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Bike 'Flex' and Gears

PAD20959PAD20959 Posts: 109
edited January 2011 in MTB workshop & tech
Hopefully a simple question with a simple answer forthcoming.

I'm 15st and ride a Boardman HT Pro. Would me pedalling with any degree of force be enough to flex the frame and subsequently allow the rear derailleur to hop between gears?

Pierre
Orange Five 2010
Specialized Carve Pro 2013
Specialized Epic Expert Carbon 2014

Posts

  • *AJ**AJ* Posts: 1,080
    on a hardtail? No way....
  • peter413peter413 Posts: 5,120
    On a hardtail, possibly, more likely your drivetrain is worn out or your mech isn't setup correctly
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  • PAD20959PAD20959 Posts: 109
    The whole bike, and therefore drivetrain, is relatively new (Oct 2010) and has been on 7 off road rides in that time. Thought it would be the rear mech adjustment, but somebody mentioned the frame flex as a possibility (but not really with any conviction, just as an idea).

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • bennett_346bennett_346 Posts: 5,029
    Cable stretch most likely, judging by the length of time you've had it. Re-index the gears properly.
  • PAD20959PAD20959 Posts: 109
    Thanks bennett_346. I did have the 6 week service done, but I guess there hasn't been enough riding to get the stretch fully out. It's back with Halfords now, so hopefully they will sort it out.

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • bennett_346bennett_346 Posts: 5,029
    PAD20959 wrote:
    Thanks bennett_346. I did have the 6 week service done, but I guess there hasn't been enough riding to get the stretch fully out. It's back with Halfords now, so hopefully they will sort it out.

    Pierre
    Re-indexing gears is a simple thing thats well worth learning to do yourself as you may be looking at doing it fairly often. Plenty of good youtube videos, have fun.
  • PAD20959PAD20959 Posts: 109
    I have a lack of space and bike stand, so not sure how easy or practical it would be. Will definitely have a look though. Thanks.

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • The RookieThe Rookie Posts: 27,802
    No need for a stand to index gears (though it makes it easier), I usually do it on the patio or in the utility if its cold out and the wife is out!

    Simon
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • cavegiantcavegiant Posts: 1,546
    I have not ridden that frame but I have had that issue with quite a few bikes.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?
  • AnonymousAnonymous Posts: 79,667
    PAD20959 wrote:
    I have a lack of space and bike stand, so not sure how easy or practical it would be. Will definitely have a look though. Thanks.

    Pierre
    You can index the gears when the bike is upside down on the ground. Pedal it with one hand whilst adjusting the rear mech with the other.
  • GHillGHill Posts: 2,402
    Often a quick turn of the barrel adjusters can sort you out (there's one at the shifters, and often one at the rear mech). You don't need much space for it :wink:
  • PAD20959PAD20959 Posts: 109
    All sounds like good advice guys, thank you. I'll look at getting a book or looking at YouTube for how to Index the gears. I'll leave it to Halfords this time around though!

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • leafliteleaflite Posts: 1,651
    Or could it be a bent rear hanger?

    I had this problem with my gt, and halfords actually had a tool to straighten it out.
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  • PAD20959PAD20959 Posts: 109
    The Boardman HT Pro has an SRAM X0 rear mech, I take it this would be subject to bending as it's carbon?

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • AnonymousAnonymous Posts: 79,667
    PAD20959 wrote:
    The Boardman HT Pro has an SRAM X0 rear mech, I take it this would be subject to bending as it's carbon?

    Pierre
    No, not at all. Carbon is stiffer than metals.
  • captainflycaptainfly Posts: 1,001
    PAD20959 wrote:
    Thanks bennett_346. I did have the 6 week service done, but I guess there hasn't been enough riding to get the stretch fully out. It's back with Halfords now, so hopefully they will sort it out.

    Pierre

    Halfords service? Depending on branch that can do more harm than good :roll:

    I'd try some agjustment of the barrel adjusters, do it slowly while riding somewhere smooth and quiet.
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  • PAD20959PAD20959 Posts: 109
    I know the rep that Halfords have, but I have a years free servicing with the bike I got. So I'm happy to let them fettle until they prove themselves inept.

    Pierre
    Orange Five 2010
    Specialized Carve Pro 2013
    Specialized Epic Expert Carbon 2014
  • bails87bails87 Posts: 12,998
    My local halfords are fine. As others have said, learn how to sort it. If it goes a bit wrong while you're out on a ride it's better to just be able to tweak it there and then than to have to finish the ride with jumping gears.
    MTB/CX

    "As I said last time, it won't happen again."
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