Cannondale Synapse Hi-Mod Disc Red eTap review

Cannondale’s endurance machine packs in more than just a comfortable ride




  • Handling
  • Specification


  • Limited height adjustability of stem

Price as reviewed:


Nestled within Cannondale’s road range between the aero SystemSix and the lightweight SuperSix sits the Synapse, Cannondale’s long-standing endurance machine. With an emphasis as much on rider comfort as speed and performance, the Synapse has seen plenty of change and refinement to get it to this, the latest version.

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Buy now: Cannondale Synapse Hi-Mod Disc Red eTap at Wheelbase for just £4499

Cannondale has never been one to stint on unique features and clever tech and this new Synapse Hi-Mod Disc is no exception. And all rolled up with enough acronyms to keep all but the most ardent logophile busy for a week, with such proprietary technologies such as Si, SAVE and BallisTec to name the most prominent.

Read more: Cannondale SuperSix 2019 range explained

This Disc Red eTap model sits neatly in the middle of the top-tier Hi-Mod section of the Synapse range. Consisting of three models, the Hi-Mod range is eclipsed by the 15 versions of the standard Synapse that sit below it.

It’s the frame that signifies the separation in the Synapse range. The Hi-Mod, as its name suggests, makes use of a mix of high and ultra-high modulus carbon fibres as the backbone of the frame structure. This allows the Hi-Mod frame to retain a high level of stiffness without needing a huge mass of material to provide that stiffness, keeping overall weight to a bare minimum.

This Hi-Mod BallisTec frame material is then formed into tubing with wall thicknesses and is specially shaped to provide the Synapse with a level of compliance above that expected from a frame still expected to be ridden to a such a high level. Aimed not just at providing a smoother ride, it’s as much about creating a faster rolling platform, Cannondale calls this tuning of the frame SAVE (Synapse Active Vibration Elimination).

But it’s not just about creating a frame with the same, tired old ‘vertical compliance’ feature/marketing gumph. The SAVE PLUS (one of four different types of SAVE found on Cannondale’s road bikes) does of course feature flattened chainstays and seatstays of an almost helical shaping but this is combined with the curved shaping and offset dropouts of the fork to provide an almost suspension-like feel to allow the wheels to track much better over imperfect road surfaces. This is merely the first benefit of SAVE’s trifecta of buzz-killing behaviours. The Synapse also makes use of a carbon lay-up where the fibres are oriented in such a way as to trap the vibrations within the layers and hopefully dissipate before they can make it to the rider.

Rounding out the SAVE features, the seatpost diameter has also been reduced to 25.4mm to offer more movement and flex as well as Cannondale doing away with the external seat collar and re-siting the clamping mechanism within the frame.

The hollow Power Pyramid bottom bracket is found on all Cannondale Synapse Hi-Mod models. Its main job is to increase stiffness while reducing frame weight.

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.

The Synapse uses geometry that stretches the head tube and slackens the head angle slightly over the more race-oriented SuperSix, presenting the rider with a more relaxed front end for all day riding comfort. Cannondale also supplies the Synapse Hi-Mod with a 30mm deep shaped headset cap/spacer to boost the handlebar height even further with the aim of reducing fatigue. This does, however, present its own issue as customisation of the cockpit height is restricted without organising and sourcing a separate top bearing cap and spacer. The chainstays are also stretched out longer than a SuperSix to add stability to the Synapse, especially useful when descending at speed late into a long ride.

cannondale synapse hi-mod

Carbon headset/cap spacer stops you dropping the front end too far.

As you would expect for a bike at this price point, the kit spec reads like a cyclist’s Christmas wish list. Front and centre (and as implied by the name) is SRAM’s inaugural wireless Red eTap drivetrain. Providing not only an extremely clean aesthetic to the bike, Red eTap supplies the rider with twenty two gears and front and rear shifting courtesy of just two shift buttons. It certainly has the edge over other groupsets from a technology perspective but shifting can be a little slow and imprecise when compared to the latest Shimano Di2 electronic drivetrains (something SRAM has refined with the latest 12 speed AXS eTap groupsets). But, it’s wireless. And that is awesome…

As is proving increasingly popular and rightly so for so many reasons, the Cannondale Synapse Hi-Mod comes fitted with the hydraulic disc brake version of SRAM Red eTap. We don’t have to bleat on about how disc brakes provide more consistent and reliable stopping in all weathers and how the lighter action reduces hand and arm fatigue over long distances but Cannondale obviously understands the advantages as the entire 2019 Synapse range comes bedecked in the hub-based stoppers.

cannondale synapse hi-mod

SRAM Red HRD disc brakes stop the Synapse with safety and ease.

We really rated Cannondale’s own brand Knot 64 wheelset fitted to the SystemSix reviewed recently and the Synapse is no different. Here the wheels are Hollowgram Si versions. The 35mm deep, disc specific full carbon rim is mated to Cannondale’s own superlight Hollowgram hubs with DT Swiss internals. Not only light and fast rolling but the wide, 19mm internal rim width combine well with the 28mm Vittoria Corsa tyres to create a large air volume. The result is impressive comfort, grip and speed.

Barring the sublimely comfortable Fabric Scoop carbon saddle, the rest of the kit comes courtesy of Cannondale. The cockpit includes the well shaped, shallow drop Escape Hanger bar whilst the stem features an integrated GPS device mount. This needed regular tightening to ensure it kept my Garmin in the correct position.

The carbon SAVE seatpost is a spindly 25.4mm diameter to add even more flex.

The ride quality of the Synapse Hi-Mod surpasses that of many of its endurance-category rivals. It delivers an engaging and exciting ride more akin to a race bike than a super-relaxed sportive machine. The geometry provides the Synapse with handling sharp enough make cornering, descending and rapid direction changes almost subliminal, although personally I would prefer to drop the stem further on the steerer to put a little more weight over the front tyre for a little more confidence.

Buy now: Cannondale Synapse Hi-Mod Disc Red eTap at Wheelbase for just £4499

The Cannondale Synapse Hi-Mod also retains a sprightly feel when putting down the power and is still capable of skipping up the road when really kicked, reminiscent of the racier SuperSix. This can obviously be attributed to the stiff bottom bracket junction and responsive wheels and again gives the Cannondale Synapse Hi-Mod the edge over the competition.


One of the original dedicated endurance machines has continued to impress us with regards to its stunning performance in almost all areas of riding. It blurs the boundary between race and sportive bike incredibly well and seemingly offers a real 'best-of-both-worlds' package.


Frame: Synapse Disc Asymmetric BallisTec Hi-MOD carbon
Fork: Synapse Disc Asymmetric BallisTec Hi-MOD carbon
Groupset: SRAM RED eTap hydraulic disc
Handlebar: Cannondale Escape Hanger Carbon
Stem: Cannondale C1 Ultralight
Seatpost: Cannondale SAVE Carbon
Saddle: Fabric Scoop Shallow Pro
Wheelset: Cannondale HollowGram Si, carbon clincher disc
Tyres: Vittoria Corsa 700x28c
Weight: 6.92kg
Colours: Sage grey
Sizes: 51-61cm