Ill-fitting skinsuit, near-empty bottle, not unfavourable wind, regular race bike setup. Got there later than intended which meant having to overtake lots of people and also couldn't go full gas through the hairpins or at the top. Makes me think I could definitely do 5:50 on a closed road with none of those issues! 300w for 6 min is a power PB too.
I should also note that I felt absolutely awful in the first minute or so, and if I hadn't had a powermeter and Garmin telling me it was fast and strong, I definitely would have sat up long before the first hairpin! I'm apparently quite lousy at judging PE for those short efforts.
Well done you! Good job. Awesome power and a very good result in the BH Challenge.