Join Date: May 2004
Location: Toronto, Canada
In my experience, as long as the chain is not showing signs of distress (No sticking links, no major change in slack as you turn the wheel with the bike on a stand, and the chain is not needing frequent slack adjustments) it's good to go.
I just took off a DID ERV3 520 from my street ridden bike, which had about 30,000 km on it.
Helibars, MRA screen, Ohlins damper, reversed shift pattern, sorted suspension, braided lines, Michelin Pilot Power, all else stock 'coz it's fast enough!