I replaced my chain around the 40-45,000 mile area, and the sprockets and chain tension-er parts were in great condition.
Unless the bike was really abused, I don't think the front crank shaft bearing, or cam bearing is going to be in need of replacement.
These engines are good for over 100,000 miles before any real attention is needed for the 'bottom end'.
The reason I replaced mine then, was because of a vibration I had, replaced the chain, no help, it was the beginning of the transmission bearing issues that were brought on by water in the transmission.