I'm installing a new threaded fork on my old Trek 470. Now, as per usual, the stem is longer than it needs to be, and in theory, I simply need to cut it down to account for the particular headset I have. Now, I'm wondering to myself... Why on earth is the locknut capped? i.e. the locknut is designed so that it can't be screwed down below the top of the threaded stem. I'm very tempted to just replace this type of locknut with a normal nut. There is of course an advantage in the design of the locknut, where it has a rubber seal, and will stop dirt etc from going down the tube. But I'd just throw on an O-ring to act as a (reasonable) seal. I can certainly see that having a cut down stem and tidy locknut arrangement is cosmetically pleasing, but that doesn't bother my. Any ideas/comments?

Regards,

Stuart