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2x10 Front Mech Issues - Boardman Pro

R-PointR-Point Posts: 10
edited June 2012 in MTB workshop & tech
I am having some issues with the chain rubbing on the front derailler in the high gears. If I adjust the H screw so the chain doesn't rub on the outer side of the mech when in the highest gear on the cassette, when I change to the lowest gear on the cassette (still high on the chainring) the chain rubs on the inside of the front mech. Any tips on what to do here?

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    High gears?
    In which ring on the front.

    Adjusting the stops is normally the last thing to do after having adjusted the tension.

    Read the setup info on park tools and start from the beginning.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • R-PointR-Point Posts: 10
    Biggest ring on the front.
  • Chunkers1980Chunkers1980 Posts: 8,035
    H screw has very little to do with it. Infact it may be best without it making any difference at all until it goes where it should.
  • oxocube1oxocube1 Posts: 651
    I personally would not suggest to be riding the bike in 2 on the front and the lowest gear on the back. The 42t outer ring you get on the chainset combined with the 36t big ring on the cassette fully stretches the chain and will likely cause premature wear on any one of the chain/cassette/chainset, as i have seen the exact same bike in the shop with a customer having similar issues. It puts unnecessary stress on the drivetrain and usually makes the rear mech click too. If you need a lower gear you can just drop onto the 1st gear on the front.

    The 10 speed mechs are designed to run with the 10 speed chains, both of which are thinner than regular (7,8,9) speed components, so there will be rub on the inner side of the mech in the two largest gears and most likely rub on the outer side of the mech in the two smallest gears.
  • Chunkers1980Chunkers1980 Posts: 8,035
    Er 2x. Most would only run 40t max. 2x means you can run all 16, 18, 20 or 22 gears
  • nicklousenicklouse Posts: 81,520 Lives Here
    R-Point wrote:
    Biggest ring on the front.
    High gears? Small sized cogs?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • oxocube1oxocube1 Posts: 651
    Er 2x. Most would only run 40t max. 2x means you can run all 16, 18, 20 or 22 gears

    Yea that's what you would expect, but the FSA Comet chainsets that come on the boardman pros use 42t,27t chainrings. A little unusual i know. And they shorten the chain a little too much for my liking. They should leave the chain long enough for a front triple, but just still use the 2x10. That way the lower gears on the rear are not a stretch when on the big ring at the front.
  • R-PointR-Point Posts: 10
    Thanks very much for the tips guys. So is the chain on the bike not a proper 10 speed chain then, if it's width is causing the rubbing issues? Would a thinner and longer chain cure the problems?

    I'll just adjust it so it doesn't rub in the highest gear, and avoid the big front, big rear combo. But it's a little annoying, as I thought the whole point of a 10 speed setup was to provide the full spread of gears without chainline problems.
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