why centering screw on dual pivot brake?
05-20-21, 07:17 AM
#1
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why centering screw on dual pivot brake?
question. why not just take a flat wrench, another wrench on the back, and turn to adjust centering? Why centering screw?
or is this screw has another purpose?
or is this screw has another purpose?
05-20-21, 07:25 AM
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Interesting question. I've never touched the centering screw on any dp brake I own as they can be centered by hand with no difficulty. Single pivot brakes with their tricky centering are a different matter but even then it can be done without using a centering screw.
05-20-21, 07:54 AM
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I've found them to make life much easier than fiddling around with getting the brakes perfectly centered by mounting bolt only.
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05-20-21, 08:17 AM
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05-20-21, 08:28 AM
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Because it's a much better way to adjust the arms, IMO.
I've had some brakes of long ago that were almost impossible to center precisely by simply re-adjusting the mounting bolt.
I've had some brakes of long ago that were almost impossible to center precisely by simply re-adjusting the mounting bolt.
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05-20-21, 08:35 AM
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You have a bit of an odd bird there. Most of the dual pivot brakes I’ve seen don’t have a wrench flat behind the brake. Most of them also aren’t nutted like yours is. All in all, the centering screw is easier to use and much more precise.
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05-20-21, 09:19 AM
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The issue with the centering screw, if used too much, is that the geometry of the pivots, the pads and the rim also change. We have seen screw adjusted calipers that have the pads touching the tires because the doer didn't know to first roughly center the caliper with it's mounting bolt AND then use the screw for the fine tuning. L:ike so many features the screw is both a help and a hinder, dependent on how it's used (or not, as with indexing trim points that are not understood). Andy
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05-20-21, 08:02 PM
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05-20-21, 08:08 PM
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Not odd at all. The pads are upside down but it’s not uncommon to have a angle on the pads.
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05-20-21, 08:10 PM
#11
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this is front brake, of course. the arrow doesnt match the tire direction. interesting?
L and R marking...indicates the pad is on the proper sides...
L and R marking...indicates the pad is on the proper sides...
Last edited by mtb_addict; 05-20-21 at 08:14 PM.
05-20-21, 08:13 PM
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Why not spring for some quality:
https://www.aliexpress.com/item/3290...c&gclsrc=aw.ds
https://www.aliexpress.com/item/3290...c&gclsrc=aw.ds
05-20-21, 09:32 PM
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As was already mentioned, your pads are upside down. The thicker part goes at the bottom. With many aluminum rims the sides are straight up and down and the angle of the pad isn't as significant but with narrower rims the arms come in far enough that they aren't parallel to the braking surface and angled pads are the solution for best pad engagement. With steel rims the sides are typically not straight and the angle of the pad helps them better engage. The arrow should be read from looking down. Just fix the pad.
05-20-21, 10:21 PM
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As was already mentioned, your pads are upside down. The thicker part goes at the bottom. With many aluminum rims the sides are straight up and down and the angle of the pad isn't as significant but with narrower rims the arms come in far enough that they aren't parallel to the braking surface and angled pads are the solution for best pad engagement. With steel rims the sides are typically not straight and the angle of the pad helps them better engage. The arrow should be read from looking down. Just fix the pad.
ok. fixed it. the rim is 26"x1-3/8 rim. this caliper with these pads stop ok. i wonder if i should find some parallel pads. Or maybe these will wear down to parallel fast.
pads not parallel to rim...
Last edited by mtb_addict; 05-20-21 at 10:27 PM.
05-21-21, 10:04 AM
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The brakes themselves are some of the weakness, they don't look too stiff. If you want more pad contact take a knife and trim the bottoms, don't do this with the wheel in the bike at the same time, or use a file, either will get it flatter to the rim and give a little more friction.
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05-21-21, 10:15 AM
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To be clear, those pads are a hold over from an era when the rims may not have had completely vertical walls. But pads are something that are easy to change.
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Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
