Get a helper. In fact, get a team of helpers. One of our team was ill and so ended up pit bitching for us instead in 2008. He said it was harder than riding – constantly washing bikes, lubing bikes, replacing components, cooking for 24hrs.
I'd agree on the A B A B A B C D C D C D at night. We usually start this at 10pm, run pair one until 2am, then pair two 2am – 6am. Being in pair two really sucks as you have to get up at 2am and then can't sleep at 6am when you finish…
Out team takes this:
All my kit, a big water container on wheels (essential), big cooking tent, 1.5" Schwalbe Mud Sharks for when it rains, recovery drink, energy drink, bananas, ham, bread, rice pudding, jam, Haribo, salad, cereal, milk, personal tent, sleeping bag, roll mat, Dirtworker (although with Mayhem mud you may as well piss on the bike with one of these), Petrol powered jetwash (copes with Mayhem mud rather well), spare tyres/pads/wheels/helmet/shoes/bars, gels, energy bars, lighting for the main tent, generator (although we've been hooked up to the arena supply recently), huge flag for marking where you've left your bike after the run, LIGHTS, charger, paddling pool (works great as an ice bath recovery dip), lap timing board.
I've now done something like 20-25 12&24hr races, 15 with the same team, and still love it. Last year we managed to podium at Mayhem and SITS – this year I want to win a King of the Night… We've got it pretty polished after 6 years of racing together. You can bet one someone having a crash and wrecking the bike at some point. Last year, our team got through a set of wheels and a pair of bars. The unpredictability makes these events what they are.
One thing you will definitely need is a sense of humour for when it rains. Yes, it's crap. Yes, you're going 5mph. Yes, you've had to run with your bike more than ride, but so is everyone else and it's just brilliant.
GB