Gareth Winter

When I worked with Team Sky, the team raced 23 mm Veloflex tubulars at over 100 psi on narrow rim-brake rims. For that era it was right: tight frame clearances, narrow rims to fit the callipers, and a latex tube sewn into every tubular. Tubeless couldn’t work at those pressures, because sealant gets blown out of a hole before it can plug it.

Rims and tyres are wider now, pressures are lower, and sealant has time to work. That leaves the tube as the slow part: a second tyre rubbing inside yours. On the same Continental tyre, BicycleRollingResistance measured a butyl tube costing about 2 W per tyre at 100 psi and almost 4 W at 60. And because tubes pinch-flat when soft, you pump them hard, which on a real road is slow.

10+ years ago the Tour was raced on 23s. In 2026, the most common size was a 30.

I run the @silca_velo Protocol RCR. Against the GP5000 S TR in the same width (BicycleRollingResistance): wet grip 83 against 70, tread puncture score 44 against 34. The Conti is 1.8 W quicker on the drum and 25 g lighter. Not the fastest tyre in the world, but faster than most and grippier than almost all of them. On British roads, I’ll take that. Because real roads are not perfect drums in a lab.

Rims not tubeless-ready? Run latex or a good TPU. FYI, I still run tubes on some of my bikes; it’s about context.

Butyl, latex, TPU or tubeless? One, two, three or four. Save this before you buy your next tyres.

#marginalgains #cyclingtips #tubeless (gifted)