Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Misaligned caliper

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Misaligned caliper

Old 10-27-20, 02:29 PM
  #1  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
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?
Amt0571 is offline  
Old 10-27-20, 10:46 PM
  #2  
cobba
Senior Member
 
Join Date: Aug 2006
Posts: 1,895
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 184 Post(s)
Likes: 0
Liked 67 Times in 53 Posts
Originally Posted by Amt0571
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.
How much is overhanging?

Is it possible that wide rotors have a slightly smaller diameter than narrow ones?
There shouldn't be any difference in the diameter of a narrow and wide rotor of the same size.

Post some photos.
cobba is offline  
Old 10-28-20, 03:05 PM
  #3  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts


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.
Amt0571 is offline  
Old 10-29-20, 01:17 AM
  #4  
TiHabanero
Senior Member
 
Join Date: Nov 2012
Posts: 4,435
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1726 Post(s)
Liked 1,350 Times in 705 Posts
If the posts are milled down 1mm will that resolve your concern?
TiHabanero is offline  
Old 10-29-20, 01:47 AM
  #5  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by TiHabanero
If the posts are milled down 1mm will that resolve your concern?
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.
Amt0571 is offline  
Old 10-29-20, 05:53 AM
  #6  
shelbyfv
Expired Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Location: TN
Posts: 11,455
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 3637 Post(s)
Liked 5,314 Times in 2,700 Posts
Contact the dealer/shop if it's still under warranty?
shelbyfv is online now  
Old 10-29-20, 06:31 AM
  #7  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by shelbyfv
Contact the dealer/shop if it's still under warranty?
The frame has been recently replaced under warranty for unrelated issues. The previous, identical frame had the same issue.
Amt0571 is offline  
Old 10-29-20, 06:45 AM
  #8  
shelbyfv
Expired Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Location: TN
Posts: 11,455
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 3637 Post(s)
Liked 5,314 Times in 2,700 Posts
^^ What did they say about your concern with the brakes?
shelbyfv is online now  
Old 10-29-20, 06:59 AM
  #9  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by shelbyfv
^^ What did they say about your concern with the brakes?
I didn't say anything about it as I was expecting a replacement frame anyway.

Also, the stock MT400 brakes didn't had this issue.
Amt0571 is offline  
Likes For Amt0571:
Old 10-29-20, 06:06 PM
  #10  
Troul 
Senior Member
 
Troul's Avatar
 
Join Date: Oct 2013
Location: Mich
Posts: 7,291

Bikes: RSO E-tire dropper fixie brifter

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2,910 Times in 1,884 Posts
mill the mounting surface on the caliper.
__________________
-Oh Hey!
Troul is offline  
Old 10-29-20, 06:24 PM
  #11  
shelbyfv
Expired Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Location: TN
Posts: 11,455
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 3637 Post(s)
Liked 5,314 Times in 2,700 Posts
Originally Posted by Troul
mill the mounting surface on the caliper.
That sounds like a good idea if possible, would not mess with the frame warranty.
shelbyfv is online now  
Old 10-29-20, 06:50 PM
  #12  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 7,765
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6882 Post(s)
Liked 10,872 Times in 4,637 Posts
Originally Posted by Amt0571
The frame has been recently replaced under warranty for unrelated issues. The previous, identical frame had the same issue.
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.

Last edited by Koyote; 10-29-20 at 07:01 PM.
Koyote is offline  
Old 10-30-20, 01:45 AM
  #13  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by Koyote
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.
The front caliper is identical and sits exactly the same way. I think I'm going to try a different rotor and see what happens...
Amt0571 is offline  
Old 10-30-20, 05:12 AM
  #14  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 7,765
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6882 Post(s)
Liked 10,872 Times in 4,637 Posts
Originally Posted by Amt0571
The front caliper is identical and sits exactly the same way. I think I'm going to try a different rotor and see what happens...
Not if it has a manufacturing defect.
Koyote is offline  
Old 10-30-20, 05:34 AM
  #15  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by Koyote
Not if it has a manufacturing defect.
Then it wouldn't work well mounted on the fork I assume.
Amt0571 is offline  
Old 10-30-20, 06:07 AM
  #16  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 7,765
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6882 Post(s)
Liked 10,872 Times in 4,637 Posts
Originally Posted by Amt0571
Then it wouldn't work well mounted on the fork I assume.
I think you're not understanding me. What if there is a problem with just the rear caliper?

You could swap the front and rear calipers in ten minutes to check this.
Koyote is offline  
Old 10-30-20, 06:21 AM
  #17  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by Koyote
I think you're not understanding me. What if there is a problem with just the rear caliper?

You could swap the front and rear calipers in ten minutes to check this.
You didn't understand me. I already did that. Both work well at the front. Both have the same issue at the rear.
Amt0571 is offline  
Old 10-30-20, 06:25 AM
  #18  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 7,765
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6882 Post(s)
Liked 10,872 Times in 4,637 Posts
Originally Posted by Amt0571
You didn't understand me. I already did that. Both work well at the front. Both have the same issue at the rear.
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.
Koyote is offline  
Old 10-30-20, 06:44 AM
  #19  
Amt0571
Senior Member
Thread Starter
 
Join Date: Dec 2014
Location: Catalonia
Posts: 956

Bikes: Canyon Grand Canyon AL SL 8.0, Triban RC520 Gravel Ltd, Btwin Ultra 520 AF GF, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 402 Post(s)
Liked 215 Times in 137 Posts
Originally Posted by Koyote
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.
I'm not a native english speaker. Sorry. I'll try to improve.

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.
Amt0571 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.