Misaligned caliper
#1
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Misaligned caliper
I have a bike with Mt520 brakes and Rt10 rotors. It came originally with MT400 brakes that worked well.
However I noticed that the rear caliper sits a bit high relative to the disc and there's a small part of the pads that overhang the rotor.
This happened with the original frame the bike came with, but the frame was replaced in warranty for non related issues and, with the new frame, it sits exactly at the same position.
The caliper is mounted without any kind of adapters or spacers, directly on the post mounts of the frame. The front brake, which has a 180mm adapter, seems OK but only by a hair.
In theory the rt10 rotors are wide rotors while the mt520 brakes are narrow type, but according to shimano they should be compatible.
Since the rt10 are resin only, I'd like to upgrade them anyway, but before doing that, I'd like to make sure everything fits properly.
Any idea of what could be happening? Is it possible that wide rotors have a slightly smaller diameter than narrow ones?
However I noticed that the rear caliper sits a bit high relative to the disc and there's a small part of the pads that overhang the rotor.
This happened with the original frame the bike came with, but the frame was replaced in warranty for non related issues and, with the new frame, it sits exactly at the same position.
The caliper is mounted without any kind of adapters or spacers, directly on the post mounts of the frame. The front brake, which has a 180mm adapter, seems OK but only by a hair.
In theory the rt10 rotors are wide rotors while the mt520 brakes are narrow type, but according to shimano they should be compatible.
Since the rt10 are resin only, I'd like to upgrade them anyway, but before doing that, I'd like to make sure everything fits properly.
Any idea of what could be happening? Is it possible that wide rotors have a slightly smaller diameter than narrow ones?
#2
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Is it possible that wide rotors have a slightly smaller diameter than narrow ones?
Post some photos.
#3
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Here are some pics. As you can see, the top of the pad has a strip of less than 1mm which is not worn because it's not contacting the rotor.
The thing is I can't do anything except try another rotor, since there are no spacers or anything between the frame and the caliper. It's just the caliper bolted directly on the mounts.
Last edited by Amt0571; 10-29-20 at 12:28 AM.
#5
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Probably. Compared to the front rotor it seems the caliper is also slightly inclined relative to the rotor. It's difficult to see in the picture, but the part of the pad that is at front is not worn, while the part at the back contacts the rotor fully.
In any case, I suppose milling the posts will be an issue in case I need to use the warranty. I'd do it if it was an old frame, but I'm not willing to do it on a new one.
In any case, I suppose milling the posts will be an issue in case I need to use the warranty. I'd do it if it was an old frame, but I'm not willing to do it on a new one.
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Contact the dealer/shop if it's still under warranty?
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^^ What did they say about your concern with the brakes?
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mill the mounting surface on the caliper.
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It may not even be the machining on the caliper mount. Perhaps the brake pad isn't seating fully in the caliper. Pull the brake pad from the front, and try it in the rear. Make sure it's shoved all the way into the caliper.
I'd try all of the above before taking more drastic measures like milling down some part.
If the problem IS with the frame - which is unlikely - you need a shop with the correct tool to face the brake mount.
Last edited by Koyote; 10-29-20 at 07:01 PM.
#13
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That suggests the problem may be with the caliper. Have you got another caliper that you can try, just for comparison?
It may not even be the machining on the caliper mount. Perhaps the brake pad isn't seating fully in the caliper. Pull the brake pad from the front, and try it in the rear. Make sure it's shoved all the way into the caliper.
I'd try all of the above before taking more drastic measures like milling down some part.
If the problem IS with the frame - which is unlikely - you need a shop with the correct tool to face the brake mount.
It may not even be the machining on the caliper mount. Perhaps the brake pad isn't seating fully in the caliper. Pull the brake pad from the front, and try it in the rear. Make sure it's shoved all the way into the caliper.
I'd try all of the above before taking more drastic measures like milling down some part.
If the problem IS with the frame - which is unlikely - you need a shop with the correct tool to face the brake mount.
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#17
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You didn't understand me. I already did that. Both work well at the front. Both have the same issue at the rear.
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But that does make it seem like more of a frame issue. Rear mount might even just have a very thick coating of paint, and need to be faced.
#19
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If that's what you were trying to convey in post #13 , your syntax needs some work.
But that does make it seem like more of a frame issue. Rear mount might even just have a very thick coating of paint, and need to be faced.
But that does make it seem like more of a frame issue. Rear mount might even just have a very thick coating of paint, and need to be faced.
I've just checked and the rear mount has no paint on the part where the caliper sits. As I said, the frame was replaced in warranty and previous frame had the same issue... Canyon are not known for their tight manufacturing tolerances, but the same issue on both frames seems strange to me.