Widen SRAM Force rim brake calipers?
02-09-23, 08:46 PM
#1
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Widen SRAM Force rim brake calipers?
I acquired a 2007 Felt FC road bike and am rehabbing it for personal use. I am having difficulty with setting the rear brakes (SRAM Force rim calipers): the only way I have even barely enough clearance between the (new Kool Stop) brake pads and the (Bontrager RL, ~23.5 mm OD) rims is if I completely loosen the pinch bolt and release the caliper lever in the up position - and even then there's very minimal clearance.
When I adjusted the front brakes there was plenty of room to play with (same caliper, rim/width and new pads) - which is why I'm confused about the difference in the rear brake.
Admittedly I am not well-versed in SRAM components but have learned a couple of their nuances while rehabbing this bike. I'm wondering if this might be another one - like some sort of a "limit screw" in the brake caliper?
Any relevant feedback is appreciated. Many thanks in advance.
When I adjusted the front brakes there was plenty of room to play with (same caliper, rim/width and new pads) - which is why I'm confused about the difference in the rear brake.
Admittedly I am not well-versed in SRAM components but have learned a couple of their nuances while rehabbing this bike. I'm wondering if this might be another one - like some sort of a "limit screw" in the brake caliper?
Any relevant feedback is appreciated. Many thanks in advance.
02-09-23, 08:57 PM
#2
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Force rear calipers work exactly like the front ones. I've only used SRAM, Shimano, or Jagwire pads on mine so I don't know what to say without seeing a photo.
02-10-23, 01:37 AM
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I suspect that you might be using the wrong brake shoes.
Generally, brake shoes intended for ATB are thicker, (brake arm to rim) than road shoes.
For example, KoolStop makes (made?) 2 similar shoes, Supra & Eagle Claw. If you're using Eagle Claws, then Supras will solve the problem.
The other possibility is that you're using a rim significantly wider than typical. Brake designers engineer for the expected rim width, and don't leave much room for wider. In this situation, the workaround Is to seek out a thinner shoe (yes, they vary) or use a rasp to shave the shoes down.
Generally, brake shoes intended for ATB are thicker, (brake arm to rim) than road shoes.
For example, KoolStop makes (made?) 2 similar shoes, Supra & Eagle Claw. If you're using Eagle Claws, then Supras will solve the problem.
The other possibility is that you're using a rim significantly wider than typical. Brake designers engineer for the expected rim width, and don't leave much room for wider. In this situation, the workaround Is to seek out a thinner shoe (yes, they vary) or use a rasp to shave the shoes down.
02-10-23, 01:47 AM
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He says he has the identical stuff front and back and the front is fine. We need to see it.
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02-10-23, 02:06 AM
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So, I post here differently than if I were to deal with an issue in person.
To the OP, eliminate possibilities by starting without any cable at all. Then measure inside arm to arm distance.
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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02-10-23, 03:56 AM
#6
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I have Force calipers on Fulcrum Racing 6 wheels, which are, as close as I can measure, the same external width as yours. I've not had any trouble fitting new brake pads so either something is wrong with that rear caliper or you've got the wrong pads in there. I actually have Kool Stop pads installed at the moment. The correct pad is the Dura 2 cartridge insert. They come in different flavours depending on the anticipated conditions, but I get good results with this one. The idea is that you loosen the screw holding the pad (we used to call them brake blocks when I was young) in place, slide it out, slide in the new one and tighten the screw, rather than replacing the complete unit as you would with V-brakes. If you've chucked the complete cartridge out I presume you can get replacements. Hope that helps.
02-10-23, 04:07 AM
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Are the rear pads hitting the frame's seat stays?
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