Tony, when you say to use the xl 350 frame, put a 250 swingarm into it, do you mean cr swingarm or xl 250 s/arm, Mark hi, l do listen and l take it on board, as l listen to tony, and every body else, then l work out what l can find to build up , but if it gets to hard for me , l change my mind, and try something else. We all bounce off each other experiences and expertise. Tony which model bultaco are you enjoying , is it a 360 cheers david#46