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  1. #1
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    Rotor sizing question, do I need them this large?

    My Large Camber expert comes stock with 203 front and 185 rear G3 cleansweeps and the Elixir 5's. I've not been real happy with the brakes, plenty of power but low on the modulation and feedback, since I got the bike.

    This weekend on a ride with some guys I met at the trail I noticed out of all 4 bikes mine had the largest rotors, One guy was running 160 fr/rr but the other 2 bikes, both full squish bikes, were running 185 front with a 160 rear on Avid Elixirs. One bike in particular was a current model Giant Anthem 3 with Elixirs, I think they were 3's, and running 185/160 on it.

    Why does the Camber come with larger brakes than a comparable bike and is it too much, any reason I shouldn't try a 185 fr/rr?

    Also, the 203 front adaptor is tiny, looks like if I remove it I could just attach the caliper to the post mount without an adaptor and it might fit a 180 or 185 rotor, does this sound right? Its a stock Reba on a 2011 Camber expert.
    Hardrock 29er, Niner EMD9, Cannondale F29, Camber Expert, 650b Nickel all gone.
    2014 Giant Anthem 27.5 here.

  2. #2
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    I doubt your fork posts will allow you to run 185 front with no adapter, but there's an easy way to find out: take the 185 off the back, put it on the front, remove the front adapter, and see if everything lines up.

  3. #3
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    On a big downhill you may see why 203mm works!!
    The disc prevents fading, for sure (Better cooloing) - I changed from 160>180>203, happy now!
    Given the cost, and the miniscule weight gain, why degrade?

  4. #4
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    Quote Originally Posted by stevepratt48 View Post
    On a big downhill you may see why 203mm works!!
    The disc prevents fading, for sure (Better cooloing) - I changed from 160>180>203, happy now!
    Given the cost, and the miniscule weight gain, why degrade?
    OP indicated that he didn't like the binary on-off nature of his brakes. I think he was hoping to actually reduce the power a little bit in exchange for better modulation.

  5. #5
    rebmem rbtm
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    Quote Originally Posted by madsedan View Post
    Also, the 203 front adaptor is tiny, looks like if I remove it I could just attach the caliper to the post mount without an adaptor and it might fit a 180 or 185 rotor, does this sound right? Its a stock Reba on a 2011 Camber expert.
    Avid Front Post Mount Adaptor 185mm

    Avid Front Post Mount Adaptor 203mm

  6. #6
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    I know all about long downhill heat dissipation, etc. but I live in Texas, we simply don't ride much like that around the area. Sounds like the general consensus is to stay with what I have so I'll keep the size and juts buy new rotors, going to go with either HS1's or Alligator Windcutters.
    Hardrock 29er, Niner EMD9, Cannondale F29, Camber Expert, 650b Nickel all gone.
    2014 Giant Anthem 27.5 here.

  7. #7
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    Unless you've got a brake rotor related issue (like warped rotors / vibration / excessive noise etc) then there's probably not much point replacing your Avid G3 clean sweep rotors with different rotors of the same size.

    I'd try going down to a set of 180mm F / 160mm R brake rotors. You could probably go down to 160mm F / 160mm R brake rotors if you aren't doing much in the way of long descents.

    You could also try replacing the stock Avid semi-metallic brake pads with organic compound brake pads at the same time. That can soften the brake feel a bit which could help with modulation and feel too.

  8. #8
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    Quote Originally Posted by madsedan View Post
    My Large Camber expert comes stock with 203 front and 185 rear G3 cleansweeps and the Elixir 5's. I've not been real happy with the brakes, plenty of power but low on the modulation and feedback, since I got the bike.
    I'd bet it's more to do with the Elixir 5's than anything. Have a set of BB7's laying around? Every hydro brake I've tried is a total light switch, my mech brakes have much better feel and modulation.

  9. #9
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    Quote Originally Posted by WR304 View Post
    Unless you've got a brake rotor related issue (like warped rotors / vibration / excessive noise etc) then there's probably not much point replacing your Avid G3 clean sweep rotors with different rotors of the same size.

    I'd try going down to a set of 180mm F / 160mm R brake rotors. You could probably go down to 160mm F / 160mm R brake rotors if you aren't doing much in the way of long descents.

    You could also try replacing the stock Avid semi-metallic brake pads with organic compound brake pads at the same time. That can soften the brake feel a bit which could help with modulation and feel too.
    I agree 100%. Rotor type really don't make too much of a different in terms of modulation and power; size matters more (as always... ). I'd try those Alligator rotors since they do help. I'm running those as well, 180/160 and I love it. So yeah, get new rotors 180/160. Maybe you can even try the classifieds here and posting a For Trade or wanted ad. If a rotor change doesn't help, you can try different pads as well. I do like the organic pads with my XX brake, but they wear rather fast and are probably sorta expensive. On the plus side, they're lighter and dead silent. One more thing: Are the pads really close to the rotors? Try taking your wheel off and getting one of the Avid pad spacers to reset the pad spacing. It could be that the pads are running too close to the rotors and engaging too quickly.

    Quote Originally Posted by RCook View Post
    I'd bet it's more to do with the Elixir 5's than anything. Have a set of BB7's laying around? Every hydro brake I've tried is a total light switch, my mech brakes have much better feel and modulation.
    That's a bit of a generalization don't you think? I've tried BB7, BB5, and Hayes mechs, along with XT hydros, Elixir R and XX. Not counting the BB5 which was set up terribly and barely worked (and I didn't bother to fix), they all worked great set up right. All the hydros had great modulation set up right. The mineral oil system in the XT have really good modulation, but a bit less power (these were the older M760). The XX have amazing modulation really, I can even brake at the edge of traction with the back brake and have total control. The R also was pretty good (after I reset the pad spacing). As for the mechs, I felt the cable friction and spring friction, even with decent cables and housing, got slightly in the way of modulation and feel. Cables really can't match fluids in hoses. But it was always linear and depended on setup as well.

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