The Zipp 303 family of wheels needs little introduction; widely regarded as one of the best all-rounders on the market. It’s a wheelset that has tasted victory over the cobbles in the Classics as well as summit finishes in Grand Tours.
Its 45mm rim depth means it strikes an ideal middle ground between low weight, practicality for real world use in varied conditions, as well as being honed for substantial aero gains.
Owning Zipp wheels bearing the iconic 303 moniker used to come at a high cost. And justifiably so, Zipp is a premium brand, and its top end wheels are all still entirely made within its own facility in Speedway, Indianapolis, USA.
But for the 303 S Zipp has gone to the far east for its rim production for the first time. Not just to any old vendor, though, we should point out. Zipp is owned by Sram, which has its own vast Taiwanese factory, and so it has been able to replicate its US carbon manufacturing processes precisely, and maintain completely control, but still benefit from the associated reduction in costs.
That is the main reason why, for the first time ever, you can own a set of Zipp carbon wheels for under £1,000: £985 to be exact.
The Zipp 303 S, the brand says, is a new wheelset that brings proven rim technology, and a host of new features to boot, down to a more affordable price point. Price, and what constitutes affordable, is of course somewhat subjective, but £985 is territory that Zipp has never entered into before.
Zipp currently has a more ‘budget’ focussed wheelset in its range – the 302 – but this still costs the best part of £1,400 and isn’t overly light, at a few grams shy of 1,700g.
So, despite now being part of the 303 product family, it’s really the 302 wheelset this new 303 S replaces.
That might sound a bit confusing, but it’s because previously Zipp decided to steer clear of including an entry level product into the 303 range. This new wheel, though, Zipp clearly believes is worthy of the name.
The 303 S weighs in at a claimed 1540g – that’s 155g lighter than outgoing 302 and amazingly only a miniscule 10g heavier than the Zipp 303 NSW Disc, the current cream of its crop.
So, despite its lower price tag the 303 S is actually one of Zipp’s lightest wheels. Weight, though, is only one factor in what makes a good wheelset.
As mentioned already the rim is a 45mm profile, but the rim depth is not so much of a buzz word these days as its width.
Wider profile rims have proven (by many brands, not just Zipp) aero benefits in terms of not just speed but crosswind stability, but crucially, and above all else, hugely influence the way tyres perform and especially how the tyres and rims can function more optimally together as a system.
The 303 S then has a 27mm external profile, but of greater significance is the broad 23mm internal width. Those measurements being so close, is only possible as Zipp has done away with the traditional rim hook (more on that in a bit) but these rim dimensions bring this wheel heaps of versatility.
The rim shape has been designed to optimise the performance of 28mm tyres and as such 25mm is the stated minimum size that is compatible.
The concept is that a 28mm tyre will assume a shape where its sidewalls are spread further apart, more parallel and upright (think like an inverted U), offering more structural support for the tyre carcass, whilst subsequently increasing the air volume inside, vastly improving potential for comfort gains and also reducing the chance of pinch punctures, while categorically not affecting rolling efficiency.
It should be noted, that as the 303 S use hookless rims they are tubeless only, as without the support of a tubeless tyre’s stiffer bead there would be a high risk of a standard clincher tyre blowing off. However, just to be clear, an inner tube can still be used inside a tubeless tyre if needed, for instance for a repair.
‘Road bikes are now expected to be far more versatile than ever before’, says Zipp’s wheel product manager, Bastien Donzé. ‘We had this in mind when we designed the 303 S.
‘For the past 30 years Zipp has very much focussed on increasing rider’s speed in terms of shaving off aero drag, but now we are looking at more ways in which we can help a rider to be fast’, Donzé continues.
‘We believe now we are finding ways that we can make significant gains in speed for every type of rider out there. A big part of that is down to rim widths and how they affect the tyre performance.’
Aero hasn’t been ignored. Far from it. The wide hookless rims on the 303 S actually create more of a seamless transition from the tyres to the rim surface, which is a component of reducing drag.
But the bigger deal about the new rim profile, Donzé urges, is to learn that it enables significantly lower tyre pressures to be used than ever before, and that, he believes, is the biggest untapped area in bicycle performance right now, with gains poentially bigger than aero and weight combined.
*Recommendations are a starting point for riders to begin tuning their optimum tyre pressure. Pressure suggestions at axs.sram.com/tirepressureguide
So to cut to it…for a 75kg rider using a 28mm tyre (tubeless only, as previously stated) that means, according to Zipp, a recommended front tyre pressure of 56psi and rear tyre at 60psi. Even for a 100kg rider the recommendations are still a very cushy 61/66psi.
What’s more the stated maximum recommended tyre pressure (printed on the rim) is a paltry 73psi.
‘Those tyre pressure recommendations will be hard to believe’, says Donzé. ‘We know we are asking a lot for riders to consider almost half the pressure that we know a lot of them still pump up their tyres to, but we have done exhaustive testing in the lab, and in the real world and we know there are big gains to be had, for every level of rider.’
‘It all comes down to how the tyres can work so much more effectively as a suspension system to isolate the rider from so much more of the road vibrations, and this, we now know, can bring big gains for power production and rider efficiency.
‘The maximum 73psi is really to try and get people to understand that any higher will simply ruin the ride experience on this wheelset. It is not directed at safety. We have tested to a higher degree, of course, but to go higher would be to lose all the benefits of this new design.’
At this stage Zipp makes no specific claims in terms of quoting actual numbers, beyond stating; ‘significant watt savings’, for the improvements it speaks of. We’d guess that’s a combination of testing still perhaps ongoing but also that the number of individual variables are potentially so great it’s hard to say with any precision for every rider set-up.
Regardless, there’s a huge amount to take in for a new wheelset, and we’d wager those low pressures will be a big talking point for sure. Also this will likely be the start of another wave of wheel development. It’s not like Zipp’s trends have never been followed before, and we can likely expect to see this new thinking gather more and more momentum, not to mention Zipp potentially rolling out these suggested benefits to other wheels within its own stable in due course too.
For my own opinions and thoughts on the 303 S after my initial testing, kepp your eyes peeled see my first ride review.
The Zipp 303 S will be available as 700c only, Zipp eschewing the trend to also offer the smaller diameter 650b option. However the 303 S will take up to a maximum 50mm gravel tyre width, although there are very few frames that will currently facilitate such a wide 700c tyre.
The 303 S wheels do not have any of Zipp’s trademark dimples – of course there has to be some concessions over the top of the line wheelsets – but instead there is a classy looking matt, UD carbon fibre finish.
As we recently saw with Zipp’s new Service Course products and G40 gravel tyres, it has updated its logo. That has been incorporated onto these 303 S wheels in a different way, now wrapping around the rim, in a more arty fashion.
That new graphic may be divisive for some, as the Zipp name, which many would be proud to display on their bikes, is much less visible than its previous rims, but that’s a small niggle really. A plus point, though, the new logos are printed on, not stuck vinyl graphics, which will give them improved longevity.
At the centre of it all are the same hubs as used on Zipp’s far pricier Firecrest wheelsets. The 76/176 DB hubs, have centre lock disc rotor mounting, and finally now too a lock ring is included! Hallelujah.
The hubs, Zipp says, have improved seal quality, reacting to feedback that its bearings needed to perform better in countries where it rains more than just a few days a year (we can’t all live in California, so thanks Zipp).
The wheels come with either XDR driver body for 12 speed Sram compatibility or with the standard 10/11 speed Sram/Shimano cassette freehub body. There’s no word on Campagnolo compatibility at this time.
The wheels come as standard set up as 12×100 front and 12×142 rear thru-axle as this has rapidly become the go to standard. But all axle configurations are catered for with simple end cap swaps (not included).
The wheels can be purchased individually, priced at £470 (front) and £515 (rear), and will be available in stores in May.
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World news – GB – Zipp 303 S: Versatility and speed for under £1,000