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Cannondale Synapse Hi-Mod Disc 2018 review

28 Feb 2018

There's no such thing as one bike that does it all, but the 2018 Cannondale Synapse Hi-Mod Disc comes close

Cyclist Rating: 

Buy the Cannondale Synapse Hi-Mod Disk now from Evans CyclesThanks to Google constantly spying on our every mouse click, we know that the Cannondale Synapse is one of the most searched for bikes on the internet.The reason is fairly obvious: it’s a very good bike. Look through past reviews, including my own, and you will struggle to find anything but high praise for Cannondale’s endurance bike.As such, it would be tempting for Cannondale to avoid making any big changes to the Synapse, but this 2018 edition represents the most significant redesign since the Synapse went full carbon back in 2013. And what Cannondale has done is rather intriguing.

With a growing appetite for bikes that offer ‘versatility’ – that is, being able to cope with a variety of road surfaces – many brands have pushed their endurance models closer to the off-road end of the market, with the addition of mechanical suspension systems to absorb road shocks.Cannondale has done no such thing. In fact, it has done the opposite.   

Go your own way

The 2018 Cannondale Synapse Hi-Mod Disc is now closer in style to the company’s pure road racing machine, the SuperSix Evo.It’s both lighter and stiffer than its predecessor, and even the geometry and performance attributes of the frame and fork are now more aligned with its race-bred brethren.What is the reason for this? Cyclist called Cannondale designer David Devine to find out.‘We designed the new Synapse conscious that the endurance rider still wants a lightweight, responsive bike, the same as a bike racer,’ he says.‘I think this direction becomes natural once we accept that suspension belongs in a different category. I’d call that “all-road” and we have the Slate for that.‘To me this [endurance] category is better served having race bike performance, but melding in some of the functional features that make an endurance bike its own: room for bigger tyres, mudguard compatibility and disc brakes.‘These aren’t passive bikes – they’re made to be pushed – and so the Synapse gets the same construction tech
as our lightweight race bikes such as the SuperSix Evo and SuperX.‘There’s not a whole lot of fluff, fewer bonded pieces, more integrated manufacturing. Its inherent beauty is in how simple and refined it is.’I agree with Devine’s stance regarding the endurance road category. I feel it’s often misunderstood.Front ends don’t need to be so tall that they require you to duck low flying aircraft, and while no one wants to be beaten up by their bike, most of us don’t need gooey-marshmallow levels of compliance either.What can be said with certainty is that everybody likes to go fast, whether it’s placing highly at a gran fondo or just giving your mates a kicking up the local climb. On those points, this new Synapse delivers.Where its predecessor was ‘very good’, this new model has stepped up to ‘excellent’. It has a snappier feel and sharper handling, with poise in the corners and stability at speed.As promised, it feels much closer to the SuperSix Evo. I was able to test the Synapse back to back with the current SuperSix Evo Hi-Mod Disc, and in terms of acceleration and handling I struggled to definitively split them.What’s more I could run with the stem slammed on the slightly taller front end of the Synapse, where
I needed a 20mm spacer stack on the SuperSix, so for my fit dimensions the Synapse arguably looked more ‘pro’. So what does split these two bikes? The answer is comfort. There’s nearly 6cm difference in the seat tube length of the two (size 56cm) bikes, resulting in the Synapse having a lot more exposed seatpost that can flex under impacts.This does much of the hard work towards smoothing out the ride feel single-handedly.Then there are the tyres. With clearance for up to 32mm, plus tubeless-ready wheels, the Synapse offers lots of scope to fine-tune the feel.In testing I used the supplied Vittoria Corsa G+ 28mm tyres (which actually measured 29.5mm) with inner tubes, and gradually dropped the pressure with each ride.Starting out at 85psi, I came down in 5psi increments until I was riding at just 60psi, which felt amazingly smooth, although by this point I felt I was pushing my luck a bit and risking pinch flats.Had I converted to tubeless, though, I would have been happy even at this low pressure. I settled eventually on 70psi front, 75psi rear as a happy medium for the superior grip and comfort it offered without seeming to impact significantly on rolling speed.Set up in this way the Synapse was sublimely smooth over even the most pitted road surfaces, and grip in corners was confidence-inspiring.What the new Synapse delivers is a noticeably racier feel compared to the outgoing model, but with no less comfort.When I consider the other bikes I’ve tested recently in the endurance sector – Trek’s Domane SLR, Specialized’s Roubaix S-Works, BMC’s Roadmachine 01 and Canyon’s Endurace CF SLX Disc – it seems clear to me that Cannondale has set out to distance itself from those brands.The new Synapse is not as noticeably comfortable as some of those other bikes, especially the Domane with its plush rear end and the Roubaix with its sprung shock absorber upfront, but that’s not its main purpose.The Synapse feels every bit like a race bike until you get home from a four or five-hour ride. That’s when you realise how well it has been taking care of you.The question I was left pondering is has Cannondale made this new Synapse so capable it will harm the sales of its SuperSix Evo? It’s possible.For many would-be SuperSix customers (myself included), unless all you plan to do is race, the new Synapse is arguably the smarter choice.

Buy the Cannondale Synapse High-Mod Disk now from Evans Cycles 


Cannondale Synapse Hi-Mod Disc 2018
Frame Cannondale SuperSix Evo carbon
Groupset Shimano Dura-Ace Di2
Brakes Shimano Dura-Ace Di2
Chainset Cannondale HollowGram SiSL2
Cassette Shimano Dura-Ace Di2
Bars Enve carbon road compact
Stem Enve carbon road
Seatpost Cannondale Save carbon
Saddle Fabric Scoop Shallow Pro
Wheels Cannondale HollowGram SL 
Weight 6.8kg (56cm)


Cannondale Synapse Hi-Mod Disc 2018: Launch, gallery and first ride review

James Spender | 10 July 2017Cannondale’s all new Synapse has finally landed, and while it might look very similar to the old, there are some subtle yet highly effective changes, plus an all-new bar-stem setup that’s meant to aid comfort while being more aerodynamic.‘The Synapse dates back to 2002, but it was called the Road Warrior,’ says Cannondale’s David Devine, in reference to the aluminium version created to have room for 25mm tyres and more relaxed geometry.That bike moved into a Synapse-branded machine in 2006, and then got a carbon rethink in 2013, heralding a successful 2014 Classics season under Peter Sagan and a dominant place in the endurance road market.

Given that dominance, it’s little surprise this new Cannondale Synapse bears such a striking resemblance to the last generation. If it ain’t broke, don’t fix it. But, do improve it, a lot.

So what’s new with the Cannondale Synapse Hi-Mod 2018?

Actually, pretty much everything.Most noticeable is the new cockpit, called the SAVE Systembar (Synapse Active Vibration Elimination). It’s comprised of an alloy stem bolted to a carbon bar in a fashion that makes the whole thing look one piece.Why not actual one piece? Simple, Cannondale wanted there to be pitch adjustment and easily interchangeable stem lengths for the bar, the lack thereof being a common complaint about one-piece bar-stems.To achieve this the stem cups the centre of the bar, but doesn’t clamp all around it like a conventional setup. It’s held in place by four bolts on rocker-style washers, meaning the bar can be rotated forwards or backwards through 8 degrees of pitch to get the desired angle.It’s terribly neat, works a treat and looks the part.Crucially for an endurance bike, the Save bar’s tops are thin and flattened such that Cannondale says they have measured up to 15mm of deflection in the lab (although that figure, says Devine, is more like 4-6mm in the real world).On top of the bar is a little rubber doofer that plugs a hole, into which a Garmin or Wahoo out-front mount can be inserted. Again, all very neat, and Cannondale even ships it with a Fabric out-front Lumaray light, which clips neatly under a bike computer.As is becoming increasingly popular, Cannondale has put a cut-out on the top of the down tube a few inches behind the head tube to accommodate Shimano’s new Di2 charging port.With SRAM Red eTap on the bike there’s a blank insert that covers the cut-out; with mechanical shifting there’s a plate that houses cable bosses.In keeping with the clean lines approach, hydraulic disc hoses run inside the fork leg and through the down tube and chainstay and into flat-mount disc brake callipers.Those disc brakes are now held in place with thru-axles, a departure from Cannondale’s previous quick release approach on the last generation.Curiously the rear is a Syntace 142x12mm and the front a Maxle 100x12mm – the rationale being this is the most popular combination when it comes to wheels available.The fork is asymmetric, much like the recent BMC Teammachine Disc’s, meaning it’s significantly beefier on the rotor side to deal with the extra asymmetrically distributed torsional braking forces of disc brakes (the rear chainstays have been given this treatment too).It’s also available in three sizes in order to preserve the handling characteristics, stiffness and prevent toe overlap across different frame sizes.Size 44 and 48cm frames get a narrower 1 1/8” lower bearing and 60mm fork offset; 51 and 54cm 1 1/4” and 55mm offset; 56, 58 and 61cm a 1 3/8” and 45mm offset.The idea is the larger bearings, steerer tubes and head tubes help keep the bigger sizes stiff in the head tube, as more gangly tubes are more prone to flex. As such, Cannondale reckons the new Synapse is 9.4% a stiffer in the head tube than before.The fork sheds a claimed 116g, down to 367g, and the frame loses 220g over the previous Synapse, making for a claimed 950g frame and meaning a 6.8kg build is perfectly achievable.Cannondale’s done this in the usual way, by changing the lay up schedule and tweaking the carbon/resin mix.The swoops and curves of the stays have been exaggerated yet further for more compliance, and the ‘Power Pyramid’ a cut out in the bottom of the seat tube, is still evident on the higher spec bikes, lower spec get a flared but filled in seat tube, as the Pyramid is an expensive thing to mould, says Cannondale.Frame geometry has also be subtly tweaked, with the head tube measuring 173mm in a size 56cm (the previous generation was 186mm). It’s also slightly steeper than before, making the Synapse’s upright position just that tad more aggressive.Interestingly, Cannondale has made the front mech braze-on mount removable, so running a 1x drivetrain needn’t leave you with an unsightly protrusion where your mech used to be.There are several off-the-shelf 1x bikes in the range, denoted with the suffix ‘SE’ and specced with voluminous 650b tyres. Speaking of which, the Synapse can now accommodate up to 32mm 700c tyres, and has hidden eyelets for mudguards.Rounding things off is the Save seatpost, just 25.4mm in diameter and shaped to exploit the flexibility of carbon for a more comfortable ride without sacrificing lateral stiffness.

Cannondale Synapse Hi-Mod 2018: First ride

I’ve ridden several iterations of the modern Synapse, both rim and disc, and while I very much like those bikes I’ve always preferring the feel and stance of their racier brother, the SuperSix Evo.I was therefore pleasantly surprised to find myself in a far more aggressive position on the new Synapse thanks to a more aggressive take on endurance geometry, where a shorter, steeper head tube and a few other tweaks, such as a slightly shorter wheelbase, conspire to make for a lower slung, more nimble position.There’s still a sense of the comfortable uprightness that made the early Synapses so popular, but with just a few millimetres here and half degree adjustment there the new bike has sharpened up immensely.When the road tips up the frame and fork stiffness is palpable. Cannondale reckons the Synapse is second only to the BMC Roadmachine in terms of BB stiffness in the endurance category, and class leader in head tube stiffness and, given the way it stands up to big bar wrenching efforts, I found no reason to doubt this.The low weight was undoubtedly helpful too up the climbs, but where the Synapse really comes into its own is on the descents. The rougher, the twistier the better.With 28mm rubber fitted courtesy of Vittoria’s excellent Corsa G tyres and run at just over 80psi, the Synapse glided round bends like a oiled up Aladdin’s carpet, with all the adhesion of araldite.In fact, that’s the word I found myself using time and again to describe the Synapse: sticky. It stuck to the road with exceptional grip, which really came into its own under heavy braking, where I was thankful for the bullhorn height of the Sram eTap hoods to brace my hands against as the bike would slow up rapidly while my body wanted to carry on moving forward.You just can’t get the same performance with rim brakes or a bike without such levels of grip.There is a caveat here though. The tyres are a massive part of this equation, as too the heat – I test rode the Synapse around the shores of Lake Como in Italy, where the tarmac was pretty much in a perpetual state of heat haze.Different rubber in different climes and it might not be such a lyrically waxed story.Yet, I’d still bet on the Synapse delivering the stability, assuredness and poise on descents in a variety of conditions, and that’s down to the frame.There is a noticeable spring in its step, and this must certainly help with the Synapse to track surface undulations as opposed to skipping over them.If there’s a downside it's that there was some latency with feedback as the frame muffled vibrations, but overall, my hands, forearms and posterior says that’s a good thing.More longer term testing will follow, but for the time being first impressions are the new Synapse is a mightily impressive beast that is surely destined to rival the SuperSix Evo for Cannondale racing supremacy.

See and for morePhotos: Gruber Images1516896689371

Cannondale Synapse Hi-Mod Disc 2015 review

Stu Bowers | 1 May 2015The notion of building a do-it-all bike has always seemed to me like chasing a pot of gold at the end of a rainbow and that exactly what the Cannondale Synapse has always been.When you try to be all things to all men you run a high risk of setting yourself up to fail. Take low-fat cheese, for example.You’re messing with what is by definition a substance laden with fat and calories in an attempt to satisfy those who want to limit their fat intake – and in my experience the result is something wholly unsatisfying.Sometimes compromise is necessary if you want the full experience, and you’re better off playing to your strengths and accepting the trade-off in other areas.Some of the best, most exciting bikes I’ve ridden have been true to this principle, being excellent in particular areas of performance and, as a consequence, less so in others. Then I rode this Synapse and my views changed.Back in the spring of last year, not long after Cannondale initially launched its new Synapse as a cobble-slaying weapon for Peter Sagan’s Classics campaign, I got to ride a SRAM Red-equipped version of the top-end Hi-Mod frame platform, with traditional mechanical calliper brakes, around Mount Etna.I was more than a little impressed with its capabilities as it dealt with every challenge thrown at it by the mountainous Sicilian roads.My lasting impression was that Cannondale Synapse had hit a rarely achieved sweet spot where compromises were the only things missing.So the prospect of putting the latest cream of the Synapse crop – the stealthy, Hi-Mod Black Inc Disc – to the test, with a dream spec, comprising Shimano’s Dura-Ace Di2 shifting and hydraulic disc brakes, excited me immensely. I took to the road with some high expectations.

Disc brakes

I think we’re past the point of arguing for and against disc brakes now and must accept they will soon be commonplace on road bikes. In time, they may even replace calliper brakes completely.Aesthetically, I’m still to be convinced because they remain too close to bastardised mountain bike systems and not sufficiently ‘road-like’ for my money, but when it comes to performance, I’m convinced, hands down.Cannondale has put more thought than many brands into its very neat internal cable routing of the hydraulic hoses – the entry point of the front-brake hose into the fork crown is particularly noteworthy.The Synapse also goes against the grain by using smaller, 140mm rotors where most bikes opt for more visually intrusive 160mm rotors on the grounds of improved heat dissipation.The performance of the hydraulic Shimano R785 brakes on the Synapse is exceptional, with superb lever feel and progressive modulation that lets you sense precisely where you’re at in the braking power-curve so you can adjust your speed with total confidence.I certainly had no cause for concern using the smaller rotor size. The discs’ predictability in all conditions is clearly superior to rim brakes, a fact that was emphasised when switching between bikes – something I’m fortunate enough to do a lot working for Cyclist.With the British spring throwing practically every type of riding condition at the Synapse during this test, the performance differences were highlighted further, and disc-brake technology on road bikes is only likely to continue improving.Equally topical as another ‘yet to be fully accepted’ trend are the voluminous 28mm Schwalbe One tyres that Cannondale has elected to fit on this Synapse.Just like the brakes, they instilled confidence by providing good road holding under braking and grip aplenty when leaning into corners. Any preconceptions I had about increased weight, drag and rolling resistance were soon quashed.The tyres helped to uphold the Synapse’s lively and agile persona when accelerating and seeking rapid direction changes, and didn’t rob it of any top-end pace.To make the most of any potential increase in comfort from the larger air volume it’s important to experiment with using lower tyre pressures.I weigh about 67kg and settled on around 85psi for the best balance of comfort, grip and speed. However, tyres are only a single part of the equation, and credit must also be given to the success of the system as a whole, including the excellent Vision Metron 40 wheelset, which complements and extends the feeling of stability delivered by the frame and fork.

The frame

A good deal of the assertiveness of the frame comes from the success of its standout design characteristic – the split seat tube – which stoutly sits atop the widened bottom bracket shell.Added to the mix is Cannondale’s own super stiff SiSL2 chainset and oversized BB30A bottom bracket standard, resulting in a pedalling platform that barely flinched under my strongest efforts.As an aside, the single-piece CNC’d aluminium chainrings and spider combined with the Di2 front mech made for the sweetest of front-gear shifts.Cannondale has been generous but not excessive with an 18.6cm head tube on the Synapse, such that slamming the stem will still achieve an aggressive riding position, but for the less flexible rider there’s plenty of room to manoeuvre. The Synapse won’t short-change you in any area, and I’d honestly feel equally happy head down in a tight and twisty crit race as climbing the longest Alpine passes.The bike certainly delivers on descents, too, and I could count on one hand the number of bikes I’ve previously said that about.I’d be nitpicking in the extreme to find many faults in this bike. The frame does appear to have sacrificed a fraction of its compliance compared with its non-disc sibling, I can only assume as a result of the necessary strengthening to key areas of the chainstays and seatstays, as well as the fork.

It’s most noticeable up front where there’s a bit more road shock coming through the bars. Keeping this in perspective, though, it’s still perfectly tolerable, and indeed the bike as a whole is still up there among the most comfortable I’ve ridden.While on the subject of comfort, the 25.4mm seatpost is a stroke of genius. It’s such a simple way to soften the blows the rider experiences at the rear, and it even visibly flexes under bigger impacts.Rule #12 says the correct number of bikes to own is n+1 (where n = the number of bikes currently owned).The rule also suggests taking heed of its subsection: s-1 (where s = the number of bikes it would take for your partner to leave you).For my money, the Synapse Hi-Mod Disc Black Inc is the closest a bike has come to disproving the n+1 hypothesis and, in fact, may make it easier to stay in a happy relationship, too, providing you’re not already flying dangerously close to s.Rating - 4.5/5


geometry chart

56cm Claimed
Top Tube (TT) 561mm
Seat Tube (ST) 520mm
Head Tube (HT) 186mm
Head Angle (HA) 72.5
Seat Angle (SA) 73.5
Wheelbase (WB) 1005mm


Cannondale Synapse Hi-Mod Disc 2015
Frame Cannondale Synapse Hi-Mod Disc
Groupset Shimano Dura Ace Di2 9070
Brakes Shimano R785 disc brakes
Chainset Cannnodale Hollowgram SiSL2
Bars Cannondale C1 Ultralight
Stem Cannondale C1 Ultralight
Seatpost FSA SLK carbon, 25.4mm
Wheels Vision Metron 40 Disc
Tyres Schwalbe One, 25c
Saddle Fabric Scoop Shallow


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