Home Chat General Chat

Crank slipping when putting power down

Hi

Did abit of research and i am yet to find an answer to my problem......

When i try and go fast on the bike and move up gears and put the power down the crank seems to be slipping under the chain.... its rather difficult for me to explain as i dont really know what is going on myself but if anyone has heard of something like this happening, can you let me know what you did to fix it?

Thanks
JB

Comments

  • shadowone1shadowone1 Posts: 1,408
    Can you video it and upload it onto you tube?

    Then post the link from youtube to here and then we can see what the prob is
  • largeadelargeade Posts: 166
    I'd love to see a video of him going fast, moving up gears and simultaneously videoing. That has You've been framed all over it

    I'm no expert, but I guess the first questions are

    a) is it the chain slipping on the front chainring or in fact is it slipping on the cassette.
    b) are you changing up the the front or rear gears at the time of the slippage.

    If you're changing up on the front it could be the front deraillieur needs adjusting, the rear might point to the chain being changed but not the cassette (or time to change the chain and cassette)
  • BmanBman Posts: 442
    Could it be a worn tooth on the chainring or perhaps a stretched chain,meaning its not slotting in properly? I had something similar once, turned out to be chipped tooth on the middle chain ring in the front. Only really slipped when I put some oomph into it, but was bloody annoying. Had to swap out the chainring, chain and cassette, so they all matched up nicely. It was fine after that, but if everything is new and its just a tooth, swapping that ring should do it. I think..
  • shadowone1shadowone1 Posts: 1,408
    by largeade » 25 May 2010 11:32

    I'd love to see a video of him going fast, moving up gears and simultaneously videoing. That has You've been framed all over it
    There is piece of equipment that I like to call a turbo.....

    Then randomly someone films it.
  • largeadelargeade Posts: 166
    by shadowone1 » 25 May 2010 12:54

    [quote:2h5w1nd4]by largeade » 25 May 2010 11:32

    I'd love to see a video of him going fast, moving up gears and simultaneously videoing. That has You've been framed all over it
    There is piece of equipment that I like to call a turbo.....

    Then randomly someone films it.[/quote:2h5w1nd4]

    Sorry - wasnt having a pop, just made me smile when I thought about it.
  • jamewahjamewah Posts: 113
    My mate had the same problem on his mountain bike, his bike was so old the cost to replace the rear cassette wrote it off so he bought a new bike.

    Maybe the same problem , as he would pedal the it felt as if the chain had come off but it hadn't, the rear cassette would spin without turning the wheel.
  • graham33graham33 Posts: 265
    My mate had this problem, Like people have mentions the teeth are worn, or the chain is worn. it will get expensive to start replacing the crank, chain and cassette.......
  • shadowone1shadowone1 Posts: 1,408
    I
    Sorry - wasnt having a pop, just made me smile when I thought about it.
    I know you weren't, I felt it easier to post something on youtube rather than trying to describe it would be easier.
  • stevsterstevster Posts: 73
    Firstly check the chain for stretching, you can get a cheap tool to measure it or go to your LBS.
    If the chain is stretched check the teeth on the chainset also the cassette, hopefully if anything is worn then its just the cassette so get it and chain replaced.
    If the chainset has worn then its gonna cost a bit more Im afraid.
  • DavidJackDavidJack Posts: 2
    Hi There
    Chain stretch, chain ring and cassette wear will not make the crank arms slip. Not engage gears properly and chain slippage for sure, but not crank slippage.
    Depending on the type of bottom bracket and cranks you have it is more likely this combination than those other suggestions.
    The most logical suggestion is that your cranks have become loose at some point and have worn the spline that holds them. You've probably had your bike serviced and they've tightened everything up again, but when you pedal over the dead spot at the top and your power kicks in, thats when you'll get slippage. Not much i'm guessing but enough to annoy you.

    I'd suggest getting this checked out first.

    If its not this then, unless you're using really old wheels what we use to call a screw on "block" (usually 6 or 7 sprockets mounted in on a free hub and screwed in one peice to the hub), then the last possible idea is that the pawls within the hub have seized or are worn, which means the cassette and free hub body are slowly disintegrating the hub spline. This is almost un-heard of so i'd go with my first suggestion.

    what sort of cranks are you using by the way?

    Oh, and a video is going to be very difficult to show this movement.

    cheers

    David
Sign In or Register to comment.