Bicycle Mechanics - Brake pad spacing question

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MAK
10-31-05, 08:39 PM
Wondering...On a properly adjusted bike, how much space should there be between the brake pad and the rim? Could you please answer in terms of things like "a dollar bill folded in thirds", "height of a dime, nickel, two penneys..." or some other easy to use measuring aide. It seems easier than using a ruler to eyeball.

Also...once the pad spacing is right, how far should the lever pull be before the pad engages the rim?

Thank you for any help.


urban_assault
10-31-05, 09:10 PM
MERTON asked this same question a few days ago...hold on and let me try the search function...brb

urban_assault
10-31-05, 09:15 PM
here it is

brake pad spacing question (http://www.bikeforums.net/showthread.php?t=149661)


supcom
10-31-05, 09:22 PM
There is no magic spacing number. You're good so long as the rim doesn't hit the pads. This distance varies depending on how long it's been since you trued your wheels.

Oh, and not so far that your brake levers bottom out on the bar when you squeeze them hard.

Oh, and if you have V-Brakes or cantilevers, not so close that you can't get the cable disconnected to pull your wheel.

Oh, and not so tight that the brakes rub when you've got a couple fingers on the levers for that white knuckle descent.

Basically, it's mostly a matter of personal preference.

jbone
11-01-05, 05:05 AM
For road caliper brakes I've always squeezed a penny between each pad and the rim and then tighten everything down.

CBolt
11-04-05, 02:20 PM
Just do it by how the lever feels. Also, there's other factors that must be correct to get the right feel, brake pad/rim alignment and cable friction.

DannoXYZ
11-04-05, 03:09 PM
For road caliper brakes I've always squeezed a penny between each pad and the rim and then tighten everything down.That's seems kinda close. You sure that wasn't to set the toe-in on the pads?

I usually set the pads so that when I'm applying FULL brakes and just about to lock up the front tyre, the lever is at about 2/3rds of it's travel (1/3rd away from the bottoming). This seems to give me the best feel and modulation on the lever. So whatever gap that ends up creating at the rims, that what I have. This gap will vary between different brake-lever & caliper combinations. But I'll always set it so the feel at the lever is about the same. :)

San Rensho
11-04-05, 03:14 PM
I do it by feel also. I set the rear brake (which I rarely use) very loose. In hard braking the amount of braking it does is almost negligible, since almost all the weight of the bike and rider has transfered forward and I don't want to lock up the rear in a panic stop.

Brian
11-05-05, 01:11 AM
No more than 12 cents worth of space, depending on the width of the rim. Six cents per side. Don't use pennies.