Nick as Ian has said, you can get a speedo healer to correct the readout 
Ian, thanks for that. Although your right, there is no "kit" listed for our bikes, they do sell all the component parts individually on ar-racing. Its only about £14 for a front sprocket, and about £35 for a rear, so I could maybe buy a couple to try out different setups I suppose.
Still interested in hearing others experiences of changing the amount of teeth as well though
Ian, thanks for that. Although your right, there is no "kit" listed for our bikes, they do sell all the component parts individually on ar-racing. Its only about £14 for a front sprocket, and about £35 for a rear, so I could maybe buy a couple to try out different setups I suppose.
Still interested in hearing others experiences of changing the amount of teeth as well though