I tried searching, but nothing came up. I'm trying to remove the front and rear sprocket on a vtr250. The rear sprocket, connected to the wheel, is held on by allen key bolts. I tried removing these bolts, but they are on so tight that I ended up twisting the allen key out of shape -> now I need a new allen key And the bolts are no less tight Any ideas? The other issue is of course the front sprocket. It's got a centre bolt through the gearbox counter-shaft. When I try to turn the bolt loose it just turns the engine over, yes it's in gear. Do I jam something in between the sprocket teeth to stop it turning? Should I use WD40 or something? Was hoping to finish the change before the better half comes home and sees her bike in bits at week's end.