you don't have to race for a living to race in the pro/elite class. And I'll even go further and say how many pro riders have you seen racing on flats?
Well I'm considering moving up to pro/elite for our winter.series as there's no 40+ cat just 30+...
So that would be me, and a few others doing the same On flats
At the end of the day clips are faster for the majority of riders. I find that I can't gate anywhere near as good on flats as clips and it gives me far more than a 'tiny' advantage. You can still easily dab your foot down with clips, you just clip out... If they weren't faster and didn't have any advantage then nobody would run them, it's just they are advantageous so the majority of people do run them
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Even just free riding on my Dh bike when I still had it I was more confident on clips than I ever was on flats. Even when getting mad sideways off jumps.