reggieob

Thanks everyone for the ideas - I've ordered a couple of different types of pads (including a pair like the ones above) and will give them all a try. Failing that I guess I'll start bending the calipers. I'm using my LeTour kid-Chariot-puller as the test subject so no great risk. Whatever works best I'll carry over to the other bikes...

David Newton

I used to hate squealing brakes, but now I find that I use the squeal sort of like a bell, to wake up people in my way.
Pretty picture Colonel.

sanmi

I know this is an old thread, but thanks all for the advice on bending calipers! Worked for me on a 1981 Fuji S12-S with Weinnman center pulls

Lascauxcaveman 

Once bent, just try not to bend them back the other way; you don't get a lot of do-overs with aluminum alloy.

seedsbelize 

Exactly

bikemig 

+ 1. Use a crescent wrench.

JohnDThompson 

Yes; the Park BT-3. Just don't use it on Universal calipers.

randyjawa 

another +1 from me and I use a 6" Crescent wrench. I have never seen a brake arm broken where the bend would have occurred. Has anyone ever seen such damage? Now would be a good time to chime in.

As for warning others with the brake noise, knock yourselves out. I hate that sound, just about as much as I hate the buzzing sound of brake pads contacting patterned rim surfaces...

dddd

What I mentioned in my post wasn't about breaking the arms at all. It was about the inevitable loosening of the entire pivot architechture, and not something that simply tightening the bolts can fix since this leads towards binding pivots as the ends of the 6mmx8mm diameter sleeves become mushroomed and dig into the alloy bridge that they absolutely rely on for a square seating that prevents the pivots from flexing in use toward a squeeling toe-out condition on the front caliper.
Having floppy pivots of course makes brake setup a more calculated exercise since there will be more actual toe-altering splay of the pivots as braking force is applied.

And as for the plastic bushings, I can't tell you how much good that wrenching on the arms does for them.

Again, where aligning a front caliper in it's mounting hole can put the pads into a more-symmetric alignment of the rim, this is preferable to bending the arms with the flimsy pivot bushing structure taking the force. And what little toe-in is perhaps still needed can be handled quickly by removing the front wheel and dressing the pad surfaces with a Dremel using a mounted stone.

I've sometimes used a chainsaw file to make the fork crown mounting holes more on-center with the front wheel, as there are certain caliper types where bending the arms is either damaging to the arms themselves (i.e. Universal) or to the bushing hardware. I also wasn't about to try bending the arms on my beefy 7400, Croce de Aune or Monoplaner front calipers just because the calipers would not center.

79pmooney

Every mechanic in my day had just the tool in his toolbox for aligning calipers. A carefully calibrated (metric ) Crescent wrench, usually 20 cm although in a pinch, 15 or 25 will do. Duct tape over the jaws if looks were important. Had settings to work on most brands of brakes.

Edit: If you are worries about the bushing, you can always take the brake apart, the bushings out and hold the brake at the pivots in a vice. Adjust as needed with the tool, reassemble with the virgin bushings and ride. (Is that why I like the Mafacs so much? Brass bushings?)

Ben

79pmooney

Ahh, the old Mafac, pre Kool Stop days! Set up right, I could get the front brake to stop me decently without a lot of noise but shriek if hit hard. Great in Boston traffic! Car cuts me off? I hit that brake hard. Everyone for two blocks around looks my way. I point to the offending driver. All eyes follow my point. Driver hears my squeal and looks up. Guess what? Everyone is looking at him! Driver slinks off with his tail between his legs.

Ben

dddd

Yes, you can bend the arms that way, but I usually find it pretty easy to align the hole in the fork crown as compared to disassembling and reassembling a Weinmann centerpull caliper.
These centerpull calipers are actually a chore to get back together with the springs pre-loaded in place, why I am loath to risk trashing the pivots.

And I get that shop mechanics almost always chose (and still do) the most expedient method of getting the bike out the door with quiet brakes.

Often it is the stickier aftermarket pads which make squeeling more of an issue, requiring greater toe-in.
I too appreciate the perfectly progressive noise action from a well broken-in set of Mafac brakes, it's just about right and has saved groups riding behind me from collisions with a few dogs imo.

One more thing about squeeling centerpull front calipers is that a "booster plate" between the pivot bolts prevents the pivot splay and squeal-inducing toe-out as braking force is increased. I found it simple to make one from .090" aluminum, shown here, as used for better braking in wet, off-road conditions. The cord tethers also remove the twisting force going into the pivots, maintain pad alignment with the rim and so really improve braking feel: