Like Poguemahone said, the stock UO-8 cups are thin-walled and hence, most spindles will not work, as the adjustable cup will go too far into the frame to get the lockring on. A "5" prefix spindle will work, as the races are further apart on them. They are, however, very hard to find nowadays. The ones I've used have been recovered from old bikes, not bought new. As others suggested, Sugino French cups will work, (I used these on my girfriend's PX-10), but they seem to pop up and then disappear for extended periods of time. You can go the Phil Wood route, but seriously, is it worth spending that much on a lowly UO-8? I guess it depends how much it means to YOU....