Suntour XC Pro shifters are designed to work with the Suntour XC Pro cassette, which didn't have consistent spacing between the sprockets (whereas a Shimano one does), so the indexing won't work properly. IIRC the smallest three sprockets were one distance apart from each other, the next two were another and the biggest two another still. But that's from memory - my early 90s copy of Sutherlands is elsewhere at the moment.
In short, Suntour shifters are IMO the nicest thumbies ever made, but they only work properly with Suntour cassettes!
: P
In short, Suntour shifters are IMO the nicest thumbies ever made, but they only work properly with Suntour cassettes!
: P