There is some variation in the 24-hour races. I gather some are more competitive than others. Anyway, if you're not in it to win it, go for it. You may be one of the slower ones there, but no reason to avoid it, either. It'll definitely be a learning experience.
I think more training probably helps more in dealing with problems that come up rather than just building muscle and stuff. If you've ridden through rain and through heat and got cramps and fixed them and spent hours riding in the dark and rode on rough roads and smooth roads, you're better prepared for the event. There are people that are excellent athletes and don't know how to fix a flat, and that's not a good combination.
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"be careful this rando stuff is addictive and dan's the 'pusher'."