Calling all hydraulic brake road bike users

[Kbrook]

Can you let me know whether you suffer from the same as me? I have a road bike with Ultegra level hydraulic discs. It's done about 300 miles. When I brake on any descent the pads rub for about 10 seconds afterwards and then stops. This can only be down to heat build up, but bearing in mind we are only in Spring and it's not particularly warm it's worrying what it's going to be like in the summer.
I've centred the rotor to the caliper, cleaned everything including the Pistons, the rotor is pretty much straight and there is a gap either side of the rotor.
Two bike shops have told me they all do this and can't be improved, is this right? If not what can be done?
Fairly new to discs and already starting to regret the switch, bearing in mind I'm a bit OCD about bike noises.

 

[T.M.H.N.E.T]

Never noticed it if they do.

 

[Deleted member 23692]

Mine is a 'home made' set up with Ultegra brifters and Deore calipers and I don't experience what I think you're getting at. They work just as well as my other two MTB hydro setups

 

[Tom B]

I run mtb type disks on a hybrid.

They occasionally rub, more so after pumping some heat into them after a big stop or two. I have always assumed it was due to everything getting hot and expanding a fraction, this makes the gap between the pads a bugs whisker smaller and the disk a fraction thicker and there is your rub, until it cools down. I usually find just touching the brakes and letting them flick-off either gives me something to do until they stop it, or cures it.

The worst I ever had was after coming down one of the big meandering descents around here, unbeknownst to me the clown council had decided to authorise about 4 sets of temporary lights, so each time I hit about 40mph i had to slam on. After the last I was left with a significant rub and a hard lever. After stopping for a few mins it cleared itself. ( I think this was what prompted me to join CC and upgrade the brakes)

I have some crappy tektro cable op disks on another bike and they never seem to do it.

 

[tincaman]

I have the same brakes on two bikes, they both do that after hard braking

 

[raleighnut]

Disc brakes on road bikes are a 5hit idea, ugly, no better at stopping you, noisy and a 'moneypit'.

 

[T.M.H.N.E.T]

Disc brakes on road bikes are a 5hit idea, ugly, no better at stopping you, noisy and a 'moneypit'.

You're wrong on all 5 counts

 

[raleighnut]

You're wrong on all 5 counts

 

[keithmac]

If you get to the point when they are hot they bind constantly it could be because there's too much fluid in the master cylinder and no where for it to go.

You shouldn't fill them all the way to the top, there needs to be a bit of room to allow for expansion.

I've never seen what the op describes on my MTB setup and it's basically the same setup..

 

[Kbrook]

Thanks, interesting about not filling the reservoir all the way to the top, if it's not a stupid question how is that possible without introducing air into the system?

 

[Custom24]

Thanks, interesting about not filling the reservoir all the way to the top, if it's not a stupid question how is that possible without introducing air into the system?

Read yellow saddles explanation in this thread
https://www.cyclechat.net/threads/hydraulic-disc-brakes.216556/#post-4750490

There is air in the reservoir by design

I am not sure if this is the source of your problem, though.

How are you centering the calipers?
Is the rotor true?

 

[Custom24]

Actually I think you answered my questions in your OP. If there is an even gap both sides between pads and rotor all the way round one wheel revolution, when viewed with a torch or similar shining through the caliper, that rules out centering and rotor warp.

So I'm stumped. I haven't had the same issue with the 4 types I have.

 

[Kbrook]

Thanks, I've been centering it by eye, it has a nice if small gap either side and the rotor is true. Thanks for your help everyone,

 

[jowwy]

You're wrong on all 5 counts

I 2nd that quote

 

[dan_bo]

You're wrong on all 5 counts

seconded.

thirded.