Oh I thought you had 220mm in the front I'm thinking of trying 220mm rotor on the front since I prefer really powerful front brake. It might make the front brake too powerful but it's not a high cost just to test it out on the rear I don't think there is a scenario where bigger than 180mm rotor would be needed with these brakes.I am using a 203mm rotor on the front and 180mm on the rear. I had the same problem with adapters on both of my bikes and ended up with the Shimano adapters after returning a couple that didn't work. I didn't have to shim at all on my LCE930 but I did have to shim a bit on my other bike and my wife's bike.
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I am using Bucklos rotors on the front and rear. So far no issues with the rotors or brakes. I am about 3/4 through my first set of pads.
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