hypermobilty Posted September 18, 2012 Report Share Posted September 18, 2012 How do I take a screw on cog off Which way do I unscrew it Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted September 18, 2012 Report Share Posted September 18, 2012 It's a standard thread, so anti-clockwise to remove It'll take a shitload of force though, if it's been used, since you'll have been putting it under some fairly major torque! Quote Link to comment Share on other sites More sharing options...
hypermobilty Posted September 18, 2012 Author Report Share Posted September 18, 2012 Cheers Any advice on how to get it off without damageing it Quote Link to comment Share on other sites More sharing options...
isitafox Posted September 18, 2012 Report Share Posted September 18, 2012 If it's attached to your wheel then make sure you still have the tyre and tube on inflated to grip it, wrap an old chain around the cog and tighten in a vice then grab hold of the wheel and try to undo it. If it's attached to a crank arm then the same idea but get a piece of bar or tubing a good few feet long and slide it over the crank then use that as leverage to unscrew. Quote Link to comment Share on other sites More sharing options...
Ben Gosden Posted September 18, 2012 Report Share Posted September 18, 2012 You could use a old spare bit of chain wrap it around the sprocket then lock the remaining part of the chain in a vice then grip your wheel and turn anti-clockwise(left) Also if it doesnt take the bait and come off then you could heat it up (in a method of your choice) to a certain degree where it will expand making the sprocket simpler to remove. Hope this helped. Quote Link to comment Share on other sites More sharing options...
hypermobilty Posted September 18, 2012 Author Report Share Posted September 18, 2012 Cheers I'll give them a go I've tried with a chain whip and my lack of brute strength and that didnt do it lol Ive given up know for tonight will carry on tomorrow Quote Link to comment Share on other sites More sharing options...
AndrewEH1 Posted September 18, 2012 Report Share Posted September 18, 2012 In Tarty we trust - this should explain all if the explanations above didn't: http://www.tartybikes.co.uk/media/guides/maintenance_freewheel_and_sprocket_removal/m1.html Quote Link to comment Share on other sites More sharing options...
rocky111 Posted September 19, 2012 Report Share Posted September 19, 2012 In my experience even with a brand new piece of bmx chain, often the chain just snaps, so you either have to grind flats off the sprocket to get it in the vice, or cut through the crank from the inside with a hacksaw in two places then squish it in the vice to get it off. you definitely need a good vice and a long leverage bar at any rate, I guess it depends if it was greased properly when it was put on which they often aren't. Quote Link to comment Share on other sites More sharing options...
JT! Posted September 20, 2012 Report Share Posted September 20, 2012 Cheers I'll give them a go I've tried with a chain whip and my lack of brute strength and that didnt do it lol Ive given up know for tonight will carry on tomorrow Never use a chain whip, they're designed to hold a cassette not for unscrewing cogs. You'll just break it. If you haven't got an old chain, blocks of wood in the vice will work too. 1 Quote Link to comment Share on other sites More sharing options...
hypermobilty Posted September 20, 2012 Author Report Share Posted September 20, 2012 Never use a chain whip, they're designed to hold a cassette not for unscrewing cogs. You'll just break it. If you haven't got an old chain, blocks of wood in the vice will work too. funny enough i broke the chain whip lol Quote Link to comment Share on other sites More sharing options...
bing Posted September 20, 2012 Report Share Posted September 20, 2012 Never use a chain whip, they're designed to hold a cassette not for unscrewing cogs. You'll just break it. If you haven't got an old chain, blocks of wood in the vice will work too. I got mine off my cranks with a chain whip on Saturday morning, bit then the whip is modified with kmc z910 chain and we had a 3ft scaffold tube on the end of it. the crank was in a vice as well. you need to tease it off gently. writhing at it doesn't work. gradual force is the way to get these things off Quote Link to comment Share on other sites More sharing options...
hypermobilty Posted September 20, 2012 Author Report Share Posted September 20, 2012 Thanks everyone for the help I got it off using a chain and vice ) Quote Link to comment Share on other sites More sharing options...
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