Originally Posted by
ksryder
FWIW these work indexed for 7 & 8 speed (I've actually done it, not just speculating). When you use them with a 7 speed the extra click just disappears. I'm not mechanically smart enough to figure out where the extra click goes, but it just works. Of course if you use them in friction mode it works with any speed you want. Had them set up 10 speed for a while
There's a lot of threads on this and there is some disagreement as to whether you can dial this in well enough for some people to be happy with this set up. Some people like you are very happy with this set up; others not so much.
St. Sheldon has a good crib sheet on this,
https://www.sheldonbrown.com/cribsheet-spacing.html
There is a difference of .2 mm in spacing between shimano 7s and 8s