Successful 27" to 700c caliper brake conversion
04-27-20, 03:38 PM
#26
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My experience - the main part of pad wears and forms a "lip" that reaches over the radiused upper edge of the rim and works its way towards the tire.
My suggestion of chamfering is to remove that material before the lip forms.
Lowering the brake pad moves the upper edge onto the flat sides of the rim, below the radius.
Both options are meant to stop wear from allowing the pad to contact the tire.
It's up to you.
My suggestion of chamfering is to remove that material before the lip forms.
Lowering the brake pad moves the upper edge onto the flat sides of the rim, below the radius.
Both options are meant to stop wear from allowing the pad to contact the tire.
It's up to you.
Once I build a set of wheels and get this bike back together (something that may take months), I'll keep an eye on the pads as they wear. If I think of it, I'll try to revive this thread a year or so from now (assuming I remember and am still alive and stuff) and post an updated photo or two.
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Last edited by jonwvara; 04-27-20 at 05:44 PM. Reason: I am an editor
05-29-20, 05:43 PM
#27
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This is a hubristically misnamed thread if ever there was one.
The BR-M454 calipers gave me adequate tire clearance when I checked them with the 700C wheel from another bike. I knew that I might be pushing the envelope with wider Sun Rhyno Lite rims, but I'm an optimist, and they were the only new rims I could find in a 40-hole version for the rear wheel.
The front brake hits the rim properly, barely, with Kool Stop Thinline pads. Not sure about the rear because I don't have another set of Thinlines on hand. In any case, there was a separate, unrelated problem: when I installed the rear calipers on the posts it was evident that they didn't have anywhere near enough spring tension to work well. After some thought, I tried the modified brute-force method--turning the calipers outward hard against the spring to try to bend them enough to generate more pressure.
Bad idea. I didn't improve matters, but I did break the black plastic collar that goes around the spring. Not sure how to proceed from here. Maybe I'll buy some smooth-post Thinlines for the old Dia-Compe cantilevers--951s, I think they are--and see if they will reach the rims of the new wheels. Or maybe I'll do something else for a bit and wait for the dust to clear.
The BR-M454 calipers gave me adequate tire clearance when I checked them with the 700C wheel from another bike. I knew that I might be pushing the envelope with wider Sun Rhyno Lite rims, but I'm an optimist, and they were the only new rims I could find in a 40-hole version for the rear wheel.
The front brake hits the rim properly, barely, with Kool Stop Thinline pads. Not sure about the rear because I don't have another set of Thinlines on hand. In any case, there was a separate, unrelated problem: when I installed the rear calipers on the posts it was evident that they didn't have anywhere near enough spring tension to work well. After some thought, I tried the modified brute-force method--turning the calipers outward hard against the spring to try to bend them enough to generate more pressure.
Bad idea. I didn't improve matters, but I did break the black plastic collar that goes around the spring. Not sure how to proceed from here. Maybe I'll buy some smooth-post Thinlines for the old Dia-Compe cantilevers--951s, I think they are--and see if they will reach the rims of the new wheels. Or maybe I'll do something else for a bit and wait for the dust to clear.
__________________
www.redclovercomponents.com
"Progress might have been all right once, but it has gone on too long."
--Ogden Nash
www.redclovercomponents.com
"Progress might have been all right once, but it has gone on too long."
--Ogden Nash
Last edited by jonwvara; 05-29-20 at 05:48 PM.
