Brake callipers not long enough to allow adjustment of pads

Question

I upgraded the standard Tektro brakes on my SE Lager to Shimano 105s. The braking performance is vastly improved. I also have Charge Plug wheels, rather than the stock wheels.

However I've noticed that there's not quite enough adjustment in the calipers to position the pads correctly. Even at the lowest position in the caliper arms, the pads are still very slightly too 'high' and overlap the upper curve of the rim.

Is this a problem? Is there anything I can do to solve it?

Brake location

Swiss I'm considering filing out some shimano r650 long drop brakes to make them fit. I'm wondering how have the brakes on your giant ocr c1 gone in the long run. Did you ruin them or are they still going strong? — , May 23 '14 at 21:10

score 12 · Accepted Answer · answered Oct 25 '11 at 00:13

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Those pads do look ever-so slightly too high on the rim, the main danger being that any slight vertical eccentricity could result in the pad contacting the tire and causing a blowout.

There are two main solutions:

Firstly, you could use a round file and simply file out the bottom of the slot slightly to increase the clearance. This works best if you only need a very small amount of additional reach and are willing to accept permanently modifying your brakes.

Secondly, you could buy a set of brakes with a longer reach. The Shimano 105mm calipers are 39-49mm reach; if you instead purchase some higher-quality dual pivot calipers that are 47-57mm reach you'd have plenty of room for adjustment and should be able to achieve equally good braking capability.

answered Oct 25 '11 at 00:13

lantius

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+1 on a set of longer reach brakes. Ultegra level brakes come in an optional long reach version. Older 105's did as well. Probably best not to remove material from the caliper arm. You'd probably be alright, but the chance of reducing the integrity on a crucial component of your bicycle isn't really worth it, plus you're mucking up your resale value. Is it only an issue on the front? If so, have you considered upgrading the fork? – joelmdev Oct 25 '11 at 00:48
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Bloody hell bike gear is so frustrating! Nothing fits anything else, there's no standards and no compatibility. Pretty much every component I've tried to upgrade over the years hasn't fitted. I thought that brakes at least are pretty standard. Arrrgghhh! – Mac Oct 25 '11 at 00:56
Thanks for the advice. Trouble is I've spent my budget on 105s. Having to buy more brakes (or a fork, which would then probably not be compatible with other stuff) is going to stretch it. – Mac Oct 25 '11 at 00:58
did you get them from your lbs? they may take them back... – joelmdev Oct 25 '11 at 01:01
I guess I can try. I've been riding with them for a few weeks now though, so I doubt it. – Mac Oct 25 '11 at 01:19
I shouldn't whinge. Clearly I need to more/better research. – Mac Oct 25 '11 at 01:19
If your LBS was any good they would have seen, or known beforehand, that they didn't quite fit and suggested, or gotten you something that would. If you're buying parts yourself and doing your own repairs, then you are bound to run into something that won't quite fit. – Jason S Oct 25 '11 at 10:14
Jason is right. If you're lbs installed, that's pie on their face and they should make it right. If you installed yourself, uninstall, clean them up, and be honest about what happened. They may still offer trade credit. This is not an uncommon problem. – joelmdev Oct 25 '11 at 15:29
@JasonS yes, they should have picked it up. I bought the bike there and also they suggested these brakes. – Mac Oct 26 '11 at 09:08
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What do people think of shaving off the top of the brake block? Seems preferable to filing the calipers. – Mac Oct 26 '11 at 09:09
@Mac I'd try and hold them to account. If they suggested them and installed them, even if you've been using them, they do have some responsibility to rectify. Safety could be something to bring up. There is the possibility of tyre damage or blowout, in which case you may be injured, possibly badly. – Jason S Oct 26 '11 at 21:00
@JasonS I installed them myself. – Mac Oct 26 '11 at 21:18
@Mac Still they recommended them for the bike they sold you, so I'd ask them at least, what they would recommend you do now, or if they can fix or replace them. This might come under "not fit for purpose", entitling you to remedy by them. I'd say it was reasonable you relied on their expertise when they recommended those brakes for the bicycle they also sold you. Anyway hopefully it doesn't have to get messy and they will help you out. – Jason S Oct 26 '11 at 22:50

score 2 · Answer 2 · answered Dec 05 '11 at 12:28

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I have just had to do the same thing with ultegra brakes on my Giant Ocr C1. Filed them down so theres only a millimetre or so at the bottom. Working well so far. Only needed to adjust the rear so at least ill have my fronts if they fail :-/

answered Dec 05 '11 at 12:28

Mr-swiss

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score 1 · Answer 3 · answered Mar 21 '21 at 00:38

Yes - there are several ways to alter the relationship of the caliper to the rim, but they all have downsides of adding flex or more complexity to the brake system.

Drop the pads down The suggestion of filing has been made, that that's okay if you only need a millimetre. Depending on the beefiness of the metal, you may not have a lot remaining. Enter the offset brake pad holder:

These simply change the relationship of the pad to the bottom of the caliper.

Downsides

They can rotate in place. Since the braking force is not through the single fixing bolt, there is a torque applied. This might rotate the pad holder under aggressive braking. I suspect the left side of the bike would be most at risk. Mitigate by using thread lock and torque.
The holder might interfere with the tyre. Here the top of the holder touches the sidewall under braking:
^{From https://www.bikeforums.net/classic-vintage/1112364-650-bdop-cautionary-tale.html}
So this rider ended up grinding some relief into the rear of the holder. Risk is that as the brake pad wears, this will touch the tyre again causing quiet sidewall damage and risk a blowout.
Also mechanical advantage is decreased. As the pads get further from the pivot, the force applied to the rim will decrease, resulting in less braking effect.

Another answer is to lower the entire brake caliper to be lower by dropping the brake-bridge mounting hole with an offset adapter.

Downsides This would be a neat solution, but there's potential for the whole caliper to flex under braking. Also this increases leverage on a single small mounting bolt, so make sure its a good one.

Here's a home-made version of the same:

Brake callipers not long enough to allow adjustment of pads

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