It's rare.
300W for full hour, I know one guy who can well exceed that and he's a pro triathlete, won our national medium long distance last year here in Croatia, and another guy who is roughly there or slightly above and he tends to clean house at bike leg of triathlons he goes to,then this cat1 who rides without a PM but can do it judging by his speed and another who can probably do it and definitely put out some impressive numbers 4-5 years before when he was more active. When we did a local kinda semi-legal hilly 30km TT back in spring, the pro triathlete guy won by as many minutes as was the difference between the cat1 and us middle placed guys.
That's about it. The other 30 or 40 guys I personally know who race either in triathlon or road, can't. A couple of the bigger guys probably could do it and can put put some high numbers in 20-30 minutes, but I don't think I’ve seen them go at it for a full hour and in terms of power to weight (or power to drag even at their height) they're not that special. While a hour at sweetspot is fun, even, you have to really want to hurt yourself to ride at threshold for a full hour.
Last edited by Branko D; 02-13-21 at 02:36 AM.