Chain slipping/jumping

garetjax Posts: 175
edited January 2012 in Workshop
I was out today and when I pedaled hard going up a hill my chain was slipping and making a horrible noise. The chain kept coming off and I had to cut the ride short and head for home.
Strangely, the bike was fine on the flat even though I was quite cycling hard, although I was mostly in the big ring.
Last week i went out and did the same hilly route and it was ok.

Ive booked it in for a service, but what could be the cause? I have never changed the cogs or chain. Ive sent off for a chain stretch tool to see if that's the cause, but would you expect a sdden change from one ride to the next?



  • mrwibble
    mrwibble Posts: 980
    is it a new chain on an old cassette for vice versa? is your chain well maintained?
  • Wirral_paul
    Wirral_paul Posts: 2,476
    How old is chain / cassette (in miles)?? I think i'd be pricing up both a new chain and cassette while waiting for the tool to arrive to be honest. Hopefully its just a chain needed.

    I assume you checked the indexing and cleaned / lubed the chain after getting home, just in case??
  • just had this on mine, changed the rear cassette and chain first and now buying a new centre ring for the front as it seems only that is worn. I can use small and large rings across all rear sprockets but even when I'm centre centre front and rear it jumps on the front middle sprocket!