I bought a Yamaha XS850 with 8K miles.  Over the last 2 years, I've put 30K
of commute miles onnit.  Valve adjustment intervals are suppossed to be every
5K.  Well every 7.5K or so, I've checked the pad clearences, and they never
change!  If anything, the clearances seem to be getting a little smaller which
makes no sense to me with the pad system - the pads should wear until the
clearances are too great right?  I know that threaded adjusters can tighten 
up, but I didn't think these kind could.