I’d say take both bikes as well, that’s what I do, a Rohloff and a SS, so maintenance isn’t too much of a problem for me.
I’ve had a tyre bulge after hitting a rock and had a pedal insert come loose in a carbon crank.
It’s so much easier to swap a wheel or a complete bike than faff around trying to fix stuff like that when you just want to be out on the course riding.
WCA, you must be younger than me. 😀
I’ve got Erlestoke 12 and Bristol Bike Fest on consecutive weekends, followed two weeks later by Mountain Mayhem, all solo. There’s no way I’m going to be fully recovered between events.
Brassneck, as a rough guide to distance, 145 km in 12 hours got me top third at BBF, 190km in 24 hours got me top half at SITS.