The only one I've got a time for immediately to hand, is the July one this year, which was the "Genteel Ride". On that one, according to my GPS, I got to Brighton Sea Front at around 8-15 BST (having left HPC at 00-05 BST or thereabouts). I think I was near the front for arrivals at the Madeira Cafe on that ride.
Generally we'll probably arrive nearer 7am, although with 60 odd people, that will inevitably slow things down a bit. It just takes longer to regroup that many people, we are likely to have more fairy visitations, and the mid-way stop takes longer.