I've a Formula hub on the back of my Marin which has worn out bearings.

I'm trying to remove the freehub body from the hub itself without any success, I've tried looking for a hex fitting in the axle, but all I can see is what appears to be a lockring around the free hub with four indents punched in the surface.

Has anyone else here had experience with servicing Formula hubs? If so, will loosening this lockring free the freehub?

The ones i've done have cartridge bearings at each end, removing the locknuts and tapping these and the axle out allow you to access an 11mm fitting from the brake side(incredibly tight usually, and while you'll be very lucky to find an 11mm key, a 7/16" measures the same)

Many thanks for getting back to me.

I've got a bolt through axle so no locknuts as such, although I did try tapping the axle through with no success. I'll see if I've missed anything and will try revisiting the axle again.

Given that my bolt through is 12mm I'll check from the brake end of the hub and take it from there.

The axle will be stepped, so the bearing will have to come out with it, requiring a good hit, support the hub shell when you do this. If it's a 12mm axle then it's not going to be an 11mm key needed either.Did a BMX hub with something similar recently, but can't remember what size key was needed.