Am having trouble sorting out a mates bike.

Not sure if it’s possible to avoid the chain catching the mech as it’s a tad wider?

The chain will clear granny and 1st and big ring and 8th but when I try middle and 1st or 8th it’ll only clear on 8th gear. If I reduce cable tension to clear 1st gear it throws out clearance in big ring and 8th.

I tried setting the mech with 3mm clearance from top of big chainring to start with and have had to move it higher up the seat tube a few times at the moment the clearance is around 8mm.

Think I remember reading that you need to set the mech higher but not too sure.

TIA

Andy

Anyone>

I have this setup on 3 bikes, all work fine. Well, I never use the extremes on the middle ring – I didn’t think they were valid combinations for the reasons you specify.

Oh right it can be done then!
I thought in middle ring you should be able use all the gears?
Did you have to set the mech high as well?

Cheers

It can be done, but you will either catch the chain on the largest or smallest sprocket.
9-speed mech has a narrower cage than an 8-speed.
11/128″ versus 12/128″ chains.

Want the solution?

Use a 9-speed chain.

KMC guarantee it will work, and I have this working on a couple of 8-speed set-ups to verify the claim.

PaulD

Cheers Paul I’ll suggest that to him, which KMC chain and where’s the cheapest place for them?

i’m using 10 speed road mechs on a 8spd road drivetrain all works fine,
i’m really good at keeping a good chainline though which probably helps

9 speed will be fine

Cheers for that colande.

Would a sram 9 speed chain work as well as a KMC, think I’ve got a spare one he could try.

Mine works fine but you need a 9 speed shifter as with the 8 speed it used to rub.

you’re only talking 0.15mm width difference at either extreme between 8 and 9 speed chains.
been using 8 speed chains with 9 speed front mechs for years and years with zero rub at the mech cage.

zippykona – cranks’ chainring tab spacing hasn’t changed (ie. any decent front shifter will be fine).

Since KMC guarantee their 9-speed chains to work with an 8-speed drive train, I have used other makes (YBN hollowpin from XC Racer and a SRAM PC991) successfully on 8-speed XTR cassettes with M960 rear mechs and a mix of 8 and 9-speed front mechs and 9-speed Shimano shifters.

All OK.

PaulD

8 speed chains are almost half the price of 9

Thanks again.

I cant get it to run clear of 1st and 8th in middle ring with the 8speed chain so I’ll try it with the 9 speed chain, the only doubt is how worn his drive chain is and if a new chain (8 or 9 speeed) will run ok.
If that doesn’t work then he can take it to the LBS or we’ll try an 8 speed front mech!!

Thanks for help