I recently came across a tip to use a piece of old inner-tube to create a barrier against dirt, water and salt for the bottom part of the headset, so I thought I’d try it out while replacing a fork on one of the bikes in the bike library.
With the fork and bearings removed from the head tube, simply pull a section of inner-tube on, leaving some hanging below, then carefully trim it so it doesn’t touch the fork. Then fold the bottom of the rubber up (carefully – you don’t want to move the whole piece) and out of the way while you work. It can be folded down again after everything’s back together and the adjustments are all made.
I think I’ll do this to Ol’ Nelli next time I overhaul her headset, which, due to its poor quality (it’s pretty shot) and unusual size (difficult to replace), will probably be soon (again, sigh). I hope a little rubber can be enough to change my twice yearly headset overhauls into an annual event.