Looks like I'll have to spray-paint the spokes

It's probably the slight difference in spacing but the chain isn't running smoothly in the higher gears. Do cassettes take time to break in (it is a cheap Shimano job that looks almost chromed)?

I think I'll replace the chain with a new one whilst waiting for the new shifter, it doesn't appear to be stretched but has done 1300 miles, and as I've only just replaced chainset and cassette I think it makes sense.

Richard