It looks like you may have sold it already but a/c refers to the axle to crown measurement of the fork. I have a fork that's 385mm axle to crown and if this frame is designed for a 400mm a/c fork it wouldn't be suitable. Cheers.
Ah. Well, the fork I had on it was a road fork, and it was built for a (slightly longer) Audax fork that would accept mudguards well. So I reckon a slightly longer fork would be correct, even though a shorter one worked fine.
It looks like you may have sold it already but a/c refers to the axle to crown measurement of the fork. I have a fork that's 385mm axle to crown and if this frame is designed for a 400mm a/c fork it wouldn't be suitable. Cheers.