nuffink stopping you doing that with your buddies, setting up a facebook page/group type thing and making your own guidelines on official start lines and finish lines etc, timing regulations.
as long as its considerate to other swinley users then if you’re having fun, whats to stop you? 🙂 i personally wouldn’t like to be rolling down the deer stalker to have someone rush up behind me shouting ‘get out the way i’m being timed’
not sure if gorrick/BOB would have any objections? pretty sure there’s a few members on here that might comment 🙂
EDIT – me and a few riding buddies have a set loop we all know and sometimes we keep a note of our timings for the whole loop or from the start to certain points, keeps it competitive but fun between buddies, but the main thing is just enjoying being out with those buddies!