Why It’s Time to Embrace Hookless Technology for Your Curly-bar Bike

Tubeless tires on wide modern rims will give you performance gains

In April at Paris-roubaix, a Movistar rider’s rear wheel punctured on the cobblestones of the Arenberg Forest. “It’s something we know is going to happen at Paris-roubaix because that race is out of the ordinary,” says Nathan Schickel, product manager at Zipp wheels. “The rider did what all pros do: he continued to ride, looking for team support.” At the end of the sector, the rider found a member of sram’s Racing group. There was a quick wheel change so the pro could continue on with the race. Later, a crack was found on the rim. Again, not a surprise. But what was notable was that the tire, which was tubeless on a hookless Zipp wheel, still held roughly 20 lb. of pressure and was still seated on the rim. For Schickel, one of the biggest misconceptions about hookless rim technology is that it's not as safe as hooked rims on the road. The Roubaix story shows that even on the most extreme roads, if you can even call the sectors of pavé “roads,” a hookless setup can keep a rider rolling.

When you pump up a tubeless tire, the maximum tire pressure is 73 p.s.i. Schickel understands that that number may seem strikingly low for longtime roadies and track riders.

He remembers when he started riding. His first race in 1985 was on 19c treads, which he pumped to 130 p.s.i. Today, the 240-lb. rider (he jokingly says that he “represents big”) runs his tubeless tires at much lower pressures. Schickel played around with the sram axs tire pressure app, which recommended around 70 p.s.i. for his 28c front tire and 72 p.s.i. for the rear. “But it still felt too hard, like they were overpressured,” he says. Now he finds around 65 p.s.i. works best. But why is that?

Take Zipp’s 404 Firecrest Tubeless Disc wheels, for example. They have an inner rim width of 23 mm, which is much wider than a traditional hooked rim for a clincher. “On an old rim, the ‘legs’ of the tire were squeezed in and it was shaped like a lightbulb,” Schickel says. “As you move the legs of the tire out and it gets more of a U shape, that changes the way the tire works. The tire casing becomes more like a spring and actually provides some suspension. Moving the tire hooks out also increases the total volume of air. Both of those things give a ride feel similar to a higher pressure at a much lower pressure.” In short, wider is better.

Schickel is continuing to experiment with hookless rims and tubeless tires. In the spring, he ran a 28c tire on the front and a 30c on the back, both at 65 p.s.i. He knew the wider tires would give him a lower rolling resistance. He took that setup on a fast local group ride and found he could take the corners with more confidence than before, and seemingly with more confidence than other riders. He now calls that setup his secret weapon. It likely won’t be a secret much longer.—