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Old 06-14-06, 02:08 PM   #1
John E
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early Campagnolo sidepull calipers

OK, engineering quiz for the day:

Why do even short-reach early Campagnolo sidepull brake calipers provide such poor braking performance? I have ca. 1980 Galli sidepulls which perform MUCH better than the Campagnolos, and mid-to-long reach (610 front, 750 rear) Weinmann Vainqueur 999 centerpulls which rank between the Gallis and the Campagnolos.
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Old 06-14-06, 04:02 PM   #2
lhbernhardt
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Centerpulls will provide more leverage than single-pivot sidepulls. Think of the caliper as a lever with the pivot as the fulcrum, and you'll immediately see why they should theoretically provide more braking power for a given input. The knock against the centerpulls is the sponginess coming from the cable anchor (and the flex in the calipers in the case of the long Weinmanns). The best compromise seems to be the dual pivot sidepulls we use today, which are a combination of centerpull on one side and single-pivot sidepull on the other (and cable anchor directly attached to the caliper). As for why the Galli sidepulls perform much "better," I don't know. I'd have to see and try them. Presumably they would be less spongy than the Weinmanns, but theroretically they should be equivalent to Campag. Maybe the pad composition? Does Galli still stop better when pads are switched? Are the same levers being used?

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Old 06-15-06, 04:28 AM   #3
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Quote:
Originally Posted by John E
OK, engineering quiz for the day:

Why do even short-reach early Campagnolo sidepull brake calipers provide such poor braking performance? I have ca. 1980 Galli sidepulls which perform MUCH better than the Campagnolos, and mid-to-long reach (610 front, 750 rear) Weinmann Vainqueur 999 centerpulls which rank between the Gallis and the Campagnolos.
My Campy Monoplaner brakes are single pivot. They are strong enough to catapult my 149lbs over the bars. My 233lb brother rode my bike and said that they didn't stop him at all. Are you a big guy, that may have something to do with it. Like the OP said double pivot have a mechanical advantage also. Good luck.

Tim
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Old 06-15-06, 06:30 AM   #4
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Campy used to claim that their brakes were made to control your speed, not stop you. Their current brakes are a lot better.

Yes, even the worst single pivot brakes will lock the wheels if applied with enough force but the benefit of dual pivots is the reduced force needed to brake over a long period. When you come down a five mile long twisty decent, the benefits of dual pivots are immediately apparent.
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