Thanks disco stu, I've tried to get a 10mm allen key in there but it doesn't fit, when I look in the void where the axle was (centre of the free hub) it appears totally cylindrical I can't see any flats that the allen key can work from even if it did fit, am I being totally thick and missing something?? Out of interest if i were to get the 7 speed off would 9 speed shimano free hub body fit in its place? Thanks again. I have got another set of wheels aI can use on the build but was keen to re use the original mavic rims. Cheers