Three bike dealers near me all differ on this question. I asked whether I could just buy from Santana one of their 11 to 34 rear cassettes, which they put on this webpage
on 2 November '05 and put it on a newish Co-Motion with 145mm rear which currently has a 9 speed Shimano cassette and triple in front. One dealer says it won't work, 2nd says it will but won't work well; 3rd says it will work fine with the right chain. Obviously I turn to the experts here for the final word!