Joined: Oct 2011
From: Melbourne, Australia
The front sprocket is exceedingly tight from the factory and requires lots of effort to undo the first time (I've had three gen 4 zx-10rs). An impact wrench and a short air hose are often necessary to get that first one undone. I know of people who have cut theirs off in desperation!
A mechanic changed out my first front sprocket on this current bike but he had to move his compressor to right next to my bike to reduce the pressure loss from the air lines in his shop. What alarmed the hell out of me though was that when I then subsequently changed the front sprocket myself, after deforming the washer, the nut was finger tight! Seriously! It undid by hand!! I had words with the mechanic and vowed to never use them again. Fast forward to the next chain/sprocket change and exactly the same thing happened: the front sprocket nut was again *finger* tight. And I know that I torqued it up to precisely the right setting with a Warren and Brown torque wrench, rear wheel held in place by a block of wood through the rear wheel and the washer properly deformed.
So, what's happening here? I'm not sure, but something to watch out for. And yes, I cleaned the thread on the bolt and inside the nut too in case of any binding.