I’m Super interested in the Super 9 Disc wheel from Zipp because I’m not above taking pleasure and comfort in being validated. Or vindicated. I assume vindication comes from the same root word as vindictive and I don’t feel that. I just feel that there’s a thread that’s been running through bike design and this wheel is an example of the technical fabric that binds together disc brakes, tubeless tires, wider blades and stays on framesets, optimal tire size and, of course hookless rims. They all work together. None of them work as well when deployed separately. Let’s talk about this wheel.
It’s no more aero than Zipp’s last version of this wheel, so what’s the point? The point: It rolls faster. Why? Because it’s optimized for a wider tire, namely 28c. As we know a 28c tire is less aero than a 25c tire. But… not necessarily. It’s less aero when you just change the tire on a wheel optimized for a 25c tire. It’s not necessarily less aero when you design a wheel specifically to accommodate a 28c tire. This is what Zipp says it did. This is why a disc (or any) wheel that succeeds in not losing aero performance with a larger tire wins because of decreased rolling resistance. Tubeless Rim
“The Super-9 is engineered for a new era of wider tires and lower tire pressure in TT and triathlon,” Zipp says about this wheel. “The ‘old idea’ is that it is always faster to pump up your tires rock hard before a time trial or triathlon. You felt every bump as you almost literally bounced down the road... riders on the Super-9 realize a disc wheel does not have to feel rigid to be fast. The Super-9 is fastest with 28mm tubeless tires inflated to lower than traditional pressure. So, beyond speed gains, riders will experience better handling and cornering on course in a disc significantly stiffer and more durable disc than its predecessor.” As to pressure, the Super-9 comes with the TyreWiz 2.0 tire-pressure monitor integrated out of sight, so riders will always know if they are in their desired PSI/bar range. Inflation “is a breeze” says Zipp (in a double entendre?) with “redesigned pump access” found behind a pump-access port with a sliding door instead of a sticker. The Super-9 is built around Zipp’s ZR1 hub with ceramic bearings.
This is the wheel that Chloe Dygert used when she won ITT Worlds last year and the women’s U23 time trial race was also won by a rider (Antionia Niedermaier) on this wheel. Both women road 28c tires front and rear. Certainly the nonbelievers will point to the lighter weight of women, arguing that that 5 bar max for hookless tires places a rider weight limit on this tech. Just, as another data point Movistar also rode this disc last year and notable is that men’s team’s 2nd place posted in the Vuelta TTT in 2023. The inside bead width is 23mm and that means a 28c tire is even – argghhh! – probably 30mm or so when pumped to pressure. I channel the skeptic with my argghhh! This is the performance set up I’ve been riding for 2 years – a 28c tire measuring 30mm on a wider hookless rim. This disc arrives at a place I already live and inhabit, comfortably.
“Max system weight” is a spec Zipp now includes, and it’s 255lb for this wheel. The means, I take it, a 230 pound rider aboard a 20lb bike and we’ll throw a few pounds of extras on there (gels taped to the top tube, fluid in all the reservoirs, tools, electronics and what have you). Max tire pressure is 73psi (5 bar). But as to that max system weight, for a rider who does actually weigh 230lb yes, it's going to require more pressure than 5 bar to pump this tire for ideal performance. If I were this rider I don't think I'd opt for hooked and 28c (or 25c). I'd ride this wheel with a 30c tire. But I acknowledge the conundrum for this rider using Zipp's tech. This disc wheel weighs just a tick under 1000 grams and will cost you $3,000. It's available with either SRAM or Shimano driver bodies and there is a lifetime warranty on this wheel. There’s a wheel bag and disc protector as part of the purchase.
Zipp also launched a new track disc today and I mention this not because you’re part of the market audience, but because this wheel features a hooked bead built with a 21mm inner bead width. It’s optimized around a 25c tire. This is – to me – Zipp’s capitulation on its road wheel theme. At first Zipp maintained that it’s 23mm inner bead width road wheels were fine with a 25c tire and on this I was skeptical. (This is back in 2020, when Zipp embarked on its current design motif.) I think this track disc of Zipp’s scribes the parameters of utility. When you’re riding on glass a 25c tire is faster and the pressure can and should be higher. This calls for a bead hook in the rim. This wheel has a max tire pressure of 125psi. The de facto road race tire size in the pro peleton is now 28c, and 30c and 32c are what are most commonly used in the spring classics. The last holdout is TT and tri and for good reason: Until the bikes are designed to be optimized around 28c the value of the larger tire size and the wheels to accommodate them are limited.
I spent 2 hours with the folks Quintana Roo yesterday, and we spoke about Shift Technology – that brand’s method of pushing the air to the non-drive-side of the bike through an asymmetrical down tube and that fat non-drive chain stay. Bikes like this – with its wider blades and stays – anticipate larger tires. When you look at BMC’s road and tri bikes released over the last year they anticipate wider tires. Same with Canyon, Cannondale, and you should just expect this from bike brands. There will remain considerable debate about what ought to be. But what you’re seeing with this new Zipp disc is a harbinger of what will be. The cycling world would not be here, coalescing around the 28c tire size for both road and tri/tt, were it not for disc brakes and road tubeless tires. The 28c tire size unlocks the ability to use a hookless rim design. In my opinion, hookless will be the last thing to change. Plenty of wheel brands will resist this. But the 28c tire size, this will become the pervasive tire size for both road and tri/tt. Consumers will become more comfortable with hookless when virtually every performance tire made is hookless compatible (almost all high performance, thin wall race tires introduced over the last 3 years have been hookless compatible). Nevertheless, consumers will accept this design motif at their own pace. You can read more about the Zipp Super 9 Disc wheel here.
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