10spd chainset on a 9spd groupset

Shure

Would anyone be able to clarify if I would be ok to run a 10spd chainset(Shimano Deore M622) on a full 9spd groupset inc chain?
I'm looking to repair an old bike as economically as possible which needs a new chainset inc BB.
There seems to be far more deals on Shimano 10spd triples rather than trying to find the 9's.

steve_sordy

10-speed will run fine as long as you change the shifter.

Try it first, you may have to change the mech, but I doubt it.

Shure

Forgive my lack of knowledge on this but why would the shifter need changing if it's still a 3x?

steve_sordy

I have read your OP again and it is unclear to me whether you would be keeping the 9-speed chain (ie "inc chain"). A 9-speed chain will not run on a 10-speed cassette because the chain is too wide to run between the gears as they are too close together. The 10 gears are closer together as they have to fit into the same width as the previous nine. The thinner 10-speed chain will however run on the 3-speed front rings despite it being narrower, because the gap between the sideplates is still wider than the gear teeth.

The shifter you need to worry about is not the front one that remains 3-speed, but the shifter for the rear. The 9-speed shifter moves the chain 8 times to move the chain from gear 1 to gear 9. It will not move the rear mech 9 times to move the gear from gear 1 to gear 10.
You cannot even give up one of the ten speeds by setting the limit stops appropriately because the gap between the gears on the 10-speed cassette gears is still less than that between the 9-speed cassette gears. Shifting will happen of course, but under pressure you won't be happy with it in the middle gears!

However, the rear mech is a slave to the shifter because it has no indexing mechanism of its own. That is why I said to try it first. I don't know enough about all the possible designs of rear mech to be able to say with confidence that a 10-speed chain will definitely run through a mech that was originally designed for a 9-speed. This is why Shimano make different rear mechs for 9 & 10-speed set ups. But I believe that it probably will without much, if any, problem.

dgunthor

Shure wrote:

Would anyone be able to clarify if I would be ok to run a 10spd chainset(Shimano Deore M622) on a full 9spd groupset inc chain?
I'm looking to repair an old bike as economically as possible which needs a new chainset inc BB.
There seems to be far more deals on Shimano 10spd triples rather than trying to find the 9's.

yes 10spd chainset fine with the rest of the 9spd group

JBA

If all you are changing is the chain set then it will be fine.

larkim

Steve - https://en.wikipedia.org/wiki/Crankset - he's not changing the rear at all, just the chainset (UK term) which is the crank / chainrings at the front.

swod1

should work fine I'm using an slx m7000 chainset which is technically 11speed with 10speed chain/cassette and no issues at all.

Shure

Thanks all, would any amendments to the chain be required at all or is it a like for like replacement?
I'd be going from a 44/32/22 to a 40/30/22.
Apologies if these seem like basic questions...

keef66

No, stick with 9 spd chain if all you're changing is the chainset

steve_sordy

Shure wrote:

Thanks all, would any amendments to the chain be required at all or is it a like for like replacement?
I'd be going from a 44/32/22 to a 40/30/22.
Apologies if these seem like basic questions...

You might need to shorten the chain a bit.

Shure

Thanks for the advice all, got the new crank fitted today and on the whole it's fine.
There is some rubbing of the chain on the ront derailleur at the extremeities of the gears, not sure if thats just an adjustment thats needed or an effect of the difference in chain width of 9 vs 10 speed.