How much force needed to remove sprocket?

[neil_p]

I'm attempting to remove the sprocket, using the Rohloff tool, a half decent chainwhip and a bench vice.  Carefully following the instructions on the SJS website (NOTE THAT BECAUSE THE HUB IS INVERTED (SPROCKET SIDE DOWN) THIS WILL MEAN LEVERING THE CHAIN WHIP CLOCKWISE, AS YOU SEE IT, WHEN LOOKING FROM ABOVE.)

However, it just won't budge. The limiting factor seems to be that the weight of the wheel wobbles the hub, and the rohloff tool starts to come out of the vice.... meaning I have to stop and reset it.

Any suggestions?

[neil_p]

Answered my own question.... shed loads! Finally got the sprocket off... phew!

[julk]

How about,
If you can hold the Rohloff tool in place with the skewer fastening it then have a go with the wheel vertical as though it was being ridden and stick a big spanner on the Rohloff tool.
Fasten the chain whip loose end with a zip tie or similar to stop it flying off the cog.
Position so that you are pushing down with a different hand on each tool.
The sprocket then screws off as though you are back pedalling.

Insufficient leverage, put tubes (scaffolding pipes) on the end of the tools!

Curses, foiled whilst posting...

[neil_p]

How about,
If you can hold the Rohloff tool in place with the skewer fastening it then have a go with the wheel vertical as though it was being ridden and stick a big spanner on the Rohloff tool.
Fasten the chain whip loose end with a zip tie or similar to stop it flying off the cog.
Position so that you are pushing down with a different hand on each tool.
The sprocket then screws off as though you are back pedalling.

Insufficient leverage, put tubes (scaffolding pipes) on the end of the tools!

Curses, foiled whilst posting...

Cheers.  I did try initially with wheel verticle, chain whip and an adjustable spanner (always a bad idea!), but was worried one or both would fly off.  Zip-tying the chain whip ends together is definitely the way forward for future attempts.  Eventually sheer brute force worked... simultaneously bouncing the wheel/tool out of the vice... at first I thought I had broken something, so violent was the sudden movement. Thankfully all is ok.

[greywolf]

It takes it bit of grunt, and the odd skinned knuckle, but they do come off. I have never broken a chain whip - mine are home made using old chain and 30cm steel bar. maybe try a tap with the old wooden mallet once everything is in place.