An endurance machine that's still stiff enough to feel fast, the Cannondale Synapse Disc has a slimmed down frame that means the disc brakes come weight penalty free

The 2018 Cannondale Synapse saw a complete redesign, with an entirely new carbon lay up dropping the weight by 220g in a size medium.

The Synapse itself, born in 2006, has always been known for its excellent combination of confident handling, relaxed geometry and versatility – and all that is still present in the newest version, which comes with exclusively disc brakes.

Shaving off excess weight hasn’t impacted ride quality one iota, and the Synapse was easily one of our best rides this year – earning it a place in the 2017 Editor’s Choice hall of fame.


Within the endurance road bike category the Synapse has always been a highly regarded machine that has won many awards and fans. Its design objectives centre around compliance, a smooth ride, plus a high level of integration and versatility.

The new 2018 Cannondale Synapse is a real weight weenie – for an unpainted model it has a claimed frame weight of 918g and fork weight of 372g for a size 56cm (adding paint increases the overall weight by 150-200g) – the overall package is 220g lighter than former versions.

With all models disc only, Cannondale describes the reduction in weight as “getting disc brakes for free”, which is a nice way of looking at it.

SAVE yourself from fatigue

SAVE is at the heart of the Cannondale Synapse and stands for Synapse Active Vibration Elimination. Essentially this is an umbrella term for design features that increase comfort and compliance.

The proprietary 25.4mm seat post is the same as that found on the SuperSix Evo Hi-Mod and is designed to offer deflection. Deflection and vertical compliance are also built into the stays and fork.

Power Pyramid for targeted stiffness

The Power Pyramid bottom bracket is retained from the previous version. This design feature is intended to reduce weight where it isn’t needed, allowing the engineers to place that carbon in more structurally important areas of the bottom bracket, increasing torsional stiffness in the process. Put simply, Cannondale claims the Power Pyramid saves weight while retaining stiffness. It is found on the Hi-Mod top-end framesets, but is absent on other models.

Asymmetry continues to feature and, according to Cannondale, this combined with the refined carbon layup has significantly improved the stiffness.

Cannondale Synapse Disc

Cannondale Synapse Disc Power Pyramid Split Bottom Bracket

The new Synapse has also been optimised for each size, meaning that a 49cm is comparable in stiffness to a 61cm frame. This is an area that has been neglected by many bike designers in the past, so it’s reassuring for those buying a size at the extreme end of the size range. Further to this, Cannondale has refined the sizing, making it a more linear progression. Cervélo was one of the first brands to do this and it can make buying the correct size easier. Cannondale has also designed women’s-specific models with different frames and geometries.

A knack for translating geometry

Being an endurance bike, the geometry is more relaxed than that of most out-and-out race bikes. In a size 56cm, the Cannondale Synapse is 2cm higher in stack and 1cm shorter in reach than a SuperSix Evo. The seat tube and head tube angles are very similar to those of the Evo, though. Overall the geometry is not as relaxed as many endurance/sportive bikes, with Cannondale intending to strike a balance between comfort and the exhilaration and excitement of getting long and low.

Cannondale’s engineers have a knack for translating geometry into great handling, and in testing we found the bike reminded us distinctly of the highly revered SuperSix Evo.

Cannondale Synapse Disc

Cannondale Synapse Disc on test

The geometry achieves a good balance and stiffness is great when gunning it out of the saddle. We found descending on the Synapse an absolute joy. The confidence-inspiring ride feel of the SuperSix Evo is also present here and the improvements in head tube stiffness are noticeable. Our tester was able to take the bike down a number of technical descents and when really digging into tight switchbacks the Cannondale Synapse carves beautifully like a slalom skier.

Stability and smoothness are very good indeed, something which I feel is really enhanced by the wide 28mm tyres fitted to our test bikes.

The primary take away from our time with the new Cannondale Synapse was that it offered an exciting ride, with handling that feels more like that of a race bike than a sportive bike. The geometry is more relaxed than the Supersix Evo’s: the wheelbase is a bit longer, the fork rake a little longer, it’s a little shorter and a little higher at the front end but Cannondale hasn’t gone for as relaxed a frame as most endurance bikes out there and I like this.

To further expand the versatility of the Synapse, the new design features clearance and mounts for mudguards. The mounts are subtle and hidden on the frame. This creates a nice clean look when they are not required, yet adds potential versatility if and when you need it. Cannondale also say that even with those 28c tyres that come supplied with the bike, it’ll support mudguards, meaning you can retain the comfy, grippy 28c tyres and keep a dry bum! Some feat considering the girth of the tyres.

We tested the top of the range Hi-Mod frameset equipped with SRAM Red eTap HRD. However, on going to sale the top Hi-Mod bikes came fitted with Dura Ace Di2 at £7,799.99. The entry level option comes with Shimano 105 at £2,199.99 and there are two women’s models in the 11 bike line up.