Aero is all the pieces. It’s a mantra that’s been utilized in highway racing for a few years, and gravel racing is catching up –if not surpassing the development– quick. It began with aero bars (which are actually largely banned) and has since made method for developments like skinsuits with built-in hydration bladders, wind tunnel-tested bike baggage, aero chainrings and, as of late, particular wheel and tyre pairings designed round aerodynamics.
With riders now tackling 200–mile gravel programs in as little as 9 hours, pace is paramount, and small aerodynamic positive factors can have huge impacts.
When the {industry} first acquired behind the gravel self-discipline, wheels and tyres had been initially taken from the highway self-discipline and modified for robustness. They’d to have the ability to stand up to the abuse of the tough terrain whereas aiding the prevention of punctures, which led to the blanket adoption of wider, tubeless tyres and rims. Aerodynamics initially took a backseat, and in contrast to in highway racing, most wheels and tyres had been developed independently of each other. Nevertheless, the interplay between tyre profile and rim performs a vital function in aerodynamics.
Think about any race-oriented highway wheel, and also you’ll discover how the exterior rim is ever so barely wider than the tyre, making a flush profile. In gravel racing, although, huge tyres are the norm, with a 40mm being on the small aspect lately. However what occurs if you put a 40mm tyre on a 25mm rim? You get the mushroom look – which, aesthetics apart, hampers aerodynamics and will increase your probability of pinch flats.
Now, extra manufacturers and producers are adopting a holistic strategy to wheel and tyre design. Zipp calls it Whole System Effectivity (TSE™), and with the newly launched Zipp 303 XPLR SW gravel wheelset and Goodyear XPLR tyres, the model hopes to supply proof of an idea many have been working towards: wider rim widths paired with large tyres at decrease pressures should not solely extra comfy but additionally quicker.
The wheelset and tyres had been launched alongside SRAM’s new flagship gravel drivetrain, the 13-speed SRAM Purple XPLR AXS. I had an opportunity to trip it, and you may learn the evaluate right here.
Introducing the Zipp 303 XLR SW gravel wheels:
The Zipp 303 XPLR SW gravel wheels sport a 32mm inner width
(Picture credit score: Jake Rytlewski)
Zipp is definitely not distinctive in recognising the significance of how a tyre profile and rim work together relating to aerodynamics. Over the previous few years, we’ve seen the inner rim width develop from 23 to 25 to 27 and even 30mm. There’s additionally been a rise in partnerships between wheel and tyre producers (e.g., DT Swiss and Continental, Parcours and Panaracer) or wheel manufacturers bringing their very own tyres to market (e.g. Enve).
Whereas Zipp has launched its personal tyres previously, for its latest flagship product, the American firm turned to tyre consultants Goodyear to develop an ideal gravel tyre after which design a wheel round it.
The model known as their collaboration a “strategic partnership to develop industry-leading tyres that embrace rising applied sciences and traits with out compromise.”
Zipp’s ensuing wheel sports activities one of many widest rims we’ve seen but: 32mm inner.
Zipp argues that the mismatch of pairing a 38-50mm tyre with a typical rim dimension not solely hampers aerodynamics, however the rim additionally doesn’t present sufficient help for lateral cornering hundreds on the desired decrease pressures, inflicting the tyre to break down and, subsequently, negating any benefit.
The brand new wheelset and tyre pairing comes with a set of daring claims, together with:
– Quickest gravel wheel round (on gravel)
– A 5-watt aerodynamic benefit over a number one competitor.
– Zipp says that on gravel surfaces, riders can lose as much as 100 watts resulting from vibration. The larger-volume tyres at decrease pressures are supposed to act as a suspension to assist clean issues out and assist riders expertise much less muscle fatigue
– The 54mm deep rim creates the ’good side ratio for aerodynamic effectivity’ with a 40mm gravel tyre at race speeds.
Briefly, the Zipp 303 XPLR SW wheel was optimised for aerodynamics, consolation and flat safety, all meant to assist gravel racers cowl huge distances of tough terrain at pace.
Key options and particulars:
(Picture credit score: Anne-Marije Rook)
- 32mm inner width / max 40mm exterior width
- 54 mm rim depth
- Elevated rim edge most safety from pinch flats
- Hookless and tubeless, designed to be used with tyre pressures beneath 30psi (2.1 bars) / Max tyre strain 50 psi/3.45 bar
- Rim dimensions conform to ISO 622×32 TSS normal however Zipp-recommended tyre sizes (40-60mm) fall exterior of ISO suggestions Weight: 1,496 g with valves and tape ZR1 DB hub with 66 factors of engagement
- Centre locking rotor interface. Aero optimised for a 40 mm tyre and minimal losses with 45 mm tyres XDR, SRAM/Shimano, Microspline, and Campagnolo N3W hub choices
- Launching with Goodyear XPLR tyres but additionally suitable with choose tyres from different manufacturers
- Max System Weight 286lb / 130kg
- Value: $2,100 / €1,800 / £1.600.
The Goodyear XPLR tyres
The Goodyear XPLR ‘slick’ tyres
(Picture credit score: Anne-Marije Rook)
Designed with Zipp, the Goodyear XPLR tyres had been made particularly for –and just for– the 303 XPLR wheelsets. “Goodyear Designed for Zipp’ tyres are the consequence a collaborative strategy to redefine efficiency on the highest degree,” the model states. They arrive in two fashions:
– A 40mm XPLR “Slick” which contains a semi-slick sample with two traces of aspect knobs and a minimally textured center. The quickest of the 2 fashions, the Slick is a lightweight and supple tyre meant for dry days and smoother surfaces. In different phrases: a champagne gravel tyre. Tyre weight 445grams
(Picture credit score: Anne-Marije Rook)
– The 45mm XPLR “Inter” was designed for dry and combined circumstances, with a decent sample of knobs within the centre for quick rolling and aspect blocks for grip and cornering. These had been made for races the place the circumstances could also be a bit extra unpredictable, say at Unbound. They weigh 80 grams greater than the Slick mannequin, weighing in at 525 grams.
Goodyear XPLR “Inter” tyre
(Picture credit score: Kenza Barton Schlee)
These tyre fashions are ONLY suitable with the Zipp 303 XPLR wheelsets. They’re tubeless however could also be used with an innertube if essential. Tyres retail for $80 / £80 every
The Trip
(Picture credit score: Anne-Marije Rook)
I acquired to check most of SRAM’s new top-tier assortment suddenly, as I obtained a Canyon Grail CFR take a look at bike full with the brand new SRAM Purple XPLR AXS 13-speed groupset, Zipp 303 XPLR SW wheels and Goodyear XPLR Slick tyres. This construct makes for a really light-weight but succesful and quick race machine – not in contrast to the bike the reigning gravel world champion Kasia Niewiadoma (Canyon-SRAM) is driving proper now.
Appears are arbitrary, I do know, however the wheels, with their deep dimpled rims, black spokes and matte gray branding, actually do look nice on this bike and would complement nearly any fashionable gravel bike on the market. They feel and appear quick, and that alone offers a sure increase of confidence.
At 54mm, the edges are fairly a bit deeper than most gravel wheels available on the market, which are likely to high out round 40mm. Nonetheless, with a weight of slightly below 1500 grams, the depth comes with little penalty.
In case you’re questioning how a lot of a distinction 7 added millimetres of inner rim width makes to the bare eye, let me let you know: so much. The wheels look completely beefy. They’re considerably wider than the edges on my XC bike and even larger than the Reserve all-mountain hoops on my full-suspension mountain bike. However earlier than you get tempted to throw these in your XC whip to set some new private bests in your favorite path, Zipp warns that these wheels should not for use on mountain bikes. Any use exterior of its meant driving software will void the guarantee, and I’d think about the light-weight construct and sheer quantity of uncovered carbon weren’t made to resist the influence.
The large tyre mattress on the 303 XPLR SW permits for a decrease tyre strain whereas sustaining pace on gravel roads. The wheel additionally has a decrease max tyre strain than most different rims available on the market and depends upon the tyre width. For instance, tyres 40-44mm have a max tyre strain of 51 PSI (3.5 bar), whereas tremendous large tyres measuring 55-64mm have a max tyre strain of simply 36 PSI (2.5 bar).
Since these wheels are in contrast to anything at the moment available on the market, Zipp suggests utilizing its tyre strain calculator within the AXS app. This instrument takes your weight plus that of your bike and gives a steered tyre strain particularly for the 32mm inside rim width and meant terrain (i.e. gravel). In my case, it really helpful 25 PSI (1.76 bar) for the entrance and 27 PSI (1.87 bar) for the rear. It’s not the ultra-low pressures you would possibly see in cyclocross or mountain bike racing, nevertheless it’s nonetheless barely decrease than what I ran at my final two Unbound races.
(Picture credit score: Kenza Barton Schlee)
When it was time to get out and trip the wheels, I’ll admit that I used to be a tad timid at first. I’m not one to shrink back from the rougher finish of the gravel spectrum, and a few singletrack tends to wind its method into most of my native gravel routes. With the deep part rims and the seen rim edge peeking out from the edges of the 40mm tyres, there’s plenty of fragile carbon uncovered to potential rim strikes, rocks, and so on.
Nevertheless, Zipp designed for this with 3.9mm-thick rim edges to maintain the wheel intact in case of influence. Zipp says the rim edge is 77 % thicker than earlier fashions, reducing the possibility for injury ought to the tyre backside out on the rim edge whereas additionally stopping pinch flats.
It’s vital to reiterate that these wheels had been particularly designed for pace and gravel racing and never technical off-road driving. And also you really can really feel the place the wheel is at its most effective. Throughout chipseal and onto clean gravel, the wheels zoom alongside fortunately, consuming up the miles with ease and tangible pace. These wheels are made for these days when you possibly can see huge, undulating hills stretch out earlier than you, with winding ribbons of gravel roads disappearing into the horizon. On the large open groads, you possibly can actually put the ability down and let the wheels carry you throughout the plains, ticking off the miles in private report time.
With the 303 XPLR SW wheel, Zipp has efficiently discovered the uncommon mixture of consolation and pace. And whereas made for gravel, these wheels can be a improbable possibility for randonneurs and different long-distance highway cyclists as effectively. Must you need to take these wheels on an off-road bikepacking journey, nonetheless, Zipp recommends utilizing tyres wider than 58mm /2.28” and maintaining the general system weight beneath 286lb (130kg).
Other than my concern of rim nicks and rim strike, the wheels carried out surprisingly effectively on the twisty stuff, too. The hubs spin up rapidly and the wheels have extra liveliness to them than I’d have anticipated from a 54mm deep rim. They’re steady but simple to deal with if you need to hit corners or assault the descent.
In long-term use, I’d think about the wheels will likely be simple to reside with as effectively, because of the serviceable hubs, exterior nipples and j-bend spokes (that are extensively obtainable).
A observe in regards to the Goodyear XPLR tyres
(Picture credit score: Anne-Marije Rook)
I acquired on very effectively with the 303 XPLR SW wheels however the Goodyear XPLR Slick tyre much less so. It merely wasn’t the precise match for my driving and/or the time of 12 months. “Slick” is a little bit of a misnomer because the tyre does sport a sample of two traces of small aspect knobs and a minimally textured center. Even with the sample, the tyre could be very quick on each tarmac and clean, hardpack gravel. However hardpack gravel was tougher to seek out after an extended and dry summer time. The paths turned unfastened, dusty and rocky, and I discovered myself slipping on climbs and needed to take corners with warning. I’d have wished both extra width or extra chunk. So if you end up on related terrain, maybe the 45mm XPLR “Inter” tyre can be a greater match.
The Slick tyres are greatest reserved for the white roads of Italy, SBT GRVL’s champagne gravel and even Unbound on a mud-free 12 months.
Worth & Verdict
(Picture credit score: Kenza Barton Schlee)
In the case of the value tag, I truthfully suppose Zipp set a really affordable worth. $2100 / £1600 is some huge cash, sure, however applicable in a premium market. There aren’t plenty of deep-rimmed aero gravel wheels available on the market but, and plenty of would have priced their hero product a lot greater.
Trying on the professional gravel peloton, the Enve SES 3.4 wheels that Alexey Vermeulen makes use of, for instance, are lighter but additionally shallower, much less large and retail for $2,850 / £3,100. The DT Swiss’ GRC 1100 Dicut 50 wheels I’ve seen on Paige Onweller‘s race steed sport a 50mm deep rim, weigh 1575 grams and have a 24mm inner width. Additionally they include a $3,000 pricetag.
Maybe the closest comparable product I’ve seen is Parcours’ new FKT wheelset, which can also be a deep-dish aero (47mm) gravel wheel with a wider inner rim (27mm versus Zipp’s 32mm) and an analogous weight of 1500 grams. The FKT wheelset does retail for much less: $1,599.00 or $1899 with a ceramic bearing improve. Biking Weekly is getting a wheelset in for evaluate so keep tuned for that.
Last ideas:
The Zipp 303 XPLR SW wheels are a powerful addition to the model’s top-tier choices. Am I satisfied that each one wheels want a 32mm inner width going ahead? I don’t know. Ask me once more when the tyre market catches up. Proper now, the dearth of suitable tyres is a severe downside.
That apart, Zipp efficiently achieved one thing distinctive with the 303 XPLR SW wheels: they designed a wheel that’s mild but aerodynamic, steady however not uninteresting, comfy but quick, and never outrageously costly at $2100 retail.
For those who’re an underbiker who enjoys technical and rugged terrain, these wheels should not for you. Nevertheless, for those who’re in search of pace throughout lengthy and huge distances, the Zipp 303 XPLR SW wheels are definitely value a glance.