Do people's normal riding gear not normally contain a first aid kit (twinned the the knowlwdge obviously). No matter where you ride, Peaks, trail centre, I find that worrying.
I've said it before and I'll say it again – I'm always amazed how ill prepared bikers seem to be compared to walkers. I'm not saying take a bivvy bag, but a warm/waterproof top, yes. And some idea of the route you are following and the ability to use a map and compass.
In a group this big, if someone does break an ankle – i'd hope there'd be plenty of volunteers to carry the person and their bike to safety.
I'm taking normal stuff and burger cash.