We have discovered that the front hub features a metric bearing setup. Due to a shortage of materials during the Korean War, metric bearings with an o/d of 47mm were fitted in place of the standard Vincent item. So this item is not the original hub as 2751 was completed and shipped prior to the onset of the Korean War.
What to do? Replacing the hub with a new pattern item and fitting standard bearings was one option. Another was finding a period hub and hollow axle and fitting that. The former of these options is the least desirable as we would be replacing period items with new ones. The latter option seemed more in keeping with the level of authenticity we are are trying to achieve but we have decided to go with what we already have. The reason for this is that (i) it’s a genuine period hub (albeit of a little bit later vintage than what would have been fitted to the bike when new) and (ii) was used during the bike’s racing career. In addition, it features a hollow axle machined out of lightweight alloy. These were sometimes fitted to Vincents though we’re not sure whether this one is original or made at a later date. Anyway, it seems entirely appropriate to preserve this lightweight component on a racing machine.