I have a personal record on London - Box Hill 2.9km in 8’ 06" with 311Watt average done past 26th March but yesterday I have done the same climb with a very slow friend in a meetup with the stay together feature enable, I completed with 302watt but in 10’ 49". The weight is well configured. Why 2’ 43" of difference ?
I would assume that your friend’s power/speed brought the average down for the two of you.
the problem is that I’ve really run for 10’40" with 302w … I should complete in around 8 minutes
But the stay together feature averages your power I believe.
So if you were putting out 300 & your mate was putting our 200 you travel at a speed equivalent to 250w.
this make sense ! so never run with a low power friend or your climb will never end