9 Speed Chain Skipping on 10 speed cassette - incompatibility issue ?

andyrr
andyrr Posts: 1,822
For a good few years, since I pretty much stopped racing, I’ve been using my TT bike on my Kurt Kinetic wheel-on trainer. I ran a 9 speed Shimano transmission on it with 10 speed bar-end shifters in friction mode for all the years I raced on it and I continued in that way on the turbo.
A while ago, for some reason (cannot now remember why) swapped over to another wheel with a 10 speed cassette on it, half expecting that the 9 speed setup on the bike might not shift ok. I was pleasantly surprised to find that it functioned ok so took no further action.
Now I’ve taken delivery of a JetBlack Volt DD trainer and I found it tricky to setup the indexing with the 10 speed cassette of the turbo TT bike wheel installed and the chain sort of ‘hops’ on the smallest sprockets. I’ve just tried another of my bikes with a full 10 speed setup and it is pretty good across the cassette. I don’t want to use that bike on the turbo as it’s in regular road use so constantly swapping cassette from wheel to trainer is a bit of a PITA plus it’s a wide range 11-32 as opposed to, I think, 11-25 on the old TT bike. 9 speed chain is old but not significantly worn when checked with my Park tools chain wear tool.
So, KMC X9 chain / 10 speed cassette - is that a just the simple source of my dodgy shifting?

Comments

  • andyrr
    andyrr Posts: 1,822
    To add - I guess I could probably get closer to identifying the issue by swapping bikes and cassettes on the turbo, ie TT bike with it’s 9 speed chain with the wider range cassette of my road bike and then try the road bike, with it’s 10 speed chain and the closer range cassette off the TT bike.
    There are wear differences in cassettes and chains to complicate matters though - the road bike with full 10 speed transmission has matching new cassette and chain.
  • webboo
    webboo Posts: 6,087
    Would it not be best just to put a 10 speed chain on.
  • whyamihere
    whyamihere Posts: 7,713
    I would put a new 10 speed chain on. Your problem might be due to the wider chain, it might be worn, but the other point is that Shimano 9 and 10 speed (other than some weird Tiagra stuff) uses the same pull ratio, so you could run the shifters in indexed mode and just have a full 10 speed setup.
  • andyrr
    andyrr Posts: 1,822
    Thanks - yup, I’ve now bought a pairing of 10 speed chain and cassette - from CRC as they had SRAM PC1031 chains for £9.99 plus a new cassette since the existing one has unknown mileage and chucking the nice new chain on might still result in some skipping or whatever. And, as you say, it means the indexing will work as it’s supposed to.