While the road racing season begins in the sun of the Tour Down Under, and amongst the dunes of the UAE Tour, for most fans, it doesn't really begin until the peloton charges up the Muur van Geraardsbergen at the pointy end of Omloop het Nieuwsblad.
The opening race of the Spring Classics was won by Søren Wærenskjold of Uno-X and Lotte Claes of Arkea B&B Hotels respectively, and while the racing is the main attraction, for tech-hungry cycling fans it’s also a chance to see some of the latest innovations for the season ahead.
One such innovation was Tom Pidcock’s integrated tyre pressure sensors built into an unreleased set of Zipp wheels. Based on what we know of these sensors from patent information, along with our knowledge of previous systems, these should have given the Englishman from Q36.5 live data on the state of his tyres, which could prove critical over the rough and tumble of cobbled racing.
Tyre pressure systems are nothing new though, and in recent years we’ve seen several options trialled in racing, or at least in race recon. For one reason or another, these have yet to take off, either amongst the peloton or in the wider cycling community as a whole. On reflection, I think this latest system may actually buck that trend and it could well be something we see far more frequently.
Pidcock’s tyre pressure Zipp wheels
Pictures of Pidcock’s wheels are useful to understand what is going on here, but they are often a little hard to dig into. Luckily, for any new product, patent information is publicly available. Before we dive into the patent itself it’s important to understand the SRAM brand family.
Under the SRAM umbrella comes SRAM components (surprise surprise), but also Zipp wheels - used by a number of top-flight teams - and Quarq. For those not totally familiar, Quark is probably best known for producing power meters - now integrated into some SRAM cranksets - but also it produces the TyreWiz, a standalone tyre pressure sensor that attaches over one’s valves and provides a live readout on one’s cycling computer. Putting two and two together, it isn’t a great leap to assume that SRAM is now integrating the tech it has acquired from Quarq and building into a new set of Zipp wheels.
Looking at the patent diagrams it appears that the new Zipp rims feature a slot into which a tyre pressure module, powered by a coin cell battery, can slot. The module appears to slot on top of a threaded valve tail. Based on what I know having used the standalone TyreWiz, it’s likely that the module will screw into a valve tail, with a valve head screwing into the top of the pressure sensor, with the whole unit then acting just as a normal valve would.
The current TyreWiz is tubeless compatible, so I see no reason to suggest this latest system confines Pidcock to inner tubes.
This system is the latest in a line of real-time pressure monitoring and adjustment systems and, despite being used by Marianne Vos to win the gravel World Championship last year, I think this latest system is the first one that has the potential to actually gain traction. In order to understand why, it’s necessary to explore those systems that have fallen by the wayside.
Systems that haven’t caught on
Besides Quarq’s TyreWiz, there are a pair of systems that have hit the road under the wheels of pro riders. The Scope Atmoz system and the Gravaa system both operate in broadly similar ways, and the latter has, as mentioned, been used to net Marianne Vos yet another rainbow jersey.
Unlike the TyreWiz, the Atmoz and Gravaa systems are monitoring and adjustment systems, meaning at the press of a button, riders can inflate their tyres on the move. How this works is that the rear hub contains a large volume of compressed air in the case of the Atmoz, pumped up in advance of the race, or an integrated battery-powered compressor in the case of the Gravaa. One button drops the pressure of the tyres by simply opening the valve, while another opens the valve from the hub chamber into the tyre, topping it up with air as needed.
The reservoir of compressed air in the Atmoz hub is finite, however. Early uses will also likely be faster than those when the tank is nearly depleted and the pressure in the hub is more or less equivalent to that of the tyre. Use it all and you could just be left with too-soft tyres and no way of inflating them. The Gravaa is only limited by the battery life, and is lighter (600g/21oz versus 450g/16oz per wheelset).
These systems are also expensive (£3,495 for the Atmoz and a £1,619 upcharge for a Gravaa equipped set of reserve wheels), complicated, and not the most visually pleasing, involving as they do a hose snaking down a spoke at the valve.
Why pressure monitoring beats pressure adjustment
The simplicity of even a standalone pressure sensor, regardless of whether it is integrated into a rim or not, has some key advantages over an active tyre pressure adjustment system. First, it is cheaper: A pair of Quarq TyreWiz sensors will set you back in the region of £130/$120. This is orders of magnitude less than an Atmoz/Gravaa system, and when scaled up to rolling it out across a whole team - even just for the riders’ #1 race bikes - that’s a huge cost, either for the team or the manufacturer to bear.
As discussed above, the limited size of the reservoir of an adjustment system does hamper things. Let's say you’re undertaking a race like Paris-Roubaix, you can’t go adjusting your pressure up and down for every cobbled section or you’ll run out of air. Saving it for Mons en Pevelle or the Carrefour de l'Arbre means lugging around a heavier rear wheel for the preceding and latter cobbled sections in the hope that it makes a difference at a key moment.
Aerodynamically the adjustment systems are also suboptimal, but more than that as tyre clearances on the best road bikes increase, along with the slow understanding that wider tyres at lower pressures are actually faster, the need to be constantly changing pressures is falling away.
A tyre monitor built into the rim is the most aerodynamic way of adding some performance value, and while it may not be able to add air in the event of a flat it could well alert a rider to the slight loss of pressure that could precede a total, slow flat, allowing them time to get a wheel at an opportune moment rather than waiting until disaster has well and truly struck. Maybe a slightly smaller gain, but with a lower weight and superior aerodynamics it’s got very few drawbacks from a performance point of view.
Why this system might actually catch on
While it is currently being beta-tested on the road I think the key thing to remember is that Zipp’s wheels are surface-agnostic; they’re generally rated for road and gravel, and what with the ever-ballooning popularity of gravel, both in terms of racing and recreational riding, I think we are just as likely to see this system at gravel races than at road races.
With the greater volume of air in gravel tyres it’s harder to notice if they have gone a little soft, perhaps after a little burp under hard cornering, or a puncture that has sealed, but only after a slight loss in air volume. With an onboard sensor in one’s wheels it could ameliorate those ‘have I got a slow puncture’ demons in one’s mind over the course of a race, or signal that, when the opportunity presents itself, whacking a jet of CO2 in mightn’t be the worst idea in the world.
More than any performance gain I also think this system might gain traction simply because it looks, at a glance, like any other wheel. Cyclists, whether on road or gravel, are sticklers for aesthetics, and while the TyreWiz sensors may be useful in some situations they look clunky and are more prone to lateral forces - I snapped one myself while pumping my tyres up. This, as long as they aren’t a ludicrous upcharge, is probably going to be key to their success.
Finally, there’s the fact that you might just not get a choice about whether you have them or not. We’ve seen the release of Sram Red include a Hammerhead Karoo bike computer, whether you need a bike computer or not (Hammerhead is also under the SRAM umbrella), and leaked images of the latest SRAM Force groupset appear to indicate that the same will be true there in an effort to lock more riders into the SRAM ecosystem. It is entirely possible that, instead of being an add-on, or an aftermarket set of wheels, this becomes the norm across SRAM’s road and gravel wheelsets, at least at the higher end for now.
