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New model offers a performance advantage over the world’s best aero wheel, according to Swiss Side

Swiss Side’s new Hadron 625 aero clincher wheels, which the brand claims to offer a 1% performance improvement over ‘the world’s best aero wheel’, will be available to pre-order in a fortnight.

Swiss Side say that the results from their wind tunnel testing have been “unreal”, and claim that the Hadron 635 outperforms the ‘world’s best deep profile aero wheel’. Swiss Side don’t name this wheel, but they say it’s from a ‘big brand’ and it’s 82mm deep, so we assume (dangerous, we know) they’re talking about the Zipp 808.

Of course, these claims are based on Swiss Side’s own tests (see how the wheels were tested on Swiss Side’s website), and other brands would doubtless dispute the findings. We’re reporting the claims here, not corroborating them.

Swiss Side says that the 62.5mm-deep Hadron produces slightly more drag than this 82mm-deep reference wheel but that the overall performance, according to its own criteria, is better.

“For a slight 1.1% increase in drag, the Hadron offers 5.9% reduction in side force, combined with a delayed stall characteristic and improved high cross-wind angle performance,” says Swiss Side. “These characteristics in particular also offer benefits at low riding speed because for a given wind speed, the effective cross-wind angle is higher. Based on an aerodynamic efficiency performance function which gives a 70% weighting to drag and a 30% weighting to side force, the Swiss Side Hadron offers a 1% performance improvement over the world’s best aero wheel.”

So, the 82mm-deep wheel offers slightly better aerodynamics but the Hadron 625 is better overall, according to Swiss Side. As mentioned, the testing was done according to Swiss Side’s criteria and that 70% / 30% weighting to the findings is Swiss Side’s own rather than an industry standard.

Check out Swiss Side’s website to see exactly how the wheels were tested in the wind tunnel – everyone does it differently – and how those conclusions were reached. The brand says that it tested the front wheel only, then both wheels on a complete bike frame, then both wheels on a complete bike with a dynamic leg dummy. The published results relate just to the ‘front wheel only’ tests although Swiss Side says, “The relative wheel performance offsets and characteristics are the same as with the complete bike simulation methods.”

The Hadron 625 uses an aluminium/carbon rim that’s 27mm wide and a toroidal profile (the side walls are curved). The braking surfaces (23mm width) are aluminium. The hubs are forged and machined 6061 T6 aluminium with sealed bearings (ceramic bearings are available as an option) while the spokes are straight-pull Sapim CX-Rays, 18 radially laced at the front, 24 two-cross at the back. The wheels ship with a Shimano/SRAM 8-11-speed cassette body although Camagnolo cassette bodies are available on request.

Swiss Side say that the wheels weigh 740g (f) and 916g (r) – a total of 1,656g, not including QR skewers or rim tape.

The Hadron 625 wheelset is priced at €799 for EU customers, including VAT and shipping. That’s about £662 at the moment. They cost €665.83 outside the EU, exclusive of VAT and shipping. Those prices include skewers, rim tape and replacement spokes. If you want ceramic bearings, they’ll cost you an additional €125 (around £104).

You can pre-order at www.swissside.com from 15 April, with orders expected to ship at the end of June.

Mat has worked for loads of bike magazines over the past 20 years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for seven years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.

13 comments

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AyBee [85 posts] 2 years ago
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How can you compare a 62.5mm with a 82mm fairly? Apples and pears assuming you're testing both straight ahead and cross winds.

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BikeBud [244 posts] 2 years ago
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Results from tests have been "unreal". Hmmmm. Does that mean "not real"?

Decent price, but there's more to wheels than Price and marketing spiel.

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merckxissimo [57 posts] 2 years ago
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merckxissimo [57 posts] 2 years ago
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That was meant to be a reply to AyBee. Technology never was my strong point.

Interesting product - great write up. I called you out before on reporting aerodynamic claims Mat; I can certainly see here how hard it is to convey the story whilst remaining nonpartisan.

The wheels sound like a similar story to the Flo Cycling offerings, of which I have 60mm and 90mm variants both of which have been deeply (geddit?) impressive. Not the lightest wheels on Earth but once they're up to speed they don't hold you back at all, and with 'proper' brake track to boot  3

Good to see they also publish plenty of data too. They certainly pick their claims carefully... next we will have "The most aero wheel between 14 and 15 degrees of yaw". Notwithstanding, given the price most would be more than content for them to claim "almost as fast as an 808 but a bit cheaper and heavier". Interesting to see more companies in the market though. With the likes of Boyd, Flo, SwissSide and others offering wheels at <50% of the cost of Zipp and <75% of the cost of HED, the pressure is on the big boys to keep developing!

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Mat Brett [630 posts] 2 years ago
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As mentioned above, we're reporting the claims of the brand rather than corroborating them... the same as every other time we report a brand's aero claims.

You can be persuaded by the stats or not believe them, as you see fit. It's always the same deal.

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Metjas [362 posts] 2 years ago
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I needed a second careful look at the model name on that 2nd picture, as I initially thought there was an additional subliminal message about a certain wheel parameter  3

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SamShaw [266 posts] 2 years ago
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merckxissimo wrote:

With the likes of Boyd, Flo, SwissSide and others offering wheels at <50% of the cost of Zipp and <75% of the cost of HED, the pressure is on the big boys to keep developing!

It'll be interesting to see if there's any change in offering from the established brands. SwissSide have clearly priced these at a point that is (sort of) achievable. £6-700 for a pair of bling wheels, not out of the realms of reality... £2,000+ on a set of wheels... that's going to make you think a bit.

Wonder if SwissSide are going to try and put their product into the professional ranks too.

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fukawitribe [1957 posts] 2 years ago
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AyBee wrote:

How can you compare a 62.5mm with a 82mm fairly? Apples and pears assuming you're testing both straight ahead and cross winds.

Quite easily (or at least, conceptually not difficult). For details, why not pop over the SwissSide website and have a butchers at the Hadron project page

http://www.swissside.com/hadron

..there's load of information about the wheel, test methodology, results etc there. Interesting.

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davecochrane [142 posts] 2 years ago
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If I could have a set of wheels that compare favourably with 808s, with alu brake tracks and decent hubs, then I'm buying that set of wheels. If the claims can be backed up, Zipp are about to have to slash their pricing by a pretty brutal amount. Perhaps a similar adjustment to wheels is coming that was seen in power meter pricing last year....and not before time.

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pwake [395 posts] 2 years ago
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davecochrane wrote:

If I could have a set of wheels that compare favourably with 808s, with alu brake tracks and decent hubs, then I'm buying that set of wheels. If the claims can be backed up, Zipp are about to have to slash their pricing by a pretty brutal amount. Perhaps a similar adjustment to wheels is coming that was seen in power meter pricing last year....and not before time.

I wouldn't hold out for a brutal price cut from Zipp anytime soon though. By far their major market is North America, Zipps are still made in Indianapolis and US consumers will pay a premium for a "Made in the USA" product. On top of that they are also an aspirational product from the market leader and, if it matters, they always massively outnumber any other brand in the Kona wheel count (shows who's buying).
Although it was undoubtedly a big decision, I took the plunge and bought a pair of 404 tubulars about four years ago; never regretted that decision and I think I actually got value for money, as they are a pleasure to use and top-notch quality.

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JeevesBath [180 posts] 2 years ago
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BikeBud wrote:

Decent price, but there's more to wheels than Price and marketing spiel.

Hmm, a pair of these would cost more than all three of my bikes cost me combined  2

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harman_mogul [244 posts] 2 years ago
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Metjas wrote:

I needed a second careful look at the model name on that 2nd picture, as I initially thought there was an additional subliminal message about a certain wheel parameter  3

Wink wink! And 'Hadron' is not the only questionable feature about the brand and model name....let's hope the wheel is not a 'Collider'!

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fukawitribe [1957 posts] 2 years ago
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JeevesBath wrote:
BikeBud wrote:

Decent price, but there's more to wheels than Price and marketing spiel.

Hmm, a pair of these would cost more than all three of my bikes cost me combined  2

Fair enough - but I suspect that their market may not be those people who spend about 200 quid on a bike.