Juddering of front disc brake

Thigh_burn

I've got TRP HY/RD brakes on my Condor Fratello disc - steel bike with carbon forks.

In the past couple of days, the front brake has started to judder heavily when I brake. I checked the disc and there's nothing on it, I've also brushed out the brake pads to try to clear them of any mess, which there didn't seem to be.

I've also noticed, off the bike, that I have a slight amount of rubbing of the brake and the disc ie when I spin the front wheel, the wheel doesn't freely run, the brake is touching it.

If you've got brake disc experience, do you think the juddering and the rubbing are connected. I've never serviced disc brakes before, what I can do to fix the problem.

Final thing, and I really hope this is irrelevant, the other day I had the front wheel off the bike and the bike fell over on to the pavement. One of the forks took the brunt. I can't see any damage to it - and it feels fine whilst riding - other than when braking. Please tell me I haven't borked my fork :oops:

arlowood

Thigh_burn wrote:

I've got TRP HY/RD brakes on my Condor Fratello disc - steel bike with carbon forks.

In the past couple of days, the front brake has started to judder heavily when I brake. I checked the disc and there's nothing on it, I've also brushed out the brake pads to try to clear them of any mess, which there didn't seem to be.

I've also noticed, off the bike, that I have a slight amount of rubbing of the brake and the disc ie when I spin the front wheel, the wheel doesn't freely run, the brake is touching it.

If you've got brake disc experience, do you think the juddering and the rubbing are connected. I've never serviced disc brakes before, what I can do to fix the problem.

Final thing, and I really hope this is irrelevant, the other day I had the front wheel off the bike and the bike fell over on to the pavement. One of the forks took the brunt. I can't see any damage to it - and it feels fine whilst riding - other than when braking. Please tell me I haven't borked my fork :oops:

Unlikely a fall from upright would have damaged your fork sufficiently to have it misaligned. More likely explanation is the the fall may have disturbed the alignment of the Hy/Rd caliper. To re-align it just slacken off the mounting bolts and with the wheel in place apply the front brake so that the rotor is clamped firmly by the pads. Maintain the brake pressure while re-tightening the caliper clamping bolts. Spin the wheel to check that the pads are not fouling the rotor.

homers_double

I doubt it is as it'd be pretty hard to do but is the rotor warped in any way as I'm not sure a rotor touching the pad would cause juddering, more likely you'll just end up glazing your pads.

Try what Arlo said and see what happens.

pssyche

I had the same issues with HyRds on my GT Grade. It was driving me nuts, I changed the pads, swapped the rotors, realigned the calipers numerous times but the judder came back eventually. What finally get rid of it was changing cheap stock external qr levers to ultegra ones, I guess they didn't keep the wheel perfectly in place and even the slight misalignment with calipers caused the judder.

apreading

I had this very occasionally with my new 105 disc brakes. It was only once every 50 miles or so but REALLY worrying when it happened. I tightened the headset as that seemed the most likely, and I found it was a bit loose. Thought that had fixed it, then it happened again. Tried all sorts, including cleaning everything. Had just bought a new rotor and was about to fit it but switched front to rear and vice versa first - hey presto, nothing since. I read a few suggestions that it might be uneven thickness in the rotor which is very noticable in the front but not in the back - seems like this was the right answer for me.

veronese68

I'd start with the headset, you could try cleaning the disc with IPA. Isopropyl alcohol that is , not India pale ale.

vrsmatt

if the disc had been rubbing the pads then the disc will be glazed where it rubs,so the pads under braking wil be going from a good braking surface to a glazed one and back again every rotation of the disc........get some new pads, and disc cleaner, clean the discs and bed the new pads in properly to get some material all over this disc.

Before this check the disc isn't warped or its all pointless

homers_double

I'm sorry but the above is wrong as the pads will glaze, not the disc itself.

You don't get pad material over the disc either.

Thigh_burn

Thanks for the tips. I tried the fix mentioned above, which I then realised is the same as recommended by TRP, but I made the problem worse. Ended up taking it into my LBS who fixed it in no time! A mechanic, I am not.

homers_double

A mechanic you will be, ask question why? You should have...

apreading

Did the LBS not tell you what the cause was?

Thigh_burn

I did ask, but they weren't very clear. I was in a bit of a rush and frankly just glad to have got it back.
Explains why I'm a crap mechanic I guess

vrsmatt

homers double wrote:

I'm sorry but the above is wrong as the pads will glaze, not the disc itself.

You don't get pad material over the disc either.

Id be interested to know what part of bedding in doesn't deposit pad material on the disc surface......that's what bedding in is on a disc brake.

Go ask a car mechanic, they're just the same, and because of this the discs can also glaze as well as pads.

I've been using discs on bicycles for well over 20 years and am comfortable with the above :-)

Heres a link with a concurrent view on bedding in http://dirtragmag.com/disc-brake-breakdown/

homers_double

Fair enough but I still doubt it's the reason.

I've also been riding MTB's with discs for a very long time.

vrsmatt

homers double wrote:

Fair enough but I still doubt it's the reason.

I've also been riding MTB's with discs for a very long time.

It may not be the reason, but eliminating glazing of disc/pad and warping will mean the OP either cures it, or is one step closer to the solution and will have better brakes afterwards.

Discs are not as fit and forget as we all think, they require maintenance too, just in different ways

Davebo777

pssyche wrote:

I had the same issues with HyRds on my GT Grade. It was driving me nuts, I changed the pads, swapped the rotors, realigned the calipers numerous times but the judder came back eventually. What finally get rid of it was changing cheap stock external qr levers to ultegra ones, I guess they didn't keep the wheel perfectly in place and even the slight misalignment with calipers caused the judder.

I have front brake judder on my GT Grade. I swapped the rotors over but the front keeps juddering no matter how often I realign the caliper.

Might try the Ultegra QR as the other option is new 2 part rotors.

Any views ?

DBo.

The Rookie

2 part discs won't make any difference.

Check to see if the disc is warped (lift front of bike, spin wheel, observe) either straighten (using adjustables) or get any decent new disc.

Check the headset has no play.

Check the calliper is aligned, noting that if its been out of alignment for a while the pads will be worn off square so you need to align it manually not just by pulling the lever.

Any good internal cam QR can be used to see if it helps, you don't need to splurge on Ultegra until you've checked using a cheap one (noting you can of course use an MTB one as well).

pssyche

The Rookie wrote:

Any good internal cam QR can be used to see if it helps, you don't need to splurge on Ultegra until you've checked using a cheap one (noting you can of course use an MTB one as well).

Sure, but found them here at great price .