SRAM Code RSC - pads clearance adjustment possible?

salko

E*POWAH Elite World Champion
Aug 29, 2019
1,235
835
SLO
I have upgraded Guide RE's brakes to Code RSC, but I have problems adjusting the caliper to prevent any rotor rub - it seems that clearance between pads and rotor is a bit to small. I have 220mm SRAM rotor (which is 2mm thick) which does not show any warp. Already pushed pistons all the way in using bleeding block and after mounting the caliper back there was about 1mm of clearence on each side of the rotor, but then I pumped the lever the pads moved in and again stayed quite close to the rotor. Is there any way to adjust this clearance of the pads to the rotor on these brakes? I already dropped a few drops of DOT fluid from the lever side and I think it helped a bit, but I would still want a bit more pads clearance to prevent any rub, possible?
 

Gary

Old Tartan Bollocks
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Mar 29, 2018
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I already dropped a few drops of DOT fluid from the lever side and I think it helped a bit
When you say this do you mean you opened the lever bleed port and pushed the pistons back into the caliper housing?
This will releive the system of fluid if overfilled.
your new disc rotors being 0.15mm thicker than stock is however always going to cause you slight clearance issues with brand new pads.
They should stop rubbing so badly once bedded in and slightly worn.
reset the calipers once you've used them for a ride (or two)

I guess sram went thicker with their new massive rotors to help stiffen them?
 

salko

E*POWAH Elite World Champion
Aug 29, 2019
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Yes, I pushed back the pistons using bleed block and then slightly untightened bleed port screw on lever and a few drops came out ...
I'm not sure if thicker rotor is a problem while I had more than enough clearance (~1mm on each side) after resetting the pistons. It just fells like the piston action stroke could be a bit longer as there is still plenty of space for lever stroke ...
AFAIK all 220mm rotors are 2mm thick, not just SRAM ...
 

slippery pete

Well-known member
Oct 29, 2019
160
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Scotland
If the pistons push back sufficiently to leave a 1mm clearance and then adjust in when you operate them, they are not overfilled.

Possibly you have a sticky piston and they're pushing the rotor off to one side as the pistons that aren't stuck make contact. This will also give a longer than wanted lever action and some vagueness in the feel.

Cleaning away any residual brake dust and muck at the caliper is a good start. You should do this with the pistons pushed out a little bit. I prefer cleanliness to any suggestion to lube pistons as using brake fluid to lube is going to attract dust and repeat the problem.

In my experience codes tend to be bad for this and not necessarily always dirty but maybe some manufacturing surface finish/tolerance also involved. They can take time to bed. In the meantime, having pumped them close to the rotor you can do some caliper repositioning to minimise rub. You won't necessarily get them rub free but they can be ok.

The dynamics of multi piston brake caliper function are somewhat subtle and it is worse the more pistons that are involved. Better implementations tend to be those with different sized pistons like the codes. Be patient unless your set are absurdly bad they will get better if they get a cleaning from time to time.
 

paquo

Well-known member
Jul 31, 2018
463
282
usa
i tried to fit a 220 and had the same problem, i didn't even try to fix. Anyway if you continue having problems consider using a very slight shim on the bleed block to give the pads more room. I had the opposite problem with first gen mt8
 

salko

E*POWAH Elite World Champion
Aug 29, 2019
1,235
835
SLO
I don't quite understand, what do you think this very slight shim on the bleed block will do after I pump the lever?
 

salko

E*POWAH Elite World Champion
Aug 29, 2019
1,235
835
SLO
I had to shorten front brake hose and route new rear brake hose through the frame, so I obviously needed to bleed the brakes. After bleeding it seems like the clearance between pads and rotor increased slightly, just enough that there is no more rub. :cool:
 

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