kcham16

hey- i am having a hard time finding 10 speed chainrings anywhere, without buying new cranks. the guy at my LBS told me i could file my 8-9 speed chainrings down a little on each tooth, and that they would work fine. has anyone ever done this, or do i need to buy new rings? thanks!

miyata610

You don't need to... those chainrings will work fine with a 10s chain etc etc etc.

p.s. I have used chainrings that were designed in the days of 5 speed clusters with an Ultegra 10 speed chain, cassette and dreailleurs... they work just fine.

cs1

It's not so much the chainrings but the spacing between the chainrings. The theory is to reduce the spacing on 10 speed chainrings to reduce any chance of the narrow 10 speed chain getting stuck between the chainrings. In practice it really doesn't make much of a difference. Good luck

Tim

Michel Gagnon

cs1 is right in theory. In practice, it hardly matters. I'd suggest you keep your chainrings (you already have the 8 or 9-speed crankset, right?) and use them as is. If you realise that the chain likes to float in the space between rings, then file the spacers.

P.S. I'm not at 10 yet, but I have one bike with 8-speed chainrings and another one with 7-speed chainrings. Yet both work with a 9-speed cassette, shifters and chain. No problems.

cs1

Michel

Problem Solvers actually makes different size spacers. They are popular with Campy 10 speed users. You take off the big chainring and insert 4mm spacers and Viola 8/9 speed spacing on a 10 speed crank.

Tim

LittleGinseng 

That's .4mm. And there's one thing the OP needs to know. The reason the LBS suggested to file down the teeth of an 8-speed chainring is so you don't experience possible chain suck. A narrow 10-speed chain stands the chance of not shifting completely when moving from the large ring to the small ring. This could result in your crank locking up, bending a chainring and/or chain, damaging the right chainstay(especially if carbon fiber),etc. Do yourself a favor: purchase the correct chainring.

rmac

Wow. I've never had this problem with a 10sp chain on an 8sp crank. I always thought that the inside width was the same and they just changed the outside width.

moxfyre

+1 ... derailers and chainrings will work just fine with a different number of cogs than they were originally meant for. Although a 10-speed chain's OUTER WIDTH is much narrower than, say, a 6-speed chain, the INNER WIDTH of derailer chains has not changed in decades (it's 3/32"). The only thing that really needs changing when you add more cogs is the cassette (obviously ) and the shifters.

Shimano likes to very slightly tweak the width of derailer cages and chainring spacing when they move up to a new number of cogs... then they encourage everybody to unnecessarily replace these parts to make more money Also, with 10-speed drivetrains Shimano has switched triple cranks and front derailers from 52-42-30 to 53-39-30. This means that if you use a "10-speed" triple crank you'll want to have a matching front derailer.

CrossChain

6spd Uniglide cassette and matching crank/rings work fine with 9spd chain for me.