Cannondale’s Synapse has evolved from an upright riding positioned, long-distance bike to this latest generation that combines a lightweight chassis and sorted endurance-biased but speed-focused geometry.
The 610mm stack and 393mm reach on my 58c test bike is combined with a wheelbase that’s just 9mm over a metre. It has a 58mm trail for the fork, which enables a nice snap to the steering without compromising stability.
Cannondale also introduces a change in the bottom bracket drop to 70mm, reducing the drop to make the bike feel right with the trend towards bigger tyres.
The Synapse frame is a very clean piece of design. There are purposeful curves at the junctions and shape transitions throughout the frame. At the back, both the chain and seatstays transition from ovalised at the ends to an almost flat-plate shape through the centre.
This, combined with the specific layup used by Cannondale in its SAVE carbon, enables what is a stiff and light frame (1,100g) to comply enough to null road buzz and vibrations. The frame and fork both feature proper mudguard mounts.
Cannondale’s SAVE hollowgram carbon bar and stem. David Caudery/Immediate Media
The Synapse still adheres to the classic two-triangle approach to frame design. Up front the Synapse fork uses SAVE carbon in the layup, and the slender fork dimensions again aid in vibration damping. Yet, under steering inputs and leaning onto them into corners, there is no hint of flex and no tell-tale brake rub front or rear when climbing or sprinting.
Aiding the ride feel up front is Cannondale’s SAVE hollowgram carbon bar and stem, which eschews a standard round clamp in favour of a crescent-shaped cradle that the bar sits into. The bar is attached to the stem via bolts that go straight through it and into the stem. It gives the aero advantage of a one-piece bar with the adjustment of a standard bar.
On the road the SAVE bar feels noticeably compliant compared to standard bars. Hold the Synapse bar on the hoods or on the tops and its compliance adds comfort, but get down in the drops and there is very little in the form of flex when sprinting.
It’s a clever design and adds a lot of character and performance. I’d opt for this model, with this cockpit, over the slightly cheaper Shimano Ultegra Di2 model with a standard alloy bar and stem.
Shimano’s ever reliable Dura-Ace groupset. David Caudery/Immediate Media
The predominantly Shimano Dura-Ace groupset is mated to Cannondale’s own lightweight chainset. Here it’s with the eight-arm spider rather than the super-lightweight 12-arm found on the top models.
The standard hollowgram crankset is still a light, quality item that shifts as smooth as the Shimano it replaces. Braking with the Dura-Ace hydraulics is spot on.
Cannondale has deviated from Dura-Ace with the brake rotors, but without sacrificing performance as it’s switched to the more cost-effective Ultegra rotors but in the optimal IceTech guise, which gave me smooth-controlled and quiet braking even on long descents in all conditions.
With a great ride feel, smooth shifting and fantastic braking this Synapse has a hell of a lot going for it. Add in handling that’s faster than most endurance bikes and a whip-quick ability to change direction or make corrections if you’ve over-cooked a corner.
However, it’s not without issue. Climbing is where the Synapse lacks a spring in its step, the Fulcrum DB 500 wheels are competent and built to the usual Fulcrum high standards with super smooth-running hubs but they aren’t particularly light at around 1,700g a pair.
They can be run tubeless (though you’d need to add valves and tape) but the Vittorias aren’t tubeless compatible, so bringing the rolling weight down to add more spark to the ride isn’t going to be quick, or cheap, to do.
When I switched out the Fulcrums for a set of my own lighter carbon/tubeless wheels, the Synapse became a true dream machine. As it stands, it’s just very good.
A whip-quick ability to make corrections if you’ve overcooked a corner. Robert Smith
Cannondale Synapse Carbon Disc Dura-Ace geometry
Seat angle: 74.5 degrees
Head angle: 72 degrees
Seat tube: 53.5cm
Top tube: 57cm
Fork offset: 4.85cm
Bottom bracket height: 27.5cm