Turbo trainer spare wheel crunching noise

[Mwoodhouse]

Recently got myself a turbo trainer and used an old wheel threw a new cassette on it to speed up setting it up. The problem I'm having is that the new cassette is making an almighty clunky crunching noise when I pedal (needless to say I've not beed doing much of that). Then it's absolutely fine when I'm back on the old cassette on the outdoor wheels. For reference the indoor wheel is a mavic cpx22 rim with shimano hub, outdoor wheel is fulcrum racing 5 with shimano hub and cassette is a shimano hg50 8 speed. I'm wondering if there's any slight differences between the two wheels that might be affecting the alignment of the cassette and causing the racket. Any help would be greatly appreciated.

 

[BimblingBee]

More likely that the old chain and cassette have worn together and the new cassette and old chain combo don't like eachother.

How worn is your chain? Have you measured it?

 

[Mwoodhouse]

12 links are 12 1/4 inches. New chain and cassette?

 

[BimblingBee]

Yep, or run it into the ground if its still shifting ok. Check chainrings too...

 

[Mwoodhouse]

Tempted just to change anyways to get it running smooth on both trainer and road, gives me a good excuse for a bike fiddling day too. What sort of things would I need to look for on the chainrings?

 

[BimblingBee]

Let Sheldon explain! (Scroll down a bit...)

http://sheldonbrown.com/chains.html

 

[accountantpete]

I presume you are running an 8spd cassette on both wheels.

No two wheels will be exactly the same. The freehub on the old wheel may be a little further in or out than the other one and you may need to turn the rear mech adjuster slightly to compensate.