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Proportioning Valve 2007 CBR1000RR ?

nebulous

nebulous

New member
Joined
Aug 12, 2008
Location
Emeryville
Moto(s)
2007 1000rr
2000 CBRF4
Changed the front brake pads on my 1000rr and noticed the left side was ~20% more worn than the right. When I was done, I noticed (or thought I noticed) a slight tug to the left when testing the brakes. Is this a thing? Is there need, or a way to adjust/proportion the application of the pads from left to right??
 
excessive uneven pad wear suggest theres an issue. the likely culprit is a filthy brake caliper on the left side. a 20% difference might not even qualify as excessive. I probably wouldn't worry about less than that... as long as your calipers are clean.

u do not need a proportioning valve for the brakes to function properly.
 
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since both discs are bolted to the same wheel, there's no way for one caliper braking harder to result in a pull to one side. plenty of bikes only have one caliper, and stop straight.

it's possible that you have sticky pistons on the caliper with more worn pistons, that's my best guess. I'd recommend cleaning them up.
 
Soap & water, SimpleGreen, or PineSol on calipers. rinse with water.

90% rubbing alcohol on rotors on a clean paper towel or two.
 
Junkie said:
since both discs are bolted to the same wheel, there's no way for one caliper braking harder to result in a pull to one side. plenty of bikes only have one caliper, and stop straight.

it's possible that you have sticky pistons on the caliper with more worn pistons, that's my best guess. I'd recommend cleaning them up.
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sum of moments about the steering stem would leave a non zero result. it'd have to be pretty big to be felt with the momentum of the wheel though. most things with a single rotor don't have, or need, brakes big enough to make the scenario likely. buell being the exception i can think of and they have the "Zero Torsional Load" thing, and i don't actually know what that means maybe they have a way around it.

as far as the OP's situation, i'd suggest it's dirty sticking parts too.
 
auntiebling said:
sum of moments about the steering stem would leave a non zero result. it'd have to be pretty big to be felt with the momentum of the wheel though. most things with a single rotor don't have, or need, brakes big enough to make the scenario likely. buell being the exception i can think of and they have the "Zero Torsional Load" thing, and i don't actually know what that means maybe they have a way around it.

as far as the OP's situation, i'd suggest it's dirty sticking parts too.
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I'd call the 15RCS/Braking 4pot/Braking 320 on my supermoto pretty significant braking, and it doesn't pull to either side
 
stangmx13 said:
Supposedly that’s too harsh for caliper seals and can leave a residue on rotors.
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Mechanics around the world use brake cleaner to clean calipers, pads, hardware and rotors. That is exactly what it is designed to do.
 
anytwowilldo said:
Mechanics around the world use brake cleaner to clean calipers, pads, hardware and rotors. That is exactly what it is designed to do.
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lots of mechanics around the world also do lots of things poorly or wrong :laughing

ask around a pro race paddock next time u are in one and ull get a much more informed opinion.
 
stangmx13 said:
Soap & water, SimpleGreen, or PineSol on calipers. rinse with water.

90% rubbing alcohol on rotors on a clean paper towel or two.
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Just be sure they are COMPLETELY dry when refilling the system with brake fluid. Also, replace your seals if you’re in there, be sure to soak the new seals in brake fluid before install. Wear gloves.
 
I googled around and after skimming about 8 pages, brake cleaner is safe for cleaning calipers.
 
Kawikiwi said:
Just be sure they are COMPLETELY dry when refilling the system with brake fluid. Also, replace your seals if you’re in there, be sure to soak the new seals in brake fluid before install. Wear gloves.
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why insist on completely dry? if the caliper seals cant keep water out of the system after cleaning, they've already failed. remember, brakes get used in the rain too.

I go through 2 sets of pads a year and try to clean my calipers at least 4x a year. so my seals are def not replaced every time im in there. but thats cuz im talking about a race bike.
 
stangmx13 said:
why insist on completely dry? if the caliper seals cant keep water out of the system after cleaning, they've already failed. remember, brakes get used in the rain too.

I go through 2 sets of pads a year and try to clean my calipers at least 4x a year. so my seals are def not replaced every time im in there. but thats cuz im talking about a race bike.
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My interpretation is that he's talking about removing pistons. In that case, you certainly don't want water on the inside when you reassemble.
 
^ that makes sense.

i was not suggesting to use soap & water for cleaning the calipers if they are completely disassembled and the pistons are out. thats for cleaning the calipers with the pistons in and the system intact.

i would use brake cleaner or some other strong degreaser if i was completely disassembling the calipers and replacing the seals because it evaporates so fast and isnt water-based.
 
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what I did last time I disassembled calipers is first used water/simple green, then rinsed well, blew it out with air, baked them in the shop oven at 175f (or whatever the lowest it would go was) for half an hour
 
dravnx said:
I googled around and after skimming about 8 pages, brake cleaner is safe for cleaning calipers.
Click to expand...

I have had caliper seals swell and bind with brake cleaner. What I infer is that, brake cleaner isn't safe on the seals, but you can get away with it most of the time because it evaporates away fast. I will not use anything stronger than warm soapy water on a caliper with seals in place now.
 
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