SLX Brakes

[Frank.Hutt]

I got lucky with SLX brake set on special CWC.....upgrade bug has bitten.

I don't have a problem with the install or anything just some advice on the rotors..

I currently have the BR-M355 brakes with the SM-RT30 rotors and just wanted to change the caliper and brakes and retain the same rotors. On downloading the Shimano manual for component compatibility I saw that the recommendation is to use the narrow type rotor instead of the wide type: 

 

http://productinfo.shimano.com/#/lc/2.0

 

So ...has anyone used SLX/XT brake calipers with the wide (lower end) rotors?

Does the wide and narrow rotor make a difference?

 

have been to 3 lbs and they don't have an answer - at least no-one tried to convince me to buy the narrow type rotors - as what the result of using the SLX brake with the wide rotor would be.

[NukeproofPeanut]

Are you referring to this section?

SM-RT68
CENTER LOCK
ICE-TECHNOLOGIES
203mm
180mm
160mm

SM-RT81
CENTER LOCK
ICE-TECHNOLOGIES
140mm (Rear only)

SM-RT66
6-bolt type
203mm
180mm
160mm

SM-RTAD05
Disc brake rotor adapter

 

 

And by narrower, do you mean smaller, 160mm as opposed to 180mm diameter? Or actual cross section? I'd think a thicker rotor is better, more material to wear through, less chance of warping etc.

[johanpre44]

I got lucky with SLX brake set on special CWC.....upgrade bug has bitten.

I don't have a problem with the install or anything just some advice on the rotors..

I currently have the BR-M355 brakes with the SM-RT30 rotors and just wanted to change the caliper and brakes and retain the same rotors. On downloading the Shimano manual for component compatibility I saw that the recommendation is to use the narrow type rotor instead of the wide type: 

 

http://productinfo.shimano.com/#/lc/2.0

 

So ...has anyone used SLX/XT brake calipers with the wide (lower end) rotors?

Does the wide and narrow rotor make a difference?

 

have been to 3 lbs and they don't have an answer - at least no-one tried to convince me to buy the narrow type rotors - as what the result of using the SLX brake with the wide rotor would be.

I have noticed this on Shimano's documents as well. Deore brakes and up requires a Narrower braking surface compared to the Alivio and lower brakes. This is apparent when you look at the brake pad shape G01A (for Deore and up) and B01S (for Alivio and lower).

 

I guess best will be to follow Shimano's recommendation but I don't think it will cause any problem when you run the SLX brakes on the RT30 rotors except for wear that will not be spread over the entire wider braking surface because of the narrower brake pad. I also expect the breaking performance to be on par with the narrow (RT64) discs. Another difference between the RT64 discs and RT30 is that the lower end discs can usually only be used with Resin pads (and not metal).

Edited May 26, 2015 by johanpre44

[velomonatiCT]

I run upgraded deore brakes with G01A pads on my older (wide) rotors haven't had any problems at all even though as above I shouldn't according to shimano

 

I agree about some low end rotors being only for resin pads but I doubt you will have any trouble with RT30 s

[Frank.Hutt]

Thanks for the responses - helpful all.

I got some narrow rotors from a fellow hubber so am playing it safe for now.

[NukeproofPeanut]

I had no idea there were wider or narrower brake disks, I thought it was all "standard". 

[Bobbo_SA]

*snip* Another difference between the RT64 discs and RT30 is that the lower end discs can usually only be used with Resin pads (and not metal).

 

Although the rotor states "Resin Pads Only", i have run the rotors before with metal pads without any issues, although I'm sure in the long term (I only went through 2 sets of metal pads before selling the brakes + rotors) these discs would wear quicker, but it would still be years worth of casual riding.