Cheers Do you want to know what the difference is between a crank extractor and just beasting it off with a hacksaw and a hammer? or something else? Crank extractor: easy to use tool, removes the crank arm with a relatively small amount of effort saves you money as you dont end up damaging your parts Beasting it, (also known as the "give it beans" method) In your way, you cut the bb up, so need a new axle, Hammer can damage cranks, Just alot of effort really. EDIT: just realised the original question. Square taper round off easier, thus making crank/bb useless if that happens. Isis are far harder to round off, as they have alot of sticky outy bits (technical term i know..) Isis cranks just tend to come off easier. Matt