Once you move the rr rearward it changes toe... roll the kart still toe is off... take the steering lock pin out and roll the kart toe is good, but the steering wheel moves to correct the toe so if you made no changes to the front why did the steering wheel change location? If you move the steering wheel that would be steering correct?The rear isnt steering, put your toe lock in, move the rear axle back then roll the kart and see what happens, youre thinking about what happens statically, and not what happens when the kart is moving, once youre rolling the wheelbase is back to what it was originally but what the hell do I know, weve only been karting for 20 years and full scale 15 yrs before that, and I worked for and sponsored by a major kart chassis company for 9 years, so have at it.