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Old 06-12-06, 09:34 PM   #1
48yearoldN00b
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Adjusting Vee brakes

I've got Promax Vee brakes on my bike, and while the cable tightness for the rear brake is about right, I notice that one pad rubs against the rim (lighty) continuously.

Like all the slack in the cable when released, plays out on one side of the wheel only. is there anyway to adjust this? So that the gaps when released would be centered?

Here is a picture, and I'm wondering if the screw running tangentially to the caliper arms main pivot (above the d in "Radundtat") is some form of adjustment screw?



Thanks for any tips
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Old 06-12-06, 10:12 PM   #2
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Try this ....

V brakes would appear to be straightforward, but adjusting them is not. If one boss or the other is a bit sticky this will affect performance. Remove the caliper arms, clean and lube the bosses. Make sure they are perfectly smooth (no burrs!) while you have the arms off. Blue Loctite 242 on the holding bolts when you re-install the arms. Spring tension on both sides must be very close for the adjustment screws to work correctly. Sometimes you have to bend one a bit to strengthen it (compared to it's mate). The adjustment screws should always be adjusted both sides at the same time - loosen one side and tighten the other. If things seem all out of whack, set both screws at a middle position (blue loctite on these guys, too). The side of the brake that moves the most when squeezing the hand control should be loosenned (turn adj screw out) and the other side should be tightenned (turn screw in). Loosenning the adjustment screw reduces spring tension on that side and if one arm is moving more than the other, it has too much spring tension and the way you fix that is by reducing it (turn screw out) - and then go to the other side and increase spring tension by turning the adj screw in (the same amount as you turned the other one out). If your bosses are lubed and the springs are close to the same tension, you will know when you make the correct adjustments because you will see both the left and right arm move (at the same time) to the needed side. Sometimes it will take several sets of adjustments to get both arms to move at once. Once you see them both move at once, you are very close to the correct adjustments. If you get an over correction, go back the other way and use smaller adjustments. It's correct when both arms are at the same angle away from the fork (or seat stays) and they both move the same amount to make the pads contact the rim.

Hopefully, this will get you going in the right direction. Good luck!
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Old 06-13-06, 04:44 AM   #3
motorhommmer
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Quote:
Originally Posted by 48yearoldN00b
I've got Promax Vee brakes on my bike, and while the cable tightness for the rear brake is about right, I notice that one pad rubs against the rim (lighty) continuously.

Like all the slack in the cable when released, plays out on one side of the wheel only. is there anyway to adjust this? So that the gaps when released would be centered?

Here is a picture, and I'm wondering if the screw running tangentially to the caliper arms main pivot (above the d in "Radundtat") is some form of adjustment screw?



Thanks for any tips
Yes it is an adjustment screw. There is one each side of brake. The balance the side to side spacing of the brake pads. Tighten the screw will cause brake pad to move out from rim, loosen will cause it to move back. It is called centering the pads on the rim. It is a standard v brake adjustment. Go to www.parktools.com
http://www.parktool.com/repair/readhowto.asp?id=21

Inspect pad centering to rim. Use set screw on sides of caliper to center pads to rim. Tighten setscrew on arm with pad that is closest to rim. Inspect that pads are not rubbing tire. Re-adjust if necessary. Clean the rim surface and test ride bike.
Use centering screws to move arms and center pads to rim
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Old 06-13-06, 10:19 AM   #4
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Thanks to both of you. I was wondering if those were adjustment screws,but I hate to start cranking on something when I don't know for sure what it does.
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Old 06-13-06, 01:51 PM   #5
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Before fiddleing with the adjusting screws, make sure the wheel is centered in the dropouts. Many a rubbing brake pad can be solved by centering the wheel.
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