Forum home Mountain biking forum MTB workshop & tech

Brake upgrades

Derg34Derg34 Posts: 3
edited September 2018 in MTB workshop & tech
Hello all, my 1st post here.

I currently have shimano slx m675 brakes fitted to my bike with 180mm discs front and rear. I ride a lot in the tweed valley including the tweedlove enduros.

My discs are almost at the minimum thickness and I ran the rear pads down to the metal at the golfie earlier this year, now even with new pads the brakes don't feel quite as good as they were but even when they were working their best I felt like they just weren't quite up to the long descents ( although that may just be me being a wimp on the super steep stuff).

I'm wondering what my options are for beefing them up a bit without replacing the whole system. Can I fit better calipers to the existing system? Would a bigger disc on the front make much difference? Are there better pads than the standard bo1s ones? Or should I just stick with standard new parts and a good clean up and bleed unless I can afford a full new system?

Any info is much appreciated.




  • slc123slc123 Posts: 407
    How do you feel they are lacking? Slow to respond? Not giving you the braking power at high speeds?

    A good bleed and maintenance will definitely help. Bigger discs will improve stopping power but you will likely need adapters to fit them.
    Cannondale Trail 27.5 | 2015
    Titus El Chulo 27.5 | 2017
    Trek Slash 9 27.5 | 2015 (building)
  • cooldadcooldad Posts: 32,904
    Try decent pads (Uberbike have quite a decent range - I use Race Matrix.

    And if the rotors are worn, new rotors.

    And a bleed if they are spongy.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

  • steve_sordysteve_sordy Posts: 2,025
    edited September 2018
    Are you a heavy guy? If so, your weight may be too much for the brakes.

    To give you something to work with, I have one bike that is 180 mm F&R and the brakes are absolutely fine. The other bike is 200 mm F&R, also fine but I have to be careful not to grab the levers. But the brakes are specced for what the bikes were intended for. The first is a trail bike, the second is an Enduro bike. I weigh 14.5 stone in my riding gear.
  • Thanks for the quick replies.

    I'm about 12 stone. I just find the bike takes a while to slow down on the steep descents a bit like the pads aren't fully bed in. They bite pretty quick and seem to feel ok most of the time. To be honest I don't think I had a problem when I 1st got the bike so might just go for new discs, better pads and another bleed.

    Thanks for replies.
  • david7mdavid7m Posts: 636
    +1 on the Uber Race Matrix!
    I fitted a set on the front last month and they are awesome. You can literally hear them biting into the disc and they were perfect last weekend at BPW.
    Try a set, about £10. Cheaper than rotors etc.
  • 02GF7402GF74 Posts: 1,294
    I'm heavier than sordy and ride xc with 160/160 rotors. I'm not crazy downhiller and it works well for me..

    I doubt slx brakes are the limiting factor so do the cheap and simple things first...
    Fit new pads as these are worn.
    Fit new discs, going up in size on front, will need adapter..

    Bleed brakes and replace fluid.

    Should be a noticeable improvement.
  • 02GF7402GF74 Posts: 1,294
    Just noticed you have 180/180 already so that should ample for 12st.

    I found that disc design makes a big difference in stopping power, lightweight disc with big holes in the braking surface arent great.

    Best value 6 bolt disc is avid g3 clone, light ish and stop well.
  • I have the same brakes on my HT and that's been thrown down BPW, Cwmcarn and a few other places. I think they are really good. Never had much brake fade.

    I have 180F and 160R. For what you want to do 180/180 should be fine.

    I have XT M8000 on my FS (also 180/160) and they didn't seem to have the same power, more or less what you describe. Repeated attempts to bleed and new pads didn't help. I solved it by changing rotors - the pads just were having to travel too far to make contact (despite my best efforts to set them closer to the rotors), I just didn't get the power. It wasn't obvious but with new rotors the brake have been transformed and are back to their best (the brakes were 6m old but the rotors were 3+ years old).

    I almost prefer my SLX over the XT as I can't see much difference between them.

    I use sintered pads F & R and tend to use Clarkes, although I do have some Uberbike ones that I've not tried yet. Everyone has their favourites.

    For rotors, I found Clarkes to be pretty good. I laso have a Chinese version thaty look exactly the same but slightly cheaper. Only time will tell if they are cost effective.

    I'd suggest changing rotors and a bleed. Another benefit of the SLX is that they are dead easy to service. Once you've done that (and bedded in new rotros and pads), I reckon you'd be about right.
    "Ride, crash, replace"
  • swod1swod1 Posts: 1,639
    I’d say try some new discs first.

    Were you using metal pads previously?

    New discs and pads inexpensive to try and then look into other options
  • bobbydigitalbobbydigital Posts: 249
    edited October 2018
    If pads have too far to travel to make contact you can try,

    Removing caliper
    Pump brake (to bring pads closer)
    Reinstall caliper.

    This way the pistons are now set closer to the disc to begin with and level lever travel is the result.
  • jamskijamski Posts: 737
    Another vote for Uberbike Race Matrix here, great pads. I found my M6000 brakes lacking from cold, took a while for that initial bike to kick in, but now they bite brilliantly from cold. I'm a similar weight and run 200/180. Works well enough for me. :)

    Oh, and mine are the finned ones, should help with long decents next month in Wales. :)
    Daddy, Husband, Designer, Biker, Gamer, Geek
    Bird Aeris 120 | Boardman Team 650b | Boardman Pro FS | Calibre Two.two
Sign In or Register to comment.