He means that a track hub will have two threaded surfaces on it. The first lot of threads - the ones closest to the centre of the hub - are for a cog. But then there will be a little "step" down to a second set of threads for a lockring.
If there's only one threaded surface and no "step", the hub wasn't intended for fixed wheel use.
He means that a track hub will have two threaded surfaces on it. The first lot of threads - the ones closest to the centre of the hub - are for a cog. But then there will be a little "step" down to a second set of threads for a lockring.
If there's only one threaded surface and no "step", the hub wasn't intended for fixed wheel use.