Can anyone give me some hints on how best to undo the sprocket nut on an R1? I've tried on and off all day but either just turn the gearbox or the ratchet slips off (and, quite franlkly, the resulting idiot rash on my knuckles is going to make me cry before long!)

Cheers

windy gun, or impact wrench.

Just taken the one of my Hayabusa, and the impact wrench I have, (14.4V Makita), only just did it. And even then after four or five attempts. They are torqued to around 150nm.

They usually have a bit of thread locker on them and need a bit of heating up.
I cheated and took it off whilst the engine was in the frame with the chain still on.

it is not a wrong hand thread is it and you have been tighting it up?

I wondered about that, and have tried it both directions.

No luck yet!

I made a tool to hold the sproket whilst I un-did the nut.

Nothing too complicated, two long bits of 25mm box section, each with 2 x 10mm holes drilled in the end, so I could get a bolt through that lined up with the teeth on the sproket. A single bolt holding the other end together and a bit of threaded bar about 200mm from the engine to provide some clamping force.

Hope you see what I mean.

Can draw a sketch later if my description is crap.

Mike

Nope, they're a standard right-hand thread.

As Guinness said, you need to hold the sprocket. But whatever you do, do not wedge anything against the crankcases or you WILL crack them!

If an impact wrench won't budge it, a chisel on the sprocket nut can sometimes do the job - a new nut is £3-4 from Chapmans.

I think I understand what you're getting at - it crossed my mind at the time, but found myself reaching down with my fingers, then realised the day could get a wjhole lot worse if I did!

Have you bent out the lock washer tabs?

Yeah, but I didn't immobilise the sprocket itself. I'll give that a go tomorrow and see where it gets me.

its bloody hard when the engine is out of the bike, ive got to do mine soon. Failed once last year, now its crunch time!

impact gun definitely, did mine the other day, undid first go

Carl

ISTR my first one came off with the impact wrench - didnt budge for ages then out of the blue flew off. Might try that now actually!

All great if you have an impact wrench!

I'll skin my knuckles a few more times before I submit to purchasing more tools (desperately saving to get my calipers recon'd properly - the only major things that holding me up on the whole car really!)