Hi,
Im changing the chain and sprockets on my bike and i easily got the rear sprocket and chain off
but when i removed the front sprocket cover, removed the retaining washer and nut the bloody thing wont come off.

it sits on a splined shaft and from what i can see its rusted on,
i have soaked it in WD40, tried a rust removal acid, bashing it, pulling it and even tried a 3 arm and 2 arm puller all of which wont budge it.

any ideas on how i can get it off??

It would seem that concentrated heat is the most likely option prior to then using a puller, but great care would be needed in its application. DEFINITELY not something to be undertaken if not totally skilled in using a torch or blowlamp in such circumstances.

i have an 840w blow torch but was wary cos of the seals and the various plastic and heat sensitive parts around the sprocket. on the plus side tho it is a pencil torch so its not too wild. reluctant to use it tho

The only other suggestion I can offer you at this time is to hire, buy or borrow a hydraulic puller, if indeed you can get one small enuff to do the job.

You could try Enerpac

Or one of their Main Distributors,

This one is known personally to me and you should find them extremely helpful. Ask for Mr. Graham Mullen and seek his advice

Hi-Press


Anyway best of luck :pwq

I would try tapping the sprocket on opposite sides of the shaft to try to rock it free. Dont hit it too hard - to avoid damaging the shaft itself.
If that fails - then warming it up - start near the outside of the sprocket with the heat - so that you arent applying heat to the shaft - and hence damaging seals.
hope this helps.
:D