Cannondale Synapse Carbon 105 review

The Cannondale Synapse Carbon 105 is a popular endurance bike that still has a spring in its step

Cannondale Synapse Carbon 105
Cycling Weekly Verdict

The Synapse is an endurance bike that encourages you to sit up and take in your surroundings. If you want to unlock its other side - a snarling beast of a grand tourer that’s as happy to beat your mates off the lights or up a climb in hour one of your ride as it is to be your sight-seeing companion in hour six, you’d be best off upgrading the wheels. It’s safe to say that while it may not have any whizz bang elements of some of its rivals that’s because it does what it does with fuss free understatement and refinement. That’s what you want in an endurance bike, and this remains one of the best at it.

Reasons to buy
  • +

    Sprightly handling

  • +

    Great at reducing road buzz

  • +

    Solid spec

  • +

    Good value

Reasons to avoid
  • -

    Heavy wheels

  • -

    Frame probably due an update

If you’ve been in the market for an endurance road bike anytime in the last fifteen years the Cannondale Synapse, first launched in 2005, has probably been on your shortlist.

However, the last frame update first broke cover in 2017 and so it is now arguably showing its age, bereft as it is of fancy elstometers or funky tube junctions. To look at this 105 equipped carbon framed model in its rave battleship colour scheme it looks like an archetypal road bike.

Cannondale Synapse Carbon 105

The tubes are flatted and truncated in the way we so often see in modern bikes, but it doesn’t scream mile-munching machine. Can it still measure up to its more swaggering rivals?

The first thing you notice hopping aboard the Syanpse is the geometry. On our 54cm test rig the stack height is 16mm higher than its racier sister bike the SuperSix Evo and the reach a tad smaller by 2mm. That’s less upright than both the Trek Domane and Specialized Roubaix, both of which have higher stacks and shorter reaches, and pretty similar to the Giant Defy which is a bit lower but a bit shorter too.

Cannondale Synapse Carbon 105

I usually run a couple of centimetres of spacers on a bike this size but the high front end felt instantly odd to me and I slammed it onto the conical headset cap less than ten minutes into the first test ride. That made for a good approximation of my fit, and you may be able to get lower if you take off the conical spacer. If you like a really low front end you probably shouldn’t be looking here. With the stem slammed the bike still felt tall-ish but pleasantly so.

Many brands lengthen the wheelbase of their endurance model to aid stability but the Synapse wheelbase is the same as the Supersix, at 1008mm and the fork trail is only ever so slightly shorter at 56mm compared with 58mm. All this undoubtedly contributes to one of its best features, which is an assured but agile handling downhill. It’s a joy to descend on. It carves through the corners with a reassuring confidence but responds to sudden changes of direction when you need it to with ease.

Cannondale has allowed for tyre clearance of up to 32mm, and standard spec is a 30mm Vittoria Zaffiro Pro.  I have a bit of an aversion to the rough stuff and still found myself wandering down a few bridleways on it. It might feel a bit odd to be that far from the black stuff on a road bike, but this machine is just as comfortable tackling light gravel tracks as it is your club’s resident Bobby Big Watts.

Cannondale Synapse 105 spec

The specification is solid for a bike at this price point. Most of the finishing kit is Cannondale’s own decent reliable stuff. The once exception is the Fabric Scoop shallow saddle, which I didn’t get on with, but it’s a very popular model so maybe it’ll work for you - saddle choice is heavily rooted in personal preference.

It also comes with a nearly full 105 groupset, which is functionally near identically to the more street-cred worthy Ultegra but with some hefty savings on cost.

Cannondale still insists on using the BB30a bottom bracket standard, which despite its long held reputation for creaking, has never caused me any problems. This is rendered necessary due to the asymmetrical frame, which beefs up the driveside to create additional stiffness and therefore response. It does however mean you have to use a third party chainset and the one specced here is Cannondale’s, somewhat basic looking, One crankset with FSA chainrings.

Cannondale Synapse Carbon 105

We’ve previously had one weight in it 833g (with a 52/36 rather than the 50/34 here), compared with a claimed weight of 758g for a Shimano 105 version. That helps to contribute to the 9kg overall weight of our test bike. However, the cranks are known for being both reliable and stiff.

That overall weight compares favourably to the claimed weight of the similarly specced Trek Domane at 9.89kg (albeit in the next size up) and is in line with the Giant Defy. None of those endurance bikes aims, nor claims to be, feather-light.

Not helping with the weight are the wheels which are unlikely to inspire excitement with formula hubs laced to Cannondale’s own aluminium rims. They’re a fairly run of the mill set of hoops that weight in at north of 2kg.

On my first rides aboard the Synapse these extra pounds took some of the sheen off the enjoyment. Yes it was very comfortable, it handled great and transferred my pedalling into forward motion with efficiency, but I was yearning for a little more pizazz to go with it’s mellower charms.

Swapping the wheels out for a set of Cannondale HollowGram 35s, which weigh closer to 1.5kg, with lighter tyres and a smaller cassette transformed the ride for the better. Now the bike possessed almost all of the road buzz-killing comfort that it did before but with a far greater spring in its step. It felt like what the frame deserved.

My pressing would see it leap out of corners and sprint for signs with enthusiasm rather than the begrudging fulfilment that had characterised it before. It didn’t transform it into the most razor sharp racer but unlike one of those bikes it’d happily settle into cruise mode and encourage you to appreciate the world as it passed by you.

At this price point, a quality frame that really comes alive with a wheel swap is not uncommon, and it does mean the bike can grow with you over time.

Synapse value

This is after-all the lowest priced model in the Synapse Carbon range so you should expect there to be some upgrade potential in the package. That’s a good thing, it means your hard earned is being spent principally on a quality frame that will reward improvements in components as they wear out or your budget allows further down the line, it’s worth noting the frame will take Di2 electronic shifting should you wish.

Cannondale Synapse Carbon 105

At £2,200 it’s highly competitive against similar bikes too. The equivalent Trek Domane is £2,550 and the Specialized Roubaix Sport, which also forgoes the 105 chainset in favour of a Praxis Alba, is £2,600. Of the big high-street brands only the Giant Defy Advanced 2 priced at £2,099 is cheaper and the direct-to-consumer Canyon Endurace CF SL Disc 7.0 is the same price.