A Claud Butler of that vintage will have been built for 27" (ETRTO 630) wheels with 1.25" tyres and mudguard clearance, so probably 63mm or so brake drop to the original wheels. If you swap to a modern 700c (ETRTO 622) fork made for short reach brakes, say about 43mm, you're cutting something like 24mm off the axle to crown length of the fork, which means your top tube will slope down noticeably once the bike is built up, and the head and seat angles will be steepened by about 1.5deg. Aesthetically, you will also have a significant mismatch in clearances front to rear. In short, keep the stock fork and invest in one of Tektro's lovely long reach brakes. You'll even be able to use decent sized tyres and mudguards, which will make winter a much more pleasant experience.
I was hoping that wouldn't be much of an issue. Anyway, I will keep the original forks for the moment. Then I will see once the wheels arrive. If there is a problem, I will use the original forks instead, and get some long reach brakes.
@Feng
I was hoping that wouldn't be much of an issue. Anyway, I will keep the original forks for the moment. Then I will see once the wheels arrive. If there is a problem, I will use the original forks instead, and get some long reach brakes.