Thanks Sam. Hmmm best part of £100 for a 1mm bigger axle….
That’s not quite my understanding…
I think it goes:
Standard rear dropouts are 10mm diameter and standard front dropouts are 9mm diameter.
Then, ‘normal’ qr hubs have either 10mm (rear) or 9mm (front) stubs (for want of the proper term) that slide into these dropouts – and which the qr fits though.
The qr diameter is (at a guess) between 3mm and 5mm and slides into the hollow axle of the hub. It’s working to hold the axle clamped in the dropouts, but isn’t itself the axle – the axle work is being done by the 10mm (or 9mm) stubs that are resting in the dropouts.
The thru axle hubs that take the superstar or DT Swiss or Hadley thru axles as described above are different in that these rods become the axle as well as the thing that clamps the wheel into the dropout. Hence a front DT Swiss RWS is 9mm diameter, to fit in the dropout – and the rear is 10mm to do likewise.
The extra stiffness comes from the more solid connection between bike and wheel – the bike is more directly connected to the axle.
I think.