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Distinctive SawTooth rim is designed to reduce drag and increase stability

Zipp has revealed a new 454 NSW carbon clincher – featuring a distinctive ‘SawTooth’ rim shape – that it claims is its highest performing wheelset ever. 

The key innovation here is the SawTooth rim architecture (a little confusing because Zipp already has ABLC SawTooth Technology that refers to a specific dimple configuration) that’s intended to reduce aerodynamic drag and side force.

WH_454_NSW_CC_V1_700SR_11S_side.jpg

WH_454_NSW_CC_V1_700SR_11S_side.jpg

“SawTooth accomplishes this with a series of patented fin-shaped HyperFoil nodes along the inner diameter of the rim that work together with our new HexFin ABLC dimples for improved airflow,” says Zipp.

That’s quite a lot of jargon already. We’ll come back to it in a sec!

“The result is Zipp’s highest performing wheelset ever realised with both aero-drag reduction and reduced side force at all wind yaw angles. This is important because higher wind yaw angles are where bike handling is most affected by the wind.”

Although clearly related to drag and stability, Zipp doesn’t say exactly how it has concluded that the 454 NSW is the ’highest performing wheelset’ in the range.

WH_454_NSW_CC_V1_700SR_11S_detail2_Hyperfoil.jpg

WH_454_NSW_CC_V1_700SR_11S_detail2_Hyperfoil.jpg

So, those terms: HyperFoil is the name Zipp gives to the individual nodes on the rim – each individual 'tooth' that's 53mm deep at the bottom and 58mm at the tip. 

HexFin ABLC dimples are the hexagonally shaped depressions on each Hyperfoil.

“The angular shape of each dimple increases boundary layer mixing to help keep airflow attached to the rim for reduced aerodynamic drag and improved stability in crosswinds,” says Zipp.

“To further improve the effectiveness of the hexagonal dimples, they are arranged in fin-shaped clusters made up of variable sized dimples that work in concert with each Hyperfoil of a SawTooth rim.”

WH_454_NSW_CC_V1_700SR_11S_detail_Hyperfoil.jpg

WH_454_NSW_CC_V1_700SR_11S_detail_Hyperfoil.jpg

Crikey, I hope you’re keeping up! Ready for a bit more detail?

“The HyperFoils and HexFin ABLC dimples help to stabilise handling in gusting wind by increasing wind vortex shedding frequency. Lower frequency shedding produces larger, more powerful vortices. 

“In cycling terms, this unstable situation is often referred to as ‘buffeting’. The higher frequency vortex shedding produced by SawTooth creates a greater number of smaller, less powerful, yet more predictable vortices leading to greater wheel stability.”

The idea is that this increases your control and saves energy, leading to faster riding.

Check out our complete guide to Zipp wheels here.

Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins. No, really. This led to the testing of 36 distinct rim shapes and prototypes with different depths and numbers of HyperFoils.

The 454 NSW features Zipp’s existing Showstopper brake track – a moulded in texture with silicon carbide particles suspended in the surface resin – designed to enhance braking performance, particularly in wet conditions, and ImPress graphics which are printed directly on to the wheels so as not to compromise the effects of the dimples.   

Like Zipp’s other NSW wheels, the 454 uses the brand’s Cognition hubset. This features its Axial Clutch that uses magnets rather than springs to move and engage the ratchet rings in the freehub, the idea being to reduce friction when coasting. 

WH_454_NSW_CC_V1_700F_detail_hero.jpg

WH_454_NSW_CC_V1_700F_detail_hero.jpg

The wheels are built with Sapim CX-Ray spokes, 18 at the front, 24 at the rear.

The brake track width is 26.4mm and the maximum rim width is 27.8mm.

Zipp claims wheel weights of 690g (front) and 835g (rear), a total of 1,525g.

The front wheel is priced £1,550 and the rear is £1,950, a total of £3,500. You don’t need us to point out that that’s a helluva large price tag. ​ The Zipp 202 NSW wheels that have just arrived at road.cc for review are £2,369.

Each wheel includes a skewer, rim tape, inner tube, brake pads, valve extender and wheel bag.

www.zipp.com

 

 

Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight 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.

21 comments

Avatar
tritecommentbot [2268 posts] 1 year ago
1 like

Immense. Look just blows me away, so aggressive.

 

Guess we're at a bottleneck where a couple of watts savings per generation is the best you can hope for, until the next tech leap. 

 

Will hold out for Chinese versions in 2018 

Avatar
Jackson [381 posts] 1 year ago
5 likes

Lost it at "Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins"

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handlebarcam [1061 posts] 1 year ago
1 like

These will come in handy when the Paris Agreement on Climate Change means Batman has to convert his Batcycle to pedal power. Not sure the kevlar-reinforced pads on his Batbibshorts won't chafe though.

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Leviathan [2864 posts] 1 year ago
0 likes

Saw these on GCN  (no road.cc channel?) I will volunteer to test these for the next couple of years for anyone.

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joules1975 [484 posts] 1 year ago
0 likes

So are we heading towards a point where rims a directional?

The number of times I see people with tyres the wrong way round, I can see the benefits of such a rim design being completely undone by dim MAMILs putting the front wheel on the wrong way round.

I love the fact the design is different from an engineering perspective, but not sure on looks. Given that I'm never going to be able to justify Zipp wheels, I guess it doesn't matter.

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fukawitribe [2039 posts] 1 year ago
0 likes
joules1975 wrote:

So are we heading towards a point where rims a directional?

The number of times I see people with tyres the wrong way round, I can see the benefits of such a rim design being completely undone by dim MAMILs putting the front wheel on the wrong way round.

We'll have to insist they get the disc brake version then. Even then..

Avatar
Zebulebu [78 posts] 1 year ago
2 likes
joules1975 wrote:

So are we heading towards a point where rims a directional?

The number of times I see people with tyres the wrong way round, I can see the benefits of such a rim design being completely undone by dim MAMILs putting the front wheel on the wrong way round.

I love the fact the design is different from an engineering perspective, but not sure on looks. Given that I'm never going to be able to justify Zipp wheels, I guess it doesn't matter.

There's no such thing as 'the wrong way round' for a road tyre. Tread patterns on road tyres are nothing more than marketing gimmicks. The fatter the tyre, the more tread makes a difference, of course -and if you're riding shitty surfaces or offroad, then slicks perform worse - but on most 'road' bikes (which is what MAMILs tend to ride) there is lterally zero difference between a tread facing the 'right' way and facing the 'wrong' way

Avatar
brooksby [2694 posts] 1 year ago
0 likes
Zebulebu wrote:
joules1975 wrote:

...

The number of times I see people with tyres the wrong way round, I can see the benefits of such a rim design being completely undone by dim MAMILs putting the front wheel on the wrong way round.

...

There's no such thing as 'the wrong way round' for a road tyre. Tread patterns on road tyres are nothing more than marketing gimmicks. The fatter the tyre, the more tread makes a difference, of course -and if you're riding shitty surfaces or offroad, then slicks perform worse - but on most 'road' bikes (which is what MAMILs tend to ride) there is lterally zero difference between a tread facing the 'right' way and facing the 'wrong' way

Really?  I was always told that the tread pattern *did* make a difference.  Actually took off a Marathon Plus when I realised the chevrons were pointing the wrong direction (and taking a Marathon Plus off a wheel and putting it back on again really isn't something you do for fun yes ).

Avatar
Bobbinogs [254 posts] 1 year ago
0 likes

Yepp, what he says ^^.  When you look at 'directional' tyres like Conti GPS4000s2 it is a bit of joke to think that the 'tread' can make any diference in either direction.

 

I sometimes think that a lot of this comes down to smugness and the delight of being 'in the know', bit like when some folks smirk about a front wheel being on the 'wrong' way when the QR skewer ends up on the RHS and yet it is only the 'wrong' side because pros traditionally stop on the RHS and therefore it is easier for the service teams to get the wheel off if the QR is on the left.  Unfortunately, I get to change my own tyres/wheels...

Avatar
brooksby [2694 posts] 1 year ago
1 like
Bobbinogs wrote:

... bit like when some folks smirk about a front wheel being on the 'wrong' way when the QR skewer ends up on the RHS and yet it is only the 'wrong' side because pros traditionally stop on the RHS and therefore it is easier for the service teams to get the wheel off if the QR is on the left.  Unfortunately, I get to change my own tyres/wheels...

I'd wondered about that.  I was chatting with the bloke in my LBS last night - after I bought some security skewers to replace my QR skewers - and he demonstrated taking a skewer out and said it really doesn't matter which side the lever goes on, but most people put them on the LHS.  I'd assumed that there was an actual *reason* for the QR lever going on the left...

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drosco [415 posts] 1 year ago
2 likes

Am I the only person who thinks they look a bit daft?

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StraelGuy [1095 posts] 1 year ago
6 likes

Brooksby, I've always looked at it as a congestion thing. There's plenty going on on the right side of the rear wheel so I have the lever on the non-drive side. Of course, you then put the front lever on the same side for feng shui reasons yes.

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fukawitribe [2039 posts] 1 year ago
0 likes
Jackson wrote:

Lost it at "Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins"

Too much science ? Here's more (few years old now)..

Quote:

Experimental analysis of finite wing models has demonstrated that the presence of tubercles produces a delay in the angle of attack until stall, thereby increasing maximum lift and decreasing drag. Possible fluid-dynamic mechanisms for improved performance include delay of stall through generation of a vortex and modification of the boundary layer, and increase in effective span by reduction of both spanwise flow and strength of the tip vortex. The tubercles provide a bio-inspired design that has commercial viability for wing-like structures. 

http://icb.oxfordjournals.org/content/51/1/203.full

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brooksby [2694 posts] 1 year ago
0 likes
guyrwood wrote:

Brooksby, I've always looked at it as a congestion thing. There's plenty going on on the right side of the rear wheel so I have the lever on the non-drive side. Of course, you then put the front lever on the same side for feng shui reasons yes.

Well, yes, that was my logic too. 

(There's probably a Rule about it, isn't there...)

Avatar
Richard1982 [78 posts] 1 year ago
1 like

"Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins"

FACT.

 

 

I certainly don't think they were inspired by this design from a few years back, if that's what you're thinking.

http://www.nottinghampost.com/dimitris-reinvents-wheel-bike-riders-edge/...

Avatar
pwake [428 posts] 1 year ago
1 like
Jackson wrote:

Lost it at "Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins"

It's called Biomimicry and has resulted in some excellent engineering products, because Mother Nature/natural selection has resulted in designs that we are only now beginning to understand and copy. A couple of good examples being, velcro (inspired by burrs) and winglets (inspired by the shape taken by birds wings). Stay curious my friend...

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brooksby [2694 posts] 1 year ago
1 like

I knew fish couldn't ride bicycles, but now I find that humpback whales *can*, or something...

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Jackson [381 posts] 1 year ago
0 likes
pwake wrote:
Jackson wrote:

Lost it at "Zipp says that the inspiration for the SawTooth design came from the irregular shape of the leading edge of humpback whale pectoral fins"

It's called Biomimicry and has resulted in some excellent engineering products, because Mother Nature/natural selection has resulted in designs that we are only now beginning to understand and copy. A couple of good examples being, velcro (inspired by burrs) and winglets (inspired by the shape taken by birds wings). Stay curious my friend...

"Lose it" = "to start laughing" at something Spinal Tap would've said if they were designing bike wheels. Not saying it's an invalid design. 

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willythepimp [116 posts] 1 year ago
0 likes

Blatant rip off from the above link.

I was going to saythat they have finally reinvented the wheel, but it appears that they didn't.

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Swiss [64 posts] 1 year ago
0 likes

It would be more exciting if they were inspired by t-rex's or crocodile tails. Humpback whales seem a bit pedestrian.

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CXR94Di2 [1856 posts] 1 year ago
0 likes

It will be nice when a reasonable priced version appears on the market