birdsandlime

I just changed the cassette on my Surly Long haul trucker. Its a 9 speed cassette and 9 speed chain. My mechanic said that the smallest three gears were worn on the old cassette, so i swapped it out. After the mechanic worked on it and checked out my hubs, my bike has been making a knocking or shifting type movement that you cannot hear but that I can feel in my feet on the smallest three gears. It almost feels as if the chains going to skip, but its never skipped yet and there is no grinding sound as if its between gears. On the rest of the gears everything runs smoothly and there are no problems. Both the cassette and the chain are srams. Does anyone know what could be causing the weird feeling on the smallest three?

I originally thought it was my pulleys, and after inspecting it, one of the pulleys was gunked up and not rotating well. Cleaning and regreasing the part, though, has done nothing to change the problem.

Daytrip

Do you have a removable chain link like a Wippermann? If a Wippermann is installed backwards, it can cause problems with your lower gears.

waldowales

How much wear on the chain? Sounds like the upper cogs may be worn to match a worn chain, while the new ones don't match.

Al1943

My thought too. Have you checked the chain for stretch?

birdsandlime

The cassette was brand new when this started happening and I had the chain checked -- it was only used slightly with the old cassette and still has very little stretch and wear, according to my local mechanic.

I do have a removable link though, so I'll check that to make sure I installed it right.

Al1943

It would be wise to measure it yourself. A foot of chain should be no more than 12 1/16".