Pedals slipping forward

Bobblehatboy1975
Bobblehatboy1975 Posts: 36
edited July 2017 in Workshop
My sons road bikes pedals are slipping forward somtimes, it doesn't a make a noise. It's happens sometimes when he changes down chainrings and happened last night when he was in small chain ring and small sprocket at the back. He has 2 sets of wheels and it's happening with both of them.

Comments

  • andy9964
    andy9964 Posts: 930
    Time for a new chain?
  • Andy9964 wrote:
    Time for a new chain?

    I can try that, I though that a chain slipping would make a grating sound?
  • sungod
    sungod Posts: 17,413
    ...in small chain ring and small sprocket at the back

    that's not a good combination, depending on overall set up it may be the cause of the problem as the chain will be at lowest tension

    in general: when on the big chain ring avoid the biggest 2 sprockets, when on the small chain ring avoid the 2-3 smallest sprockets

    you can easily check the chain with a ruler...
    https://www.sheldonbrown.com/chain-wear.html
    ...scroll down to "Measuring Chain Wear"
    my bike - faster than god's and twice as shiny
  • Thanks Sungod,

    Yes, I know it a bad combo, however my son is only 9 and gets the gears wrong sometimes, still it shouldn't be slipping.

    Thanks for the link.