'Spacely Space Sprockets'

[secaIIwarrior]

Got a question for anyone with the info, how do I find out what other bikes front sprockets will interchange with the xj600??? It's part of my Warrior project, I can't use the rear sprocket from the bike, and the current rear is substantialy smaller, and the bikes front sprocket is several teeth larger. So I want to keep a ratio for more bottom end power not so much top end, and this current setup makes it twice as far in the wrong direction. I know my current is a 16 tooth, but want to drop to a 12 or 13. The spline is the issue, I can deal with spacing. Thanks! rich