Road Bike, Cycling Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
234 Posts
Discussion Starter · #1 ·
Anybody know what I can do to keep my front Ultegra 6800 caliper rim brakes centered? They're less than a year old and the back brakes work fine. Front brakes, however, seem to go out of center after a few hard stops.

Here's what I've tried so far:
- Adjusting the calipers by hand
- Adjusting calipers using the center adjustment nut
- Tightening the brake bolt
- Adjusting the brake cable (giving it a bit more slack)
- Adjusting barrel adjuster

Hmm... wiggling the brake cable on the bike, it seems a bit tight. Could cutting some longer cable housing (so there's more play) help?

This is the first time I've encountered a brake centering issue that persists. Usually able to fix on first or second try.
 

·
'brifter' is f'ing stupid
Joined
·
15,567 Posts
You're not tightening the brake NUT enough. They're dual pivot brakes, if they're tight enough they can't move.
 

·
Registered
Joined
·
234 Posts
Discussion Starter · #3 ·
Thanks for the quick reply, CX. I'll try a little muscle and take it out for a spin. Cheers.
 

·
Banned Sock Puppet
Joined
·
14,449 Posts
Thanks for the quick reply, CX. I'll try a little muscle and take it out for a spin. Cheers.


Be careful if it's a carbon frame. Use a torque wrench.

As you said, if your housing is too short, that could possibly cause it too.
 

·
Registered
Joined
·
34 Posts
There is also a centering adjustment bolt that may help. Not sure where it is on your model, but its a 2mm hex that can move the calipers a little left or right.

The brake nut is torqued to only 10 lbs, so I agree with Lombard that its not something you want to over do.
 

·
Matnlely Dregaend
Joined
·
4,937 Posts

·
Registered
Joined
·
234 Posts
Discussion Starter · #7 · (Edited)
I did tighten down the brake nut and it seemed to help, but I'm starting to think that I do need to cut a longer piece of housing. The cable seems pretty taught.

The brakes were installed and adjusted by the LBS that I purchased the bike from, so not sure if there's a dented washer in there. Will check later, but working now.

I did try the centering nut, to no avail.

Thanks for all these responses.

Edit: Come to think of it, the problem could have coincided with me rewrapping the bars with new tape recently. I probably adjusted the cable routing which could explain the need for new housing, if that is the problem.
 

·
Banned Sock Puppet
Joined
·
14,449 Posts
The brake nut is torqued to only 10 lbs, so I agree with Lombard that its not something you want to over do.
10ft lbs??? I hope you mean 10Nm. Even that is way too high on a carbon frame. :yikes: Should be more like 7Nm which is around 5ft lbs.

When torqued properly, it should not be impossible to move, but it should give you some resistance.
 

·
Banned Sock Puppet
Joined
·
14,449 Posts
The cable seems pretty taught.
You definitely need a longer piece of housing. If it's taught, it is pulling the calipers off center.
 
  • Like
Reactions: fast ferd

·
Off the back
Joined
·
1,850 Posts
I could be wrong, but I thought carbon fiber fork construction uses a metal shaft for the brake bolt to slide thru. (Same thinking for a rear brake.) Therefore, you're tightening against metal, not carbon fiber.

Anyway, if one uses a small enough wrench - like a little allen key or short ratchet handle with an allen socket - it would spare the need to spring for a torque wrench. My thinking has always been the smaller the nut or bolt, the smaller the wrench. :idea:
 

·
Banned Sock Puppet
Joined
·
14,449 Posts
I could be wrong, but I thought carbon fiber fork construction uses a metal shaft for the brake bolt to slide thru. (Same thinking for a rear brake.) Therefore, you're tightening against metal, not carbon fiber.

Anyway, if one uses a small enough wrench - like a little allen key or short ratchet handle with an allen socket - it would spare the need to spring for a torque wrench. My thinking has always been the smaller the nut or bolt, the smaller the wrench. :idea:
Yes, there is a metal insert. But that metal insert is inserted into CARBON. A hard enough twist can rip the insert out of the carbon, and then....well....you don't want to know.

A smaller allen wrench to act as a poor man's torque wrench is not advised unless you know for sure you are unable to tighten it over the torque spec.
 

·
Off the back
Joined
·
1,850 Posts
Yes, there is a metal insert. But that metal insert is inserted into CARBON. A hard enough twist can rip the insert out of the carbon, and then....well....you don't want to know.

A smaller allen wrench to act as a poor man's torque wrench is not advised unless you know for sure you are unable to tighten it over the torque spec.
Yeah, you're right. Sometimes I get lazy and don't want to look up the spec, set up my torque wrench, etc. In a hurry to get out and ride!
Hey, Lombard, I tried to send you an RBR e-mail, but it said your box is full. Mine was close to full, as well, so it involved clearing old 'sent' items in addition to the inbox.
 

·
Banned Sock Puppet
Joined
·
14,449 Posts
Yeah, you're right. Sometimes I get lazy and don't want to look up the spec, set up my torque wrench, etc. In a hurry to get out and ride!
Hey, Lombard, I tried to send you an RBR e-mail, but it said your box is full. Mine was close to full, as well, so it involved clearing old 'sent' items in addition to the inbox.
Oh sorry, Fast Ferd. I cleared some, so now you should be able to PM me.
 

·
Registered
Joined
·
234 Posts
Discussion Starter · #15 ·
Thanks again for all the advice here, guys. I tried all of the suggested fixes; none seem to work. I've basically been doing most of the maintenance on my bikes the past 5 years or so. This is the first time I've encountered a centering issue this persistent. Maybe the calipers are defective or, worse, the metal insert in the fork is loose (although there is no more play compared to the back brakes).

Looks like I need to take this into the shop.
 

·
Registered
Joined
·
439 Posts
Locktite

My girlfriend's bike had this problem. I took the brakes off and reinstalled them with plenty of red locktite. The blue stuff wasn't strong enough. Make sure that the cable housings are the right length and use a torque wrench.
 
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top