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Cannondale SystemSix review

14 Mar 2019

A slick looking silhouette backed up by equally slick performance; the System Six offers a bit of everything, but mostly a lot of speed

Cyclist Rating: 
Exciting to ride and undeniably fast • Handling feels more road-bike and less full aero • Wheels are superb • Well thought out bar/stem combo
A modicum more comfort would be the icing on the cake

Intriguingly, Cannondale hasn’t produced an aero road bike since the days when its top-end race frames were made from aluminium.

While all the other big brands have been busy refining tube shapes to shave off wind drag, Cannondale has defiantly stuck by its traditional-looking SuperSix Evo.

Until now.

Biding its time, though, has allowed the company to keep track of developments during years of rapid advancement in aerodynamics, especially since the arrival of disc brakes.

And with the SystemSix it clearly believes it has entered the market right at the top, declaring it to be nothing less than the fastest road bike in the world.

The brains

The man making this bold claim is Australian aerospace engineer Nathan Barry.

When I attended the SystemSix’s launch in Girona earlier this year, Barry urged me to think of it not as an aero road bike but as a faster road bike.

The point he was trying to make was that the SystemSix should have a broader appeal than just for those who race.

‘The notion you have to already be going fast to benefit from aero gains is a fallacy,’ Barry said.

‘Even at 15kmh, 50% of the overall resistance we experience is down to aero drag.’

More intriguing were his claims that the new SystemSix would be as fast or faster than a standard road bike (Cannondale used the SuperSix Evo as the benchmark) on climbs up to 6% gradient.

He also claimed it would only lose out by around 20-30 seconds up Alpe d’Huez, despite the extra weight.

Faster in sprints, faster on descents, faster on lone attacks… the data rolled on.

And what about against its rivals, the likes of Specialized’s Venge and Trek’s Madone?

You’ve guessed it: faster, says Barry. I was eager to take the SystemSix out of the context of graphs and spreadsheets to see if it would live up to the hype out on the road.

Playground of the pros

I started testing the bike while still in Girona, on roads and climbs frequented by the numerous pros who live there – a perfect location to get to grips with a machine Cannondale will be banking on to win at least a few WorldTour races next season.

It didn’t take many kilometres of hammering through Girona’s rolling countryside and up infamous climbs such as the Rocacorba before I realised Cannondale was not making hollow promises for the SystemSix.

The sensation of speed was immediate.

When sprinting, the bike was explosive, but not in a bullish, clumsy way as with some rigid aero machines.

The SystemSix conveyed an unexpectedly nimble persona. There was a deftness about the way it handled that felt much more like a standard road bike than its aero silhouette suggests.

It felt light-footed beneath me as I cranked hard uphill, yet also stable and accurate through switchbacks on the way back down.

There was one thing that took some getting used to, though – the visual effect created by the tyre and rim combination.

Looking down at the wheels, the wide Knot 64 carbon rims (32mm at their most bulbous point) sit visibly proud of the 23mm Vittoria Rubino Pro Speed tyres.

I found it unusual to the point of being unnerving.

A few things need explaining here.

For starters Cannondale is not backtracking to skinny tyres.

Nor has it fitted Vittoria’s mid-range Rubino tyres instead of top-end Corsas to save a buck.

The reason it has gone with 23mm tyres is that they actually measure 26mm when paired with the 21mm rim beds, which Barry’s testing concluded was fastest.

It’s the same deal for the Rubino.

Quite simply it tested fastest, so that was that.

The thinking harks back to a patented aero principle that Cannondale licensed from the late wheel guru Steve Hed.

Skipping the technical details, it relates to the tangent angle between the rim edge and the tyre.

The theory is that when the tyre is narrower than the rim, the air will stay better attached as yaw (wind angle) increases, creating a narrower wake, less drag, more speed and greater stability.

And it works.

Aside from the slightly kooky aesthetic, this is undoubtedly one of the best tyre/wheel combos I’ve tested, and definitely brings substantial benefits to the bike as a whole.

What’s interesting is that it’s thanks to disc brakes that the rim can be so wide.

Early speculation was that disc brakes would only ever hinder aero performance, but here is Cannondale demonstrating that discs can actually make a bike faster.

Staying with the Knot components, the bar/stem is also a real success.

Neatly hiding away all the cabling is one positive aspect, but more important is that it’s actually a two-piece setup, meaning positional tweaks can be made and bars and stems can be individually swapped to suit a rider’s fit preferences.

Home turf

Since leaving the sunshine and near-perfect roads of Girona, I have also had plenty of time to put the SystemSix through its paces on my more rutted local lanes in some much grimmer conditions, and my feelings about the bike haven’t altered.

It continues to impress.

It’s undeniably fast and extremely efficient, and if it lacks anything, it’s that old chestnut: comfort.

Aero bikes have been steadily improving in this regard. All the most recent iterations I’ve tested have been noticeably better than their predecessors, the Madone in particular.

Obviously the SystemSix has no direct predecessor, but it’s certainly not the harshest out there.

That said, it could benefit from a touch more cushioning, and it would be easy to gain some comfort back by swapping to wider, tubeless tyres, for which there is plenty of clearance.

Of course, that would spoil Barry’s optimal tyre/rim interface, leading to the loss of a tiny amount of speed, but if you’re not too bothered about saving every second then it would achieve a more friendly ride feel.

Cannondale has certainly entered the aero road sector with a bang.

I’m not going to say whether I think it’s the fastest bike out there.

I’ve tested the latest Venge and Madone and without a side-by-side test in lab conditions I couldn’t be sure which is truly fastest.

One thing I will say, though, is if I was going to buy a SystemSix, it might not be this one.

The Ultegra Di2 version has the same frame, the same Knot 64 wheels and the same bar/stem, but at a massive £2,000 cheaper.

Just saying.

Rating - 4/5


Frame Cannondale SystemSix Hi-Mod Dura-Ace Di2
Groupset Shimano Dura-Ace Di2
Brakes Shimano Dura-Ace Di2
Chainset Shimano Dura-Ace Di2
Cassette Shimano Dura-Ace Di2
Bars Knot System
Stem Knot System
Seatpost SystemSix  
Saddle Prologo Dimension Nack
Wheels Knot 64 carbon, Vittoria Rubino Pro Speed 23mm tyres
Weight 7.69kg (56cm) 

This article was originally published in issue 83 of Cyclist magazine


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