Worth upgrading rim brakes to disc?

nbuuifx
nbuuifx Posts: 302
edited December 2018 in MTB workshop & tech
On a Rockhopper with rim brakes, is it worth fitting some hydraulic disc brakes?

The frame looks to have disc brake mounts as does the rear wheel

Comments

  • cooldad
    cooldad Posts: 32,599
    Or just buy a bike with them already on. As decent brakes will cost more than that bike is worth.

    But in answer, decent hydraulics are streets ahead of Vs.
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  • Yes - disc brakes work better. Some basic Shimano brakes would do a good job.
    "Ride, crash, replace"
  • steve_sordy
    steve_sordy Posts: 2,452
    Even cable disc brakes are much, much, better than rim brakes on an mtb.
    But hydraulic disc brakes are the way to go, virtually maintenance free.
  • You might as well, they are a good upgrade and I 'd say they were pretty cheap.

    I got some m505 brakes for £22 posted on the bay, they work really well, maybe another £10 for a set a disc and you are good to go.

    https://www.ebay.co.uk/itm/shimano-deore-brakes/254020940732?hash=item3b24d3f3bc:g:ZfsAAOSwa6NcDtdq:rk:6:pf:0

    This could be a cheap upgrade but you need to know the length of the hoses so they fit on your bike.
    You can cut hoses down if needed though, with the right parts and tools.
  • nbuuifx
    nbuuifx Posts: 302
    Thanks for this,

    Would the 535s posted above be a direct fit? (providing hoses are the correct length?)

    Also how do I know what size discs would be best? Does it matter if I mix makes?
  • cooldad
    cooldad Posts: 32,599
    Depends on the fittings on your frame and forks. Brakes look like post mount. The bike you were looking at look like IS mounts, so would need adaptors.
    For the type of bike and riding you mentioned, 160mm would be more than enough.
    Make of rotors makes no difference as long as they match the size of the adaptors /mounts etc. And wheels, either 6 bolt or splined.
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  • cougie
    cougie Posts: 22,512
    +1 on this. Either live with what you have or get a new bike. Upgrading is an expensive and tricky business and you may end up with worse brakes.
  • nbuuifx
    nbuuifx Posts: 302
    Thanks for the info. I think I'll stick with the v brakes to start with. It just seemed an obvious upgrade given that all the mounts are there. I have a spare set of wheels with rotors on too so just need the brakes themselves for now. I'll keep my eye out for some sub £20 disc brakes. I'll don't think I'll buy new pads for the v brakes, so when these wear out I'll make the jump to disc if I haven't before then.

    You are right that I the bike is IS mount. The 535 ones above were post mount so I would need adapters but I take it that is fairly straightforward?

    I like messing with bits like this too, as you learn so much from it! I find my chances of fixing things at the road side is much higher if I've put the bits on, or had to replace them before!
  • ednino
    ednino Posts: 684
    Yes, in the wet and mud disc brakes are 10000 times better
  • The shimano calipers are POST mount and your frame is I.S (International standard) so you would need

    Post to I.S mount 160mm adapters

    Shimano call them - FS MA F160 - the front and rear are different, the 160 is for 160mm disc so if you had 180mm disc it would be a F180.

    https://www.ebay.co.uk/itm/160-180mm-Front-Rear-Disc-Brake-Adapter-Caliper-Post-Mount-PM-to-IS-Standard/283218168156?epid=1081963134&hash=item41f11e495c:m:m6XICK3Vi1GNTmwgGOs4Siw:rk:2:pf:0
  • nbuuifx
    nbuuifx Posts: 302
    I ended up getting some 535 disc brakes so just need to figure out the fitting. I have some spare wheels with 160mm calipers. So I just need the is to post mount adapters.

    Are the ones in the link correct for both front and rear? Are they definitely the right way. As in are they for putting post mount brakes on an IS frame?
  • The Rookie
    The Rookie Posts: 27,812
    Depends what size discs are on the wheels, and they are........?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • nbuuifx
    nbuuifx Posts: 302
    The discs are 160mm
  • nbuuifx
    nbuuifx Posts: 302
    Right, I got the adapters and the brakes and they all seem to line up pretty well.

    The only thing I am missing is the bolts that bolt the caliper to the adapter. Do I need to buy any particular special ones or would any bolt do?
  • cooldad
    cooldad Posts: 32,599
    They need to be the right size - thread and length.
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  • nbuuifx
    nbuuifx Posts: 302
    cooldad wrote:
    They need to be the right size - thread and length.

    I realise that, they are a M6 thread. Allen head. The adapter to frame bolts are 18mm long and that looks about right for the calipers.

    What I meant by my question was do they need to be any particular material or a certain tensile strength? Can you just buy the bolts easy enough? I had a quick search but struggled to find them but then I might not be quite searching for the right thing
  • nbuuifx
    nbuuifx Posts: 302
    Excellent, thank you
  • nbuuifx
    nbuuifx Posts: 302
    It has taken a long time, it is on the wife's bike so never quite made the priority list 🤣

    However I've finally done it. I wish I'd done it sooner! It didn't take long at all. Simple plug and play bolt on solution. The front brake is spot on the back brake works but is a bit soft so probably needs bleeding. Even soft it is a lot better than the old brakes.

    Thanks again to those that helped! I can't believe all the bits have been sitting on the garage shelves for 18 months!



  • steve_sordy
    steve_sordy Posts: 2,452
    edited June 2020
    One thing you might not realise, seeing as this is your first foray into disc brakes. The pads and discs need "bedding in". If you don't do this the brakes will never be as good as they can be. You should be able to stand the bike on its nose with little effort, and I'm not joking!

    https://www.youtube.com/watch?v=BWQxGzHQZVU
  • nbuuifx
    nbuuifx Posts: 302

    One thing you might not realise, seeing as this is your first foray into disc brakes. The pads and discs need "bedding in". If you don't do this the brakes will never be as good as they can be. You should be able to stand the bike on its nose with little effort, and I'm not joking!

    https://www.youtube.com/watch?v=BWQxGzHQZVU

    Thanks for this. I do have disc brakes on my MTB as well but am constantly learning! These are all second hand parts that have gone into my wife's bike so hopefully don't need much bedding in but will use it on my MTB as I have just put new pads on that one.

    Thanks again!