i kept having problems with the chain on my bike with it being bounced off. I took a link out in order to tension it, and moved the wheel further forward. however.....there is a "keyed" nut (ie it has a knob that slots into the axle slots) that seems to perform the function of stopping the axle spinning (there is a flat spot on the axle sides). is this its purpose. is it ok that instead of the noble facing rearwards it nows faces forward. many thanks panda -- change "net" to "uk"