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For anyone who is a luddite like me and still has rim brakes or anyone who can remember their rim brakes.
I have Ultegra Rim brakes on my Giant TCR road bike and there is of course a little plastic quick release lever that releases the tension on the caliper and moves the pads outwards so the wheel can easily be fitted and removed.
The lever on the rear brake is now partially stuck- i.e. it is in the usual closed position but rather than moving freely through (approx) 180 degrees to release the caliper tension it moves about 90 degrees and then absolutely refuses to go any further- with the calipers not really moving at all, meaning the wheel is stuck in the frame (unless I deflate the tyre or take the cable off completely).
I've tried GT85 on the back of the little lever but no luck. Is there any reason not to blast the entire brake caliper all over with GT85? (not the pads obviously). I guess maybe a pivot could have seized?
It was working fine like 3 weeks ago and the rear wheel gets put in and out a fair bit for cleaning duties so it's not like the QR mechanism isn't used regularly. Surprised if it has just seized up as the bike has 3 years riding from new but can't think of what else it could be.
Cable, levers and everything else all fine.
HAve you stripped and cleaned it?
what ultegra are you talking 6800?
From what I remember, that release lever just pivots the cable clamp and doesn't affect any of the other pivots, so blasting the whole brake won't help, (although won't do any harm either).
Does it just become very stiff, or does it feel like it's coming to a hard stop, as if it's jamming up against something? If it were me, I'd just dismantle the release lever and clamp bit to see if I can spot the problem, or at least properly clean and lubricate it.
I don't have an ultegra caliper to look at in front of me - but I have had similar issues with one. From what I remember it's reasonably easy to take the whole release mechanism apart (probably a small allen key needed), clean it up, lube it a bit and it'll be good as new. Blasting the mechanism with WD40 avoiding blocks can't do much harm either as a potentially quicker solution.
Thanks all. Have to say I am not sure what type of Ultegra the calipers are other than they come on a 2019 Giant TCR.
Yeah the lever comes to a hard stop rather than a gradual or spongy stop. Tried forcing it (up to a point) but no luck.
It looks like my next question has already been answered as I was going to ask how difficult they are to disassemble, clean, lube and reassemble but sounds like it's feasible to do so guess that will be option 2 after I douse it in GT85!
Cheers, Duggan
Might be better to undo the cable clamp bolt just to release the wheel rather than blast your brake/rims with GT85.
Some levers only go 90 deg are you sure it's not working as intended?
Yeah I'll take the wheel out first to protect rims. Definitely not working as intended- the calipers don't move at all when the caliper QR is released and the front caliper (which is working fine) QR moves through 180degrees.
It's totally rideable as the calipers move freely when the brake lever is applied so I can use my rear brake but it does mean if I puncture (or need to remove the wheel for any reaosn) I'll need to totally release the cable from the clamp, repair puncture or whatever and then clamp cable back again.
I had this on my new R8000 callipers while fitting them. I forget the details of how, but the cam on the lever gets trapped open when it spins through its travel when the calliper arms push against it. I think I released it by squeezing the calliper arms back in (as if braking).
I had an Ultegra calliper seize at the main pivot. I put it down to it being vulnerable to road spray etc over the years. As I remember, dismantling it requires removing a tiny grub screw which simply rounded out when I tried to turn it. I ended up buying a new calliper.
If you puncture the tyre will fit through the pads nicely 😀
I do recall the old calipers are pretty easy to dismantle and re-assemble.
You should be able to undo it with a torx key IIRC at the back. Give it a clean and you should be good to go.
As I remember, dismantling it requires removing a tiny grub screw which simply rounded out when I tried to turn it.
Yeah, that little grub screw is possibly in the worst place imaginable for collecting road salt and general grime and then NOT being easy to clean.
When i dismantle calipers i usually clean in out with a pick then some penetrating oil and grind a fresh tip on to a hex key (or use Hex+).