Sometimes odd posts pop up with searches including Google Searches.

But, choose a sub-forum.
Go to the bottom of the page.

Choose:
Show Threads from the Beginning
Sort Threads by (choose Thread Start Time or Last Post Time)
Order Threads in Ascending Order.

The first thread in the Road Bike Forum appears to be a 1999 thread:
http://www.bikeforums.net/road-cycli...er-1200-a.html (with a 2005 response).

Are other sub-forums older? 497 seems like quite a large topic number.

There are a few that have an older last-response time. For example the Spandex Thread from May 2000, but unfortunately it has been locked so you can't dig it up from the dead.

I suppose the question is whether one should resurrect an old thread vs a new one.
If someone from 1999 asked what bike they should buy (in 1999), then one should either suggest a vintage bike, or leave it alone.

There, may, however, be a benefit of bringing up what seems to be a reference related thread for further comment. So, if one is curious about derailleur threads, 10x26tpi vs 10x1mm, then it might make sense to append a comment to an old thread.

Something like this safety thread has some general interest, and one gets new members, but it could probably be left to die.