wookv

Hi,
I just bought a cheap rear wheel and nashbar brand cassette to use with my trainer. The wheel and cassette are supposed to work with the rest of my shimano components.
However, the chain keeps skipping for the smaller gears, I can only use about 3 gears without skipping. Could it be because I'm using a brand new cassette and my 2 year old chain has been "used to" my old cassette? Or because the gear ratio is slightly different than my old cassette?

Can anyone help me troubleshoot. Thanks.

1nterceptor

Try new chain. Should be ok.

caloso

Most likely.

banerjek

As others have stated, it is extremely likely that you need a new chain -- components tend to wear together.

I strongly recommend fixing this sooner rather than later. If you run an old chain on a new cassette too long, you'll prematurely wear the cassette so it will start skipping when you buy a new chain.

wookv

thanks! I'll try to get the chain changed soon

stockae92

First, check the cogs and make sure they are installed in the correct orientation.

There are rams that aid shifting. If they are installed backward, the chain won't stop skipping (i.e. trying to shift into the next gear)

just take the cassette out, check while reinstalling it.

JohnJ80

Chain first and if not that, then it's a worn chain ring.

J.

draganm

if the chain is slipping, jumping up and off a cog under load and then coming back down on the same cog, it's definitely chain or cassette wear. Get yourself a chain checking tool, they're cheap and if you catch it early you will prevent a worn chain from prematurely wearing out a cassette.

at 8:47

Homebrew01

Your rear derailleur most likely needs to be adjusted for the new wheel, specifically the cassette's position on the hub.
What have you done so far ?
A turn or 2 of the barrel adjuster is usually all that's needed.

If it's skipping to the smaller gear, then unscrewing the adjuster (counter-clockwise) will use up cable and pull the deraileur inboard towards the larger cogs. This is referred (inaccurately) as increasing cable tension. What it really does is make the housing longer, thus pulling the cable, which pulls the derailleur inboard

Clock-wise, screwing it in, shortens the housing, allowing the derailleur to move outboard.

I usually turn about 1/2 turn at a time between testing.

Homebrew01

Moved from "Road"

IrishBrewer

I totally agree with this. I have a trainer wheel with the exact same cassette as my road wheel and I have to make minor adjustments when I swap them. All it takes is a very minor difference in the position of the cassette on the wheel for it to need a minor barrel adjustment. Look at the drivetrain from the wheel in line with the chain and see how the chain is positioned between the cogs and adjust the barrel to get the chain perfectly centered between cogs. You can check multiple gears but generally it is best to make the final adjustment halfway through the gears.