by waaytoomuchintothis » Mon Jan 14, 2013 1:20 pm
It should be mentioned that the reason for this technique is that the knurling is slightly larger than the rest of the axle on knurled axles, chiefly Carrera and Scalextric, but there are others. In order for the factory workers to slide bushings on the axle, the bushing's hole is slightly larger to accommodate the knurling. Then the plastic wheel is installed. Pull and axle set out and wiggle the bushing to see the slop. The slight amount of slop this creates can be bothersome sometimes, and that is why some cars with knurled axles don't handle well. I never have figured out how Carrera usually avoids the handling problem, but even the most smooth of these cars can be improved by this technique.