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Cannondale Synapse Carbon Ultegra review

11 Mar 2020

The Cannondale Synapse is a bike for all occasions in this modern world of mixed-terrain riding

Cyclist Rating: 
Comfortable • Suitable for mixed terrain • 'Affordable'
Doesn’t come with tubeless tyres

Reviewing the Cannondale Synapse made me realise something: gravel riding is in vogue, isn’t it? Over the last few years, it seems like we’ve all ditched lycra jerseys for cotton t-shirts, saddlebags for frame bags and inner tubes for sealant. It has boomed to such an extent that we here at Cyclist have even launched a magazine dedicated to it.

It has also meant that the discerning bike rider has been shopping around for a bike to go off-road. And while bike brands have been quick to develop gravel bikes, the consumer is yet to fully turn its back on tarmac, instead wanting something capable of performing on-road just as well as off it.

That’s where the Cannondale Synapse Carbon comes in. The American brand’s endurance model that has been subtlely changed year after year to fit the above bill. It has room for 32mm tyres, a comfortable carbon frame and tubeless-ready wheels. There are mounts for guards, a 1-to-1 gear ratio and even a tidy, outdoorsy green paint job.

When I found myself testing the Cannondale Synapse Carbon over the winter, I was confidently veering off the tarmac and onto the byways and gravel paths more often than not.

It made me think that the Synapse is now a gravel bike in all but name but do not be fooled, despite this versatility, it is yet to forget its roots in road.

Comfort and weight

Ultimately, the Synapse is still an endurance road bike, not a gravel bike, and therefore needs to function best on tarmac. Imperative to that is a frame that while light and nippy is fundamentally a solid base of comfort when riding considerable distances.

In the Synapse, Cannondale has designed a frame that does just that.

I recently ticked off my first 100km ride for quite some time. Honestly, I was dreading it, knowing my legs and form were not there. But thanks to the Synapse, the ride turned out to be quite bearable. In fact, ignoring my embarrassing time up Kidd’s Hill in West Sussex, the Synapse made it quite enjoyable.

Initially, I thought the comfortable feeling I got riding the Synapse was because of a relaxed geometry. Interestingly, the geometry charts for my 54cm frame suggest something on the racier end of the endurance spectrum.

Sure, the wheelbase was a little longer than usual and the stack height quite high but the fork rake suggested nothing too drastic.

Where the comfort likely came from was the details within the design of the frame and the finishing kit attached to it.

Cannondale has used BallisTec carbon for its Synapse frame. While I can only offer an opinion, mine was such that this technology offered just the right amount of flexibility in the seatstays and seatpost and stiffness in the bottom bracket to provide ample riding comfort without the sacrifice of handling and acceleration.

Buy now from Evans Cycles for £3,800

Then there’s Cannondale’s SAVE (Synapse Active Vibration Elimination) technology, the manipulation of tube shaping in specific areas with certain carbon layups that ultimately helps to reduce road shock via a micro-suspension system while remaining torsionally rigid.

In fact, on group rides, others could see the bike's SAVE technology in action, especially in the narrow 25.4mm seatpost, when I wrestled to stay on top of a gear.

Unlike some competitors in the endurance market, aerodynamics seem not to have been high on the agenda during frame design. This is not to say the bike is not fast but it does lack that ability to maintain momentum at the highest speeds.

Rolling along at 30kmh on the flat is far from a struggle on the Synapse and as for climbing, this bike punches above its weight, literally. 

The bike responds with vigour if you begin to stomp on the pedals on inclines and ticks along at a fair rate when you're rooted in the saddle. Again, I noticed that the comfort being offered up by the bike made those longer climbs more bearable which ultimately allowed me to push harder and climb faster.

As a complete bike with pedals, the Synapse tips the scales at 8.2kg, which is impressive considering the alloy wheelset and alloy finishing kit. Even more impressive is that it climbs like a bike that weighs closer to the 6kg mark.

Wheels and tyres

It is not just the makeup of the frame that has produced this comfortable feeling. As previously mentioned, you can fit 32mm tyres on this bike. Off the peg, I was provided with a set of 28mm tyres Vittoria Rubino Pro tyres firmly affixed to a set of alloy Fulcrum Racing 600 DB wheels.

With these wider tyres, I found myself running closer to 80psi, much comfier than the 95psi I ran on a set of Vittoria Rubinos in Cannondale’s lightweight SuperSix Evo race bike albeit probably marginally slower.

I am a big fan of Vittoria’s Rubino tyre and their use on this particular Cannondale Synapse although it came with a slight drawback, they are not tubeless-ready.

Fulcrum’s Racing 600 DB wheels are, and with tyre clearances up to 32mm, you’d think the Synapse is a bike primed for a wide tyred tubeless setup. Realistically, if I bought this bike, I’d be looking to immediately swap over to a set of wide tubeless tyres, say the Continental GP5000s in a 32mm width.

Firstly, it would be a way of really ensuring that comfort and puncture-protection and secondly, it would only open up the wider possibilities of off-road riding.


A bike is more than its frame and wheels, it's also components and the choice of components for this sub-£4,000 bike, Cannondale has done a stellar job.

The aforementioned Fulcrum wheels are neither the lightest nor most aero but are comfortable, robust and primed for a dabble in gravel riding (like the frame, I guess).

As is the groupset fitted, Shimano Ultegra Di2 Disc. Slightly heavier than Dura-Ace but just as responsive, just as efficient and cheaper to replace in the long run.

The bike also comes with an endurance gear ratio of 50/34 in the front and 11-34 in the back. I never found myself dropping down to that 1-1 gear ratio on tarmac but found it a godsend on steeper, gravel paths and I would likely find it the same if I used this bike for any bikepacking adventures. Just like the hidden mudguard mounts that are hidden in the bike’s seat stays.


At £3,799, to call the Cannondale Synapse Ultegra ‘affordable’ could be considered a misnomer as, after all, that is still an awful lot of money. Yet place it into the market and you realise it prices up better than most rivals.

A similar specced build of the Specialized Roubaix Comp Ultegra Di2 disc will set you back an extra £600 while a Trek Domane with Ultegra Di2 will cost you an extra £1,101, albeit with a set of Bontrager Aeolus carbon tubeless wheels.

So you could consider it competitively priced and if you do not, there’s always the full carbon Shimano 105 build that comes in at £2,199.99.

Buy now from Evans Cycles for £3,800


Frame Cannondale Synapse Carbon
Groupset Shimano Ultegra Di2 disc
Brakes Shimano Ultegra Di2 Disc
Chainset Cannondale 1, BB30a, FSA rings, 50/34
Cassette Shimano 105, 11-34
Bars Cannondale 2, 7050 Alloy, Compact
Stem Cannondale 2, 6061 Alloy, 31.8, 7°
Seatpost Cannondale 2, UD Carbon, 25.4 x 350mm
Saddle Fabric Scoop Shallow Sport, steel rails
Wheels Fulcrum Racing 600 DB, Vittoria Rubino Pro 28mm tyres
Weight 7.2kg (size 54)

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