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Old 01-14-10, 08:00 AM   #1
TurbineBlade
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Moving spacers on brake pads...

Does moving spacers on the pads to push the actual pad closer to the rim at rest increase power?

I am referring to tektro oryx cantilevers with v-brake pads.
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Old 01-14-10, 08:04 AM   #2
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i dont see how this is any different than just running the cable a little tighter.
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Old 01-14-10, 08:18 AM   #3
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Correct. The spacers really only position the pads closer to the rim*. Though some will argue that the angle is most important. I suggest you position the pads so they are going to strike the rim, when you apply the brakes, as square-on as possible so the largest area of the pad contacts the rim as possible. Remember to toe-in the pads with the spacers - and test ride to make sure the brakes stop you as effectively as possible.


* and angle the pads with a gentle toe-in position.
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Old 01-14-10, 08:31 AM   #4
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i dont see how this is any different than just running the cable a little tighter.
My first thought as well as I was pushing this around in my head, but I don't think it is true. I think spacing the pads inward toward the rim further changes the geometry of the pads with respect to the brake arms. I just didn't know if it makes a difference or not.

The instructions for tektro oryx brakes says that you can move a spacer around if you want, but it might just be for proper angle based upon your rim width and bike fork.

Maybe not.
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Old 01-14-10, 09:12 AM   #5
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Circle A cycles just addressed this sort of thing:

http://www.circleacycles.com/cantilevers/
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Old 01-14-10, 09:30 AM   #6
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I think spacing the pads inward toward the rim further changes the geometry of the pads with respect to the brake arms. I just didn't know if it makes a difference or not.
It does make a difference, and can be used to correct for narrow rims on a bike with widely spaced cantilever posts, and vice-versa. Play around a bit in MAITOY by bbelhumeur ( http://www.circleacycles.com/cantilevers/ ) and you'll see what I mean.

It's different from running the cable a little tighter.
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Old 01-14-10, 09:44 AM   #7
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If it's hitting the rim square-on, I don't see why placement of the spacer(s) make a difference. My v-brake pads are aesthetically incorrect for the placement of the spacers - but the contact the rim better than if they look pretty and clean.
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Old 01-14-10, 12:39 PM   #8
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spacers are for adjusting the arm position during pad contact. for v brakes the arms should be vertical when the pads contact the rim.
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Old 01-14-10, 12:58 PM   #9
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spacers are for adjusting the arm position during pad contact
I think the conical washers are for aligning the pads, the spacers are for keeping the pads fixed at a certain distance from the brake arms because they are threaded instead of the old style.

Not to be argumentative - I just don't think that is correct either.
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Old 01-14-10, 01:02 PM   #10
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The instructions for the Shimano V-brakes say you should use whichever spacer setup that allows at least 39mm of cable between the noodle and the allen bolt. I don't know how that correlates to braking power, but it does affect the position of the brake arms, which may affect leverage.
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Old 01-14-10, 01:03 PM   #11
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Originally Posted by Gene2308 View Post
I think the conical washers are for aligning the pads, the spacers are for keeping the pads fixed at a certain distance from the brake arms because they are threaded instead of the old style.

Not to be argumentative - I just don't think that is correct either.
Yeah, I've never had a problem getting the pad to hit the rim square and properly on either setting. I just noticed that it changes where the arms are, and it seems (this is just perception) that I get mushy braking if the arms are too close to each other.
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