I have a set of the new 303 Firecrest disc wheels and have noticed that rear ZR1 hub width appears to be out of spec (12 x 142) measuring actually 143.2 mm. With this I need to re-adjust the rear caliber (Red AXS) every time I swap wheels to avoid rubbing.
Comparing with my other wheels the difference seems to be on the non-drive side cap. I took the hub apart and checked that caps and the axel fit snugly and re-measured the stack with the same result.
The end caps correspond to the ones on Zipp spare part catalogue as does the XDR freehub. (The wheels were initially delivered with an incorrect 3-pawl freehub, but after I spotted this, the shop replaced it with the correct one…)
The other wheels I have (DT Swiss, Roval, Hunt) measure pretty accurately 142 mm, so I would be grateful if somebody could measure their rear hub width to understand if it is just my wheel.
I would be expect Zipp hubs be accurate to better than few tenths of mm like the other wheels I have.
Other than this they are lovely wheels and I run them with Schwalbe Pro One TLE 28 mm.