Bicycle Disc Brakes - Advice Please

Discussion in 'General Chat' started by nheather, Feb 8, 2009.

  1. nheather

    nheather
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    I'd like to upgrade the brakes on my bicycle to disc brakes.

    My bike is about 4 years old now, it is a Specialized Rockhopper and is currently fitted with V-Brakes.

    It has the mounting points on the wheels and on the posts, so it should be just a case of screwing the rotors and calipers on and replacing the levers.

    The bit I'm not sure about is rotor size.

    I've seen sets for sale with rotors ranging from 160mm upto 203mm.

    I'm assuming the bigger ones have more stopping power.

    Does this mean that I can choose to fit any size to my cycle or will there be a specific size to fit my bike?

    Cheers,

    Nigel
     
  2. montybaber

    montybaber
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    have you ever used disk brakes?

    I have always been dissapointed by their stopping power, i think you can go any size :)
     
  3. nheather

    nheather
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    I had assumed that they would have more stopping power.

    I'm looking an hydraulic rather than mechanical - I've heard the mechanical ones are no better, maybe worse, than V-Brakes.

    Obviously they should be better in conditions where the rims are getting wet or muddy - but that is not necessary the case for my cycling.

    Cheers,

    Nigel
     
  4. captainff

    captainff
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    AFAIK larger rotors give better stopping power over a longer time because they can dissipate the heat generated quicker than smaller rotors.

    Each fork will have an optimum size of rotor and you may need adapter plates to accomodate a larger one.
     
  5. montybaber

    montybaber
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    Agreed about wet and muddy but in dry conditions I felt very little difference from my v brakes (hydraulic)

    I was hugely dissapointed BOTH times on different setups, my advice is test ride a bike with disks before investing to see what you think

    I have mates who swear by them but then they already have them lol
     
  6. Dave Weystoner

    Dave Weystoner
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    I've fitted hydraulic disc brakes to friends' bikes, but never used them myself (no mounts on my bike). They're a bit fiddly to set up, but I've not heard any complaints about use or stopping power. The big plus is they don't get clogged in mud like rim brakes, unless you're in the real deep stuff!

    Dave
     
  7. eL-ZilCHo!

    eL-ZilCHo!
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    Discs are MUCH better than V's if you bother to set them up properley.

    I'd recomend Hope brakes, if they're still going. (been a while since I used my bike. I have Hope mono minis and they are very good.

    As for sizing, depends what you use your bike for. The larger the rotor the better the stopping power, however you should remember the larger the rotor the further out the caliper sits, thus applying a higher moment on the forks, seatstay.

    With that in mind, I'd probably go 180mm for the front and 160mm for the rear. Which is exactly the set-up I have on my bike. Should provide good all round stopping power.
     
  8. nheather

    nheather
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    This is exactly why I asked the question. The bit that puzzles me is that the brake units mount onto tabs molded on the forks\stays so isn't their position fixed. And if they are fixed, how can they accomodate different sized rotors.

    btw - I know that Hope units don't have the IS standard fittings.

    Cheers,

    Nigel
     
  9. Alan Westy

    Alan Westy
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    Personally I've never seen the point in them, ordinary rim brakes are effectively disc brakes aren't they, but the point of contact is at a bigger radius so should be more effective.
     
  10. Bill Hicks

    Bill Hicks
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    I bought a ATB a year ago that had disc's at the front & brake pads at the back.
    Believe me I wish they were pads at the front as well!

    I've tried setting them up, but they just revert back to their usual uselessness within minutes!

    Waste of time.
     
  11. Desmo

    Desmo
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    Discs are great as long as they're set up properly. I've got Hope minis on mine and they almost threw me over the bars first time I used them in anger :rotfl:
     
  12. figoagogo

    figoagogo
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    My V-brakes do that on my Specialized!

    OP - I have the same bike as you, and has similar thoughts about upgrading. However is it worth it, I presume you need new wheels/hubs (?), brakes, levers what does that all add up to? £250+ or am I way out?

    I gave up on the idea as I rarely get the chance to ride properly, as I am more likely to out with the wife and kids :)
     
  13. nheather

    nheather
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    The hubs, forks and stays are already disc compatible.

    So I would need

    Rotors
    Brake Units
    Levers
    Hydraulic Pipework

    Buying as complete kits I would be looking at

    £100 to £150 depending on spec (by which I mean the spec that I would consider - obviously you can pay a lot more).

    But I am beginning to think why bother - my V-Brakes are pretty good and they've never let me down.

    Just a case of upgraditis and shiny new toys.

    Cheers,

    Nigel
     
  14. figoagogo

    figoagogo
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    I am happy with V-brakes, my only issue is they can wear the rims down.
     
  15. captainff

    captainff
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    A common affliction for bike riders :rotfl:
     
  16. montybaber

    montybaber
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    what amuses me is every rider i know who have every upgraded (usually the ones with every new item on the market) swear by them, every rider who has got them standard with a new bike or v brake users believe them to be no better than v's lol

    If it makes yourself feel better than go on then they are better :rolleyes:

    seriously though I couldnt feel any difference and i was fully expecting to be thrown over the bars, they were noisy too!

    his were juicy 3's not sure on the others
     
  17. shil

    shil
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    What type of riding do you do? If you do more cross country rather than road go for a 180mm up front and a 160 up back. I have a set of Hope Mono Minis on my XC and they're superb for mild XC. I've even used Mono Minis on my Rigid Freeride rig and they're still great! As already mentioned you can go to any size. If you go for disc system go for hydraulic kit rather than cable run. Much better lever modulation and power.

    Another advantage of discs is less contamination from mud/water etc... Your front fork will detemine which caliper you need (most are international standards) and mounting kits. Plus if you go up in rotor size you may need a larger caliper mounting bracket and it is a straight forward swap. :thumbsup:
     
  18. eL-ZilCHo!

    eL-ZilCHo!
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    They just stick out further and at a different angle. If they are IS mount any IS caliper will fit.

    Don't they? Ignore me then. Mine are IS, do they have those post mounts now? Must have changed them since I bought them. (Haven't used my bike for a few years.. keep meaning too, but I'm getting lazier by the day!)
     
  19. HotblackDesiato

    HotblackDesiato
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    The juicy 3s came as stock on my Cannondale, they're pretty weak and very noisy, will be the first things i change.
     
  20. nheather

    nheather
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    That's worth knowing. The Juicy's were on my 'consider list' because that it was comes as standard on the new Specialized Rockhoppers (they don't do a V-Brake version any more).

    The Juicy 3's (possibly the 5's) were within in my budget but sounds like I should just stick with my V-Brakes.

    Cheers,

    Nigel
     
  21. Aerojon

    Aerojon
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    Mines got discs front/rear,i find they've got slightly better stopping power than normal brakes in the dry.In the wet there better,i just apply them every now & again just to keep the discs dry..imo they are better in the wet than normal brakes..

    i've had both types..:smashin:
     

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