My 03 is at 55,000kms or 34,000 miles and is still running strong.

Masrapido had close to 100K kms/ 62K miles when his 750(?) engine went If I remember right.

1 MILLION miles . Or something .
Wasn't that dude in Cali with 100k on a 600 ?
Taken care of , it will last plenty long enough .

Lifespans vary highly depending on the duty cycle, level of maintenance, how long the bike is ignored/not-ridden, and quality of the oil used.

We did have a rider who hit 100k miles in 4-1/2 years or some such, and his was still going strong (California, primarily commuting to work). Based on his level of maintenance and the way the bike looked, I wouldn't be surprized to hear that he got 160k miles out of it before it was ready for replacement of the engine (or the whole bike).

British dispatch carriers (think paperwork delivery guys) usually get around 120-130k out of them before they're ready for the trash-heap, but they ride all year round, including through the snow & salt of the winter. Again, three to four years of back-to-back riding.

On the other hand, I've seen a lot of them go toast around 25k - 45k because their latest riders wrung their poor necks like there was no tomorrow (esp. 2nd gear failures) and skimped on maint (or did their maint wrong -- broken valves, excess blow-by, cam slop, etc.).

Neglecting the bike, such as leaving it parked for months/years at a time, and skipping or stretching maintenance intervals are a good formula for an early death by comparison.

Cheers,
=-= The CyberPoet

Also depends on what you define as major work. But really if you change the oil regularly, keep up with scheduled maintenance, don't beat it all to hell every time you ride, let it warm up before riding, and just generally take care of it, there's no reason you can't do 50,000 miles + without even thinking twice about it . Ive seen and read about guys who have 75,000, 100,000 miles, and still going on their bikes.