LBS sold me a 9 speed chain and I have a 10 speed

They are closed and I wanted to ride so I cut the chain down till it matched my old chain in number of links.

What other differences are there between the two?

10 is slightly narrower to fit between the cogs that are spaced closer together.
How well did it work ?

Not to good, skips a lot and seems to be trying to get in the next ring up when in 2,3,4

You may be able to get it to work by adjusting the cable tension on the rear shifter. Turn the adjuster in (clockwise as you look down at it) 1/4 turn, and see if that resolves it. If not try another 1/4 turn. Repeat until it gets better, or worse. Keep track of the number of 1/4 turns, so you can go back if reducing the tension doesn't fix it.

Was the old chain badly worn? If so, and the cassette is now worn, you will have skipping issues anyway.

Now I see 6.5 mm wide on the 9 and 5.8mm wide on the old 10.

4965 miles, maybe I should get a new cassette and the right chain??

There's a difference between "load" skip of a new chain on a worn sprocket, where the chain skips under load, and "trim" or "shift" skip where the chain is trying to move to an adjacent sprocket. If the OP has a problem with auto-shifting, The wider chain isn't helping. He might be able to solve it by adjusting the trim outboard a bit.

OTOH- the OP says the dealer sold him a 9s chain for his 10s bike. Did he not read the box, or did the dealer assure him it would work?

Just an honest mistake on the wrong chain, and me not checking the width when I knew it may not work.

So, what about that new cassette with the right chain? Is the cassette easy to change or should I leave that up to the LBS

btw, only .009 clearance between the chain and the next cog, that's about the width of 2 to 3 sheets of paper

old chain is .027 narrower than the new so I've lost 2/3 of my clearance with this wrong chain.

Cassettes are easy enough to change. All you need is a cassette lockring tool, and a chain whip or other means to keep the freehub from spinning as you loosen the lockring.

OTOH, cassettes aren't cheap, and if you're getting skip or auto shift because the chain is too wide, the cassette may be fine. In your shoes, I'd get a new chain first, and see how it runs, then decide about the cassette.

I measured my cassette and do have .015 to .020 wear on the 2,3,4 cogs as compared to the others. Starting to think this is more of a wrong chain problem..

If lbs can put a new cassette on my wheel while I wait then I'll do that plus the right chain. If not, then I'll just do the chain

Thanks for all the help guys

Whatever you decide. However you might save the old cassette, which will probably run fine with a somewhat worn chain.

If the cassette's of any quality, it should last past 5k miles. However, if you've never swapped out the chain, any chain will of course skip. If you're gonna put on a new cassette, do you plan on swapping out everything else while at it, too? I mean all the other parts have 5k on them too, right?

Quite right, but since he mentioned both "skipping" and the shifting issue, it ocurred to me that we may be dealing with two different problems. Finding out whether the old chain was badly worn would help determine whether we had two problems, or just one.

I'd say (as others have) start with the right chain, but don't run it too long before deciding whether the skipping problem is cassette wear. If there is excessive cassette wear, you'll shorten the life of that new chain considerably running it on a badly worn cassette.

I didn't really have any problems before changing the chain.

Recently replaced wife's 8 sp chain with a what I thought ( the battery's dead on my caliapers ) was a 9 sp chain . Turned out to be from a 7 sp drive train . It did what yours did , put back on a used but good 8 sp chain & works fine
( I'm still waiting for my 2/ 10 sp wuppermans)

its the chain


cheers

Got the right 10 speed chain on there today and fixed her right up.

Thanks for all the help

7sp and 8 sp chains are the same

the problem was probably one of adjustment or wear
but not of compatibility

My bikes take 7 speed and one 8 speed. The chains run about $10. My wife has a 9 speed but hasn't put enough miles to need a new chain. My son has a 10 speed and we went to the Lbs for a new chain and I almost fainted at the prices. A Sram 9 speed was $25 and a Sram 10 Speed was $44!

I am soooo glad my chains don't cost so much.

I bought my last chain online for $27, a nice kmc chain. 10 speed. I'll get about a year's worth of riding out of it.

Thanks , thought 5,6,7 were same & 8,9,10,11 were all different , I looked & your correct . Now seems odd that my old pull off box of chains ( from freewheel days) won't work on wife's 8 sp . Gotta get battery for calipers .

Cheers

i think 5 and some 6 speeds were not compatible
with modern 7/8 speed chains

my understanding is
suntour narrowed the spacing for their ultra 6
and shimano redesigned the chain for 7 speed
and called it hyperglide

my wife had a beautiful fuji 3x5 mtb
which eventually got stole
and i couldnt figure out
why the 7 sp chain i put on it
kept skating between the cogs

It's tuesday , did you buy the right chain by now?


older chains had the rivet head proud, above the side plate,
those are only sold as single speed/IGH chains now.

new derailleur chains have the pins nearly Flush with the surface of the outer side plates of them ..