Hello... quick one.. I've been cleaning my chain & sprocket today and noticed that the chain appears to be very tight. Can you help me with my calculation... I've worked on the basis that I measure from the swingarm to the chain (25mm) and then push the chain up and take measurement again (15mm) and then minus one from the other leaving me with 10mm.. The book states the travel should be between 21-30mm. In addition I've discovered that I have a non-standard rear sprocket with 45 teeth instead of 43 - would this make any difference to the chain tension? Thanks Mark