Originally Posted by
HillRider
The radial difference between 27" and 700c rims is 4 mm so, if your brake shoes can be lowered that far, the wheel swap is feasible with no brake replacement. I assume your 520 has cantilever brakes so see if they will adjust as needed.
My 620 has DiaCompe 500G sidepull brakes. That's the same as on the 400, so it may be possible. If I switch to 700C rims, I'll probably just try it out and see if I can keep the same brakes or not. I'm really more concerned with whether the DiaCompes will work with brifters -- my admittedly poor understanding is that brifters generally work poorly with generic brakes that aren't matched to them.