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Old 04-03-08, 10:13 PM   #1
lamberticus
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Better braking than my center pulls?

i was really hoping by adjusting my brakes and with new pads (kool-stop continentals) my front stopping power would be awesome, but they are not. I can stop pretty well, even wet, but still i'd like to be able to flip myself over if i really wanted to. Is the problem the fact that i have center pull calipers? would different brakes (like side pull calipers) work better? Currently even though my pad to rim clearance is like 1/8" i am not too impressed and would like better. My levers have plenty of clearance to the bars, I think, but want better performance. Thoughts?

Andy
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Old 04-03-08, 11:58 PM   #2
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1/8" clearance is way too high. Closest without rubbing is best, -adjust accordingly. I run less than 1/16" on my center-pulls and have great brakes. If your rims have a lot of runout you may need to adjust your spokes.
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Old 04-04-08, 12:11 AM   #3
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That material is really nice and grabby for me. But while the salmon color material works better than the others it's not a sudden head over heels better. It's maybe a 1/6 to 1/5 less effort to stop at the same rate as the old pads? Something like that.

Did you find that the new pads at least worked a bit better than the old ones?

If you're looking for one finger "lift the back up" sort of stopping effort then you'll need to move to disc brakes. Or possibly one of the better pads on some V brakes. And either of those means a new bike.
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Old 04-04-08, 12:35 AM   #4
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i use the salmon pads, and to be honest they are really close to the rims, probably less than 1/8
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Old 04-04-08, 01:06 AM   #5
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From the picture, it's your brake caliper, too old tech.
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Old 04-04-08, 01:52 AM   #6
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From the picture, it's your brake caliper, too old tech.
Hope that was sarcasm.

Side-pulls won't give you better braking. Aero levers (cables under the handlebar tape), if you don't have them, will help. So will new cables.
Dual pivot calipers are good, but not head over heals better than center pulls.
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Old 04-04-08, 03:33 AM   #7
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From the picture, it's your brake caliper, too old tech.
No, the center pulls are not the problem. They are great brake systems and work well. I can do a front wheel stand easily under braking with mine and I weigh 225#. That is also with pads that are over 10 years old.

When the brakes are operated there is a certain amount of give and flex in the cables themselves that depends on cable length and mounting. The flex is both in the cable jacket and the cable itself. When brakes are far out of adjustment much of the brake lever travel is taken up by the pre travel before the pads even contact the rims which can reduce the amount of force applied to the rim by the pads. Adjust the cable to keep the pads as close to the rims as possible for best performance.

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Old 04-04-08, 06:16 AM   #8
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Along with some of the above comments, I would add that I have noticed a difference in different versions of center pull brakes.

For Dia Compe or Weinmann, which it looks like you have, some models (perhaps later versions) seem to work better. Dia Compe and Weinmann are virtually the same brake... as well as the similar Schwinn approved.

Some have a little nub in the front arm that slides in a slot in the rear arm. A small change, but it seemed to increase the rigidity of the brake.

In addition, taking the brakes apart, cleaning them real well, and lubing the pivot points and cables seems to help a lot. Make sure the pivot bolts and mounting bolt are all tight.
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Old 04-04-08, 07:09 AM   #9
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A better cable hanger will also improve things. Those older stamped steel hangers flex a lot under load.
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Old 04-04-08, 07:17 AM   #10
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A well set-up centerpull brake will stop you as well as any other road brake. No road brake will have the power that a well set-up canti or V brake.

People moved away from cenerpulls for weight and aesthetic reasons. Not for performance reasons.

Do you have steel rims? If so, then no rim braking system will be all that good.

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Old 04-04-08, 07:47 AM   #11
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I don't buy that aero levers are better. In my experience, they're just as good, but if you think about the simpler cable path that non-aero levers have, they ought in theory to be marginally better.
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Old 04-04-08, 07:52 AM   #12
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"better" can mean different things. Aero levers do pull more cable, and so can overcome some other systemic problems in a brake set-up. For example, it allows a bit more leeway about how far out the pads are from the rims.

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Old 04-04-08, 08:05 AM   #13
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not sure if this has anything to do with anything..but what kind of rims do you have? They steel or aluminum??
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Old 04-04-08, 08:50 AM   #14
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I don't buy that aero levers are better. In my experience, they're just as good, but if you think about the simpler cable path that non-aero levers have, they ought in theory to be marginally better.
While that would seem a logical conclusion, it's the pivot placement within the aero lever that provides for a more efficient action. It gives a bit more mechanical advantage over non aero levers.
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Old 04-04-08, 11:01 AM   #15
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As for some of the questions you have been asking, I currently am using new aluminium alloy rims, new cables and housings, and a pair of Tektro R200A aero levers. I'm thinking the cable hanger might be part of the issue, I do notice that it flexes pretty readily when the brake is applied hard.
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Old 04-04-08, 11:08 AM   #16
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Oh, and yes, they are Dia Compe brakes and the bike dates (brakes I imagine too) to 1980. They are mechanically smooth and in good shape (as far as I can tell!)
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Old 04-04-08, 02:04 PM   #17
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I like the look of Centre pull brakes.

Dont like the effectiveness though..

Ive got Weimmann, Shimano, Mafac and er 88 brakes.
Have to see which ones more effective.
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Old 04-04-08, 02:07 PM   #18
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Flex in the hanger will only show up as an issue if your levers can touch the bars. Otherwise the only issue will be a spongy lever feel. The pressure at the lever will still reach the pads. So you're stuck with you either need more leverage to put more pressure on at the pad or you need pads with a higher coefficient of friction so they grab harder for the same pressure.

This is why canti's and even moreso V brakes are so popular. They provide that system leverage ratio to put more pressure on the pads for the same lever pressure.

But again, you're stuck with the center pulls since your posts are attached to the frame for them. Keep them clean and keep the jackets in good shape and that's about all you can do.

Oh... and the pads on there may grip better after a few dozen stops when the faces wear in and mate to the rim face more completley. I've found that it always takes a few dozen stops for the pads to wear in and fully grab.
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Old 04-04-08, 02:14 PM   #19
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I would try a modern cable hanger.
Either a flat one or a cast alloy one that hangs down a bit, if the cables to close to the stem.

Looks like he could use normal sidepulls on there as the forks are drilled in the centre of the crown.
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Old 04-04-08, 02:44 PM   #20
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Shorten the cable that bridges the two halves of the caliper if you can, I think that should be possible. Right now it has some arch to it, but you'll be able to exert more force on the rim if you straighten that cable out a bit. I think I saw a writeup about why it works somewhere, but it was about cantis, not your kind of brakes. The physics is similar.

Check Sheldon on mechanical advantage. See if that makes any sense.
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Old 04-04-08, 03:34 PM   #21
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I can squeeze the lever all the way to the bars, so this is indicating to me that i may have too much mechanical advantage. Looks like lengthening the yoke cable would help in my case, I guess? That way I would have to squeeze a little harder, but not as far on the lever. Am I getting this right? That and a new cable hanger.
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Old 04-04-08, 03:46 PM   #22
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You would want a slightly shorter yoke cable, not longer. Bike tools sells a 100mm yoke cable: http://www.biketoolsetc.com/index.cg...id=DC-B1270.10

If that's shorter than what you have, give a shot. Usually the front brake has shorter arms and a shorter yoke. The back has longer arms and a longer yoke. I could be wrong but it looks like you might have a rear brake length yoke on there.
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Old 04-04-08, 04:34 PM   #23
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Best two things you can do is salmon kool stops and aero levers. You've already done one, you're halfway there. My old Dia Compe centerpulls with salmon kool stops and aero levers stop very, very well.
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Old 04-04-08, 04:44 PM   #24
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He's got aero levers.

I think you just need to take up some slack and get the pads closer to the rim, and perhaps a new, shorter yoke cable. Check ebay too.
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Old 04-04-08, 06:01 PM   #25
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He's got aero levers.
My mistake, I was lazy and didn't read through the thread before posting.
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