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Bent crankset?

chrisrahi9chrisrahi9 Posts: 41
edited March 2017 in MTB general
Hello!

About a month ago i bought an enduro bike. After one week i noticed that the chain wasn't spinning and that it was rubbing against the front mech. At first i thought it was a problem with a derailleur and that it needed adjustment. But then i realized that the problem was with the chainring itself because the chain wobbled at one place and then continued normally (it did that each pedal turned). So i was sure that maybe one of the teeth was bent. I contacted the maker and explained the problem and they sent a new crankset. After going to the bikeshop and getting it installed, the problem was still solved! The wobbling was less but it was still quite obvious that the chain wobbled a little and then continued normally. So what could the problem be?? I am now very confused. The crankset is neither shimano nor sram, it is the maker's own part. Is it possible that all the models of crankset contain a defect meaning that the crankset wasn't designed properly? Moreover the bikeman in the bikeshop told me that it could be an installmentproblem, meaning that the crankset is not sitting right or something. Could it be it? Or what could it be?

Would appreciate it if you could help me with my question :)

Posts

  • JGTRJGTR Posts: 1,404
    I would if I could understand what you were saying, doesn't make much sense to me.
  • cooldadcooldad Posts: 32,599
    The bike is?
    The crankset is?

    Anything is possible.
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  • The RookieThe Rookie Posts: 27,811
    Vanishingly unlikely it's made by the bike manufacturer (who are?) it will be made by one of the big companies and branded.

    Make and model of bike plus known details such as BB type would be helpful.

    If the bike shop guy said it was an installation problem having just installed it, ask him to do it again.

    "The problem was still solved"? Really?
    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.
  • chrisrahi9chrisrahi9 Posts: 41
    JGTR wrote:
    I would if I could understand what you were saying, doesn't make much sense to me.

    Apparently,i did some mistakes while writing (not a native english speaker). To sum up all of this, the bike is a commencal meta ht am essential 2016 model (bikeradar has made a review on it). The model of the crankset is ride alpha which is made by commencal to keep costs down (just lile syncros is made by scott). So I just wanted to recieve a few thoughts on this. What are the causes of the chain wobbling other than that the teeth of the chainring is bent? I mean they sent a new but same model crankset and the problem was still not solved.
  • chrisrahi9chrisrahi9 Posts: 41
    The Rookie wrote:
    Vanishingly unlikely it's made by the bike manufacturer (who are?) it will be made by one of the big companies and branded.

    Make and model of bike plus known details such as BB type would be helpful.

    If the bike shop guy said it was an installation problem having just installed it, ask him to do it again.

    "The problem was still solved"? Really?

    Apparently,i did some mistakes while writing (not a native english speaker). To sum up all of this, the bike is a commencal meta ht am essential 2016 model (bikeradar has made a review on it). The model of the crankset is ride alpha which is made by commencal to keep costs down (just lile syncros is made by scott). So I just wanted to recieve a few thoughts on this. What are the causes of the chain wobbling other than that the teeth of the chainring is bent? I mean they sent a new but same model crankset and the problem was still not solved.
  • JGTRJGTR Posts: 1,404
    If it's had a new crankset then the bottom bracket or frame must be bent.
  • The RookieThe Rookie Posts: 27,811
    It won't be made by Commencal, it will be bought and branded, if you're cynical you'd guess they were using a cheapo one and branding it to hide the identity! Prowheel or similar at a guess.

    It can't be the frame doing what you describe, it could be the BB but a bent ISIS is unlikely, that said the BR review also says square taper which are known to bend, so you'll have to tell us what it is.

    Most likely it's just a bent chainring, you can straighten them using adjustable spanner, like straightening a disc.
    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.
  • chrisrahi9chrisrahi9 Posts: 41
    The Rookie wrote:
    It won't be made by Commencal, it will be bought and branded, if you're cynical you'd guess they were using a cheapo one and branding it to hide the identity! Prowheel or similar at a guess.

    It can't be the frame doing what you describe, it could be the BB but a bent ISIS is unlikely, that said the BR review also says square taper which are known to bend, so you'll have to tell us what it is.

    Most likely it's just a bent chainring, you can straighten them using adjustable spanner, like straightening a disc.
    Thanks! I try to figure it out.
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