SLX brakes free stroke

marcarm
marcarm Posts: 134
edited September 2018 in MTB workshop & tech
I have SLX brakes (M675 I think) on my new (to me) Canyon, I have just put new pads in and just bed them in tonight.

I notice that I have a lot of movement in the lever before the pads engage, I never had this with my previous bike with Guide R's, but now I have to move the lever about an inch before I get any braking, the tips of the levers are nearly at my middle finger knuckles if I want to come to a sudden stop, as I need the levers quite close to be able to reach them comfortably.

I don't believe the SLX has free stroke adjustment like the XT brakes, is there anything I can do to adjust this?

They are not spongy so don't think they need a bleed, that's not something I have done myself before but it looks simple enough to do with the right kit.

Comments

  • If have SLX and XT on both bikes. SLX do not have free stroke adjustment and it's not that great anyway on the XT.

    I recently had the same issue as you with my XT brakes. I actually bled them with bleed blocks in place and they were nice and tight. Take the blocks out and insert wheel and I get a lot of slack before they engage as the rotor is thinner than the bleed blocks.

    I did 2 things.

    1. Bleed the brakes with something between the pads that is slightly wider by about 1mm than your rotors. This should set your pads much closer to your rotors and remove some of the slack. Even if they aren't spongy, a bleed will top up the system and push the pistons/pads closer to the rotors. Dirty/old fluid doesn't help and it's always good to have a good purge once in a while.

    2. Fit new rotors. Having tried option 1 a couple of times with no real benefit I measured my rotors. They were quite worn (hard to tell with the naked eye). When I fitted new pads, they were naturally closer to the rotors and the slack disappeared. Once they bedded in, I now have much quicker engagement and the brakes are how I want them.

    Wierdly, my SLX have always been pretty much spot on, so try a bleed and see how you get on.

    I'm not saying this is the right solution, but it worked for me.
    "Ride, crash, replace"
  • cooldad
    cooldad Posts: 32,599
    Don't faff with bleeding unless they are spongy.

    Stick a rubber band over each lever around the bars overnight and see what happens.
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  • marcarm
    marcarm Posts: 134
    Thanks, i'll go with the rubber band method before trying anything else.

    Does it have to be a band? ie something that is elastic? Or can I tape/ziptie them them, which of course is a lot firmer than a band.
  • cooldad
    cooldad Posts: 32,599
    Just to hold the brakes on for a while. Anything.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools