Tailwinds don't explain anything for steep uphill segments. The segment I'm about to describe begins with a very tight turn that immediately ramps up sharply, no way to carry much speed into the beginning.

The other night I was happy with my PR on the 1.5 mile segment with a 3% average grade. The top 3 guys on the segment were well over 1 minute faster than me. Yep, I'm an old guy but the top 3 guys, all of whom I know and ride with regularly, are absolute beasts, and are among the best in the country.