Originally Posted by
embankmentlb
I would look for a Sunrace cassette.
...either this, or I have at times used an 8 cog cassette from Shimano, leaving off the smallest cog.
With the 8 cogger, you're changing the spacing a little bit, I think. But in my applications, it didn't seem to matter.
If you've got 7 speed indexing, you can either run it in friction, or dial out the 8th position with the limit screw, and adjust the indexing to work best in the middle range. This is usually all you need for it to work OK.