file down either two sides of the axle so that you leave enough thread or widen the dropout. it really depends on what you think is more worth preserving. i have done both and both worked fine. the first time i did it, the hubs were not very good so i didnt care that much. it doesnt actually fuck them up, but if you want to resell them, then this might remove from their value. that sorted the problem really well.
but then i got some campag pista hubs that were in really good nick so i didnt want to mess up the axle in case i wanted to resell in the future. looking at the zenith price (21pounds) i would do that because the chrome might be harder and its easier to do a clean job.
file down either two sides of the axle so that you leave enough thread or widen the dropout. it really depends on what you think is more worth preserving. i have done both and both worked fine. the first time i did it, the hubs were not very good so i didnt care that much. it doesnt actually fuck them up, but if you want to resell them, then this might remove from their value. that sorted the problem really well.
but then i got some campag pista hubs that were in really good nick so i didnt want to mess up the axle in case i wanted to resell in the future. looking at the zenith price (21pounds) i would do that because the chrome might be harder and its easier to do a clean job.