Thanks to all for the info.. I have a 97 R50 and the manual says to change the belt every 100.000kms (60.000mi) I changed mine with 110.000kms and the old belt is perfect. I also changed the water pump (Its the original that came with the truck) that was in perfect shape too... But you never know until you take all apart. BTW I put a new Gates belt.
I had only one problem. When I first started her, it began to leak coolant from below the lower timing cover. I let her warm, stopped and when I came today to take all apart again to correct the leak, I started her again and no leak ???? It's supposed to be normal or maybe the gasket needed to settle with some heat???
Sorry for my poor english!!
Diego from Argentina