So who saw the ITV4 Chris Boardman piece recently about putting sealant in tyres? (and pondering why the pros don't do it).
Were they showing tubeless, or old-fashioned clinchers with sealant added?
They were showing tubeless I think. He was pondering why it was that the pros wouldn't want that extra watt or two in return for such puncture resistance. I can think of a few reasons;
1) pros have spare wheels and spare bikes readily available. Once or twice a season, a handful of riders (with something to lose) run a risk of being genuinely delayed in a stage race by a puncture on a narrow road, because of poor race service.
2) it is probably a greater loss than most folk suppose, or that testing on rollers shows; in the real world (rather than on Crr testing rollers) the whole wheel is jiggling up and down over bumps and the losses are likely to be greater under these conditions.
3) the whole setup is appreciably heavier than with tubs
4) in the event of a flat (and you will still get them), tubs are a known evil, handling wise. Tubeless, not so much.
5)it runs contra to the ethos of 'marginal gains' prevalent in pro cycling these days.
You might just as well ask why it is that the pros don't add sealant to the tubs they use at present; it would work as well, pretty much, and would be a fair bit lighter (for any given strength etc).
Arguably you could make significant gains in bike reliability by ditching electric gears; since they were first adopted in the peloton, I don't think I've seen a major race where no-one had a 'duh, no gears' moment.
cheers