rotors I ordered for my mountain bike say XT/Ultegra on the box.)
Yup. Immediately went to ultegra. And only 160. I need all the stopping power I can get.