I (we) are using a rear shock from a Yamaha YZF 600 (I think). Mr. Bigwheel was kind enough to provide me with a shock from one of his previous attempts at rear shock upgrade. The measurement from the centerline of the rear axle to the rear fender (measured from the axle to where the end of the seat meets the fender) is 23.5". I am not sure what the stock measurement is, but a couple of inches of travel is gained, plus I now have rear dampning where the stock (25+ year old) shock seemed to provide no rebound damping whatsoever. I ran this setup on the rear for most of the summer without an upgrade to the front suspension. With the rear suspension jacked up and the front not modified the steering angle was rather steep and caused some rather twitchy steering. I now have a tri-z front suspension on the BW and now have a steering angle which is much more relaxed and easier to handle (in addition to a front disk brake!). The only disadvantage from what I can tell is that the primary chain has to be run a bit looser than what many may be comfortable with in order to cope with the geometry of the longer suspension travel.