Possibly dumb question

germcevoy

My bike is 11 speed 105 with around 2000 miles on the drivetrain. I need another cassette for a turbo wheel.I can buy a new cassette for the bike and transfer the existing cassette to the turbo wheel but I'd then need to replace the chain as well which doesn't seem a brilliant idea just before winter.

I'd rather keep the existing chain and cassette through winter and replace the lot early next year when the worst of it is over. Similarly I don't want to buy a brand new cassette for turbo duties and cheap used 11 speed cassettes are hard to come by.

Theoretically, would a 10 speed cassette work for turbo duties?

keezx

You can use 10 speed cassettes in a 11 speed setup, but shifting will be erratic.
Likely no problem if you use only 2 or 3 cogs.

mfin

You would not need to change your chain if you change cassette in your situation after 2000 miles.

Also 11 speed 105 cassettes are only about £28 new.

You're getting your chain change logic mixed up. Let's say a bike is new, when the chain wears out, you fit another, that runs out you do it again. You tend to find you can get 3 chains per cassette change. So, one day you replace your worn chain and find your shifting has gone crap or the chain just jumps a bit in some sprockets under power, that's when you know you need a cassette as well. (Chainrings can last longer than cassettes too).

Or... perhaps you already know all this and your chain change is down the the fact you will be using a lot bigger cassette and need the chain to be longer?

germcevoy

mfin wrote:

You would not need to change your chain if you change cassette in your situation after 2000 miles.

Also 11 speed 105 cassettes are only about £28 new.

You're getting your chain change logic mixed up. Let's say a bike is new, when the chain wears out, you fit another, that runs out you do it again. You tend to find you can get 3 chains per cassette change. So, one day you replace your worn chain and find your shifting has gone crap or the chain just jumps a bit in some sprockets under power, that's when you know you need a cassette as well. (Chainrings can last longer than cassettes too).

Or... perhaps you already know all this and your chain change is down the the fact you will be using a lot bigger cassette and need the chain to be longer?

I had always operated on the mantra of changing chain and cassette together which is why I alluded to not just buying another cassette in case it didn't mesh well with a used chain. If I can get away without a new chain before winter then I'll stick with the current cassette for the road and get a new one for the turbo.

Current cassette is 11-28. I was flirting with going up to a 32 as I'm on a semi-compact up front which I haven't quite made my mind up about yet. The FSA rings are like butter so a decision to make about ratios but I'll likely wait until the other side of winter.

mfin

Well, I don't know where you got the mantra of changing chain and cassette together, you're wasting money. If you change the chain as soon as a £5 chain checker tells you to then you can get 3 chains out of one cassette no problem at all.

If you go to a 32 from a 28 you might need an extra link but it is not possible to say without seeing how much play you've got. Also bear in mind some rear mechs won't play ball with 32, but if you are running shimano I don't know about the particular caveats with each shimano mech.

meesterbond

My lbs (or the one I usually trust with anything vaguely tricky) work on the basis that you should always change your chain when you change your cassette but you don't need to work the other way round.

An ideal state would be to have a couple or three chains on rotation so that the wear on the cassette is spread out a bit but frankly does anyone have the time or inclination! Just keep an eye on chain stretch and when it gets to .75% get a new one.

balthazar

Worn chains wear out good sprockets quickly, but worn sprockets don't wear out new chains.

That's because as chains wear, their pitch changes (distance between links), with the effect that the full pedalling load is borne on only one or two sprocket teeth, rather than divided among all the teeth in contact. When sprockets wear out, their pitch doesn't change. Eventually they sharpen to points and the tooth bed is such a shallow ramp that the driven chain can ride up on the teeth and skip a tooth ahead (no fun!)

Hence the good advice above: ditch cheap worn chains that are destroying expensive cassettes, but run cassettes until they slip (or it's getting near). I'd never pair a new cassette with anything other than a new chain, but equally- your old cassette will be fine with the new chain too.

fenix

Your whole logic my be wrong. Try your tyre on the turbo first. You may not need. Whole new wheel. At the worst you may go through the tyre quicker than on the road but that's still going to be cheaper than the wheel.

germcevoy

Fenix wrote:

Your whole logic my be wrong. Try your tyre on the turbo first. You may not need. Whole new wheel. At the worst you may go through the tyre quicker than on the road but that's still going to be cheaper than the wheel.

I already have a spare wheel so it makes sense to have a turbo tyre on that wheel so I can save my good tyres that are on my good wheels.

The turbo has already made light work of my usual winter tyre, a Michelin Lithion 2. I wouldn't let my GP4000sii near the turbo.