Cannondale Synapse Carbon 3 Ultegra road bike

Combining a smooth ride with the stiffness and performance of a race bike, the revamped Cannondale Synapse impresses.

Cannondale's revamped Synapse offers much of the performance of a race bike but with added comfort, both from geometry that is more relaxed and a frame designed to absorb vibrations and deflect impacts. This £2,499 Carbon 3 Ultegra model sits in the middle of a six-bike range and is to all intents and purposes the same bike Peter Sagan raced successfully earlier this season.

The revamped Synapse is Cannondale's comfort alternative to their racier SuperSix Evo. Cannondale has made changes that focus on smoothing out rough roads without compromising on the stiffness and performance that a cyclist who likes to combine speed with distance savours. If you like to ride fast, but never race, then a bike like the new Synapse, combining the performance of a race bike with added comfort is a smart choice.

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Ride: Fast yet comfortable

Cannondale pack the Synapse with what they call micro suspension features, including a skinny 25.4mm seatpost, sculpted stays and shock-damping carbon layup in a smart looking frame. These three key features combine to absorb the impacts that can lead to a choppy and bumpy ride on anything but a billiard smooth road surface.

With such roads in short supply in my local area, the Synapse has hugely impressed. Take it along any less-than-perfect road surface, even chuck it along a bridleway or roughened track, and the Synapse noticeably filters out the harshness.

We're not talking plush, mountain bike-style suspension here though. The Synapse is still a firm ride - it's a carbon road bike on 25mm tyres after all - but it's noticeably smoother than a regular carbon road bike.

In achieving the comfort, which is really quite impressive for a carbon bike, Cannondale haven't sacrificed performance or stiffness. There's plenty of gusto when you stamp on the pedals, whether slinging it up the hills or sprinting along flat roads, the frame and fork reveal a tautness that puts some race bikes to shame.

The handling is a highlight. It's not quite as aggressive as the SuperSix Evo, the head tube is 2.5cm taller at 18cm, but in the drops you can get nice and low and crack on in an aerodynamic position. Typically we might expect to also find a shorter top tube, but Cannondale have kept the reach similar to the Evo with a 56.1cm horizontal top tube measurement.

Cannondale fitted the test bike with a whole bunch of spacers which is fair enough, but the tall headset top cap made it difficult to achieve my desired position. Shuffling the spacers above the stem and swapping the top cap for one borrowed from an Evo had the bars at a preferred height. For me, the head tube is generous enough without piling on the tall headset cap.

One area where the Synapse really shone is in its general handling in a wide range of situations. The 100cm wheelbase, longer than a race bike's, gave the Synapse great stability at all speeds. That, combined with the frame's ability to squash high frequency vibrations lends the Synapse fantastic smoothness and fluidity when descending fast and bumpy downhills. It's not just comfort that the frame['s features provide, but increased control at speed, which is appreciable on descents with anything but a silky smooth Tarmac surface.

I came away impressed with Cannondale's redesigned Synapse. It admirably juggles the demands of performance and comfort without compromise, producing a ride that is rewarding for riders of all levels. You could race it, ride it in sportives or just ride to the coffee shop on Sunday mornings. It's a very capable endurance road bike.

Through fast descents, slow corners, up the climbs and along flat roads, the bike feels fast, fluid and comfortable. It's a lot of fun to chuck the bike around with a bit of aggression when in the pursuit of a high average speed say, but equally when you're cruising along the Synapse feels settled and unflappable.

Frame: The comfort factor

The reason the Synapse is so inspiring and comfortable to ride is the dramatically redesigned frame. The model has been in Cannondale's range for a number of years, but this year received a ground up redesign that evolves some previous technologies.

Further developed is SAVE+ (Synapse Active Vibration Elimination) technology. This comprises three complementary micro suspension systems; smaller road chatter is handled by the carbon layup, bigger hits by the design and shape of the fork and stays, and the really big stuff by the seatpost and seat tube.

The twisted helix seat stays increase the length of the fibres – they're actually longer than the seat stays – so vibrations take longer to travel up the stays. The fork features offset dropouts to produce more rake to add compliance while still retaining the ride quality. This damps out more of the high frequency vibrations.

Critical to the design is that there are not one but three systems that contribute to the bike's desired bump-absorbing compliance. Cannondale don't give any figures on the amount of vertical deflection, but it's clear it works: the frame absorbs high speed frequency stuff and bigger impacts very well.

This is a bike you really can ride all day and finish feeling fresh. Even during some of my faster and more taxing routes the Synapse left me feeling less battered than I have felt on many other bikes.

The 25.4mm seatpost, the smallest diameter used by any of the main brands, is a key component in providing deflection on impact. You can sometimes see the nose of the saddle moving fore-and-aft when you're riding along. And by integrating the seatpost clamp into the frame, Cannondale have increased the amount of exposed post available to deflect. The saddle height is easily adjusted, there's a 4mm Allen bolt in the top tube, covered with a rubber bung.

The carbon layup is the final measure in absorbing vibration, and Cannondale have worked hard on it. With the seatpost taking out bigger impacts, the combination of the carbon layup and tube shapes damps high frequency vibrations, with the effect that road buzz is reduced noticeably.

Cannondale uses the same frame mould throughout the range. This is the first time the proprietary BallsiTec carbon, borrowed from the Evo, has been used for the Synapse. The top models get a higher quantity of ultra- and hi-mod carbon fibre, while the three cheaper bikes have more intermediate modulus carbon.

The resin in the BallisTec composite is designed to absorb the energy from impacts. The layup of the carbon fibre is also fundamental, with a staggered approach of overlapping layers that smooth the transition between tube junctions.

There is still a reasonable degree of feedback. You're not completely isolated from the road, but instead protected from a lot of the harsher stuff that can lead to a choppy and uncomfortable ride.

Compared to the hi-mod Synapse I rode at the launch there is an appreciable difference - the hi-mod is marginally smoother - but you're still getting the best bits of the new Synapse platform in this more affordable model. All frames will take up to 28mm tyres, with most specced with 25mm tyres as standard.

Cannondale didn't want to sacrifice stiffness in the pursuit of comfort. The 73mm wide BB30a bottom bracket allows for a wider downtube and fatter chainstays to be used. The Power Pyramid seat tube, one of the most intriguing design features I've seen on a road bike in a long time, allowed Cannondale to have a wide seat tube but removing the centre section reduces the weight without reducing stiffness. It's not like that for any aero or comfort reasons, in case you're wondering.

They also wanted the Synapse to be light, which at a claimed 950g for a 56cm frame, it certainly is. Even the modest build of this bike tips the scales at 7.8kg, which is a good weight for a bike of this money.

Build kit: Ultegra, FSA and Mavic mix

There are six models in the new Synapse range, starting at £1,699 for a Shimano 105 bike and rising to £6,999 for the Hi-Mod Black Inc with full Dura-Ace Di2. The frame looks the same across all the models, but the top three use a hi-mod carbon frame, the cheaper three a less expensive grade of carbon fibre.

The £2,499 Carbon Ultegra 3 bike here sits right in the middle of the range and is the most expensive of the regular non hi-mod frames. That price gets you a bike with Shimano's Ultegra 6800 11-speed groupset and an FSA SLK Light Carbon chainset as Shimano don't make a BB30 chainset.

It works fine though and doesn't negatively impact shifting, which is nothing but slick, crisp and rapid. The compact 50/34 chainset partners with a 11-32 cassette which gives a wide range of gears, low and high, for any cycling adventure. If you're planning to take on a hilly UK sportive or the Etape next year, this is a generous gearing that will see you to the top of any mountain.

Clearance for wide tyres is a huge bonus of the Synapse, and Mavic's own 25mm tyres are a good choice, fast and grippy. They're mounted to Mavic Aksium S wheels, a solid and stiff design with long-lasting bearings. You could easily go to 28mm tyres: there is space in the frame for them.

Finishing the bike is a Cannondale branded handlebar and stem, both made from alloy, and a carbon seatpost. The handlebar offered a nice ergo shape, comfortable in the hoods and on the tops, and equally so in the drops, which proved to have a shortish reach. I swapped the stem out for a slightly longer one, to suit my reach. The Fizik Aliante Delta saddle has a scooped shape that most will find plenty comfortable enough.

Conclus​ion

At 7.8kg (17.19lb) without pedals the Synapse is a competitive weight for the money. You don't pay much of a penalty at all for the comfort the bike offers, and a wheel upgrade and some carbon bits would have the weight much closer to 7kg, showing the good upgrade option of this model. The next model in the range is £3,299, with a full Ultegra groupset and the hi-mod version of the frame, so it's a bit of a leap.

Endurance road bikes is one of the hottest phrases in cycling right now, up there with disc brakes and aerodynamics. There are a couple of interesting contenders, established bikes like the Trek Domane, Specialized Roubaix and BMC GranFondo, along with newer bikes like the Bianchi Infinito CV, that compete in the same sector as the new Synapse. Against such competition the Synapse stands up well.

Its redesigned frame pitches the Synapse squarely at the performance cyclist who values ride comfort without wanting to sacrifice weight and stiffness; the bike delivers on those fronts too. It's a superb all-rounder really, happy going flat out up hills or wafting through the countryside from pub to cafe.

Unless you're racing and demand a really low front end, the Synapse is the better choice for most cyclists than the company's highly acclaimed SuperSix Evo. In fact, in updating the Synapse, Cannondale might have just produced a very good reason not to buy its flagship road bike.

Verdict

Super smooth and comfortable distance bike with rewarding handling and fast performance.