Join Date: Dec 2013
Location: Sydney Australia
Looks like your front sprocket is wearing normally - that is the U is starting to widen and wearing one side of the tooth more and creating a hook - just normal type of wear for old sprocket.
Now the splines are worrying. you can see that the splines have a different shape 1/4 the way in. the splines should all look the same for the full depth of the spline, yours looks like it is also wearing like sprocket. I have not seen this before.
If you are not the original owner then previous owner may have put on a cheap sprocket that was loose. Sprockets should be nice exact fitting (not tight), definitely not loose. By loose I mean that the sprocket can rotate on the splines if rotated. If the sprocket was loose then the movement and shock of launching the bike, hard launches and clutch slamming might have cause the wear you see on the splines.
Last edited by Gigitt; 02-17-2017 at 02:35 AM.