help with a knock/slipping in smallest cassette cog
 

Last night I decided to swap wheelsets between my 2 bikes- one with 8speed Sora and the other with 10speed Rival. So I pulled the cassettes off and carefully reinstalled them on the other wheel- the 10spd cassette is now on Mavic Aksiums, with a spacer put on before the cassette.

When I put it on the bike and turn the pedals, all seems fine until the bottom(smallest) cog which skips horrendously, roughly twice per crank revolution. The r/d appears to be aligned all the way up and down the cassette so I'm unsure about what the problem is- does anyone have any suggestions?

Thanks.

The rear der. needs to be a little outside of the smallest cog. If it sits directly under the cog you can have shifting problems. Use the high limit screw to set it.

The rear derailer just need to be readjusted to fit the new wheel, including limits and cable.

Is the smallest cog an 11? If so it needs to have the special lockring for an 11. An 11 with a standard lockring will cause the chain to skip.

Al

Also check whether the spacer is needed. Some 10-speed cassettes need a spacer to fit on some 8/9-speed wheels. Some don't. If you have too many spacers on there, the top cog may not engage enough of the freehub splines and could slip.

Thanks for all replies- I think I've almost got it.