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Review: Cannondale Synapse Carbon Disc road bike is the perfect all ’rounder

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details
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Introduced last year, the 2018 Cannondale Synapse was designed as an endurance race bike. Whether you wanted to go fast or go long, or both, its combination of a stiff but forgiving frame, big tire clearance, and intentional compliance could deliver. Add in much improved looks over earlier models, sleek cable routing and a hidden seatpost binder, and it looks very much like the total package riders who just like to ride a lot. Here’s how it performed…

2018 Cannondale Synapse Carbon Disc Overview

2018 Cannondale Synapse Carbon Disc brake endurance road bike is one of the best long distance and all around road bikes tested

The 2018 Synapse is offered in two frame trims – the HiMod at the top, and this Carbon model with BallisTec layups. Both versions benefit from their SAVE micro suspension at the seat- and chainstays, fork, and seatpost. And both get some of their “Si” Systems Integration, though nowhere near the level of the latest SuperX or Scalpel bikes. No, there’s no asymmetric rear end or wheel builds here, letting you swap in any modern thru axle disc brake wheelset.

Well, technically, it is an asymmetric design, but only in that driveside and braking areas are reshaped and strengthened to handle those stresses. The seat tube is offset to the left to clear the front derailleur and maximize cross section, and the chainstays are shaped differently to improve tire clearance and use a double chainring.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

More to the point, the Si takes the form of functional improvements like modular cable ports that can be swapped for Di2 junction box holders on bike equipped with electronic shifting.

2018 Cannondale Synapse Carbon Disc brake endurance road bike has micro suspension built into the frame flex points

And flattened, shaped stays and fork legs designed to improve vertical compliance without losing lateral rigidity. Others do this, Cannondale’s been doing it longer, and it shows through in the ride quality.

2018 Cannondale Synapse Carbon Disc brake endurance road bike has massive tire clearance

The frame is rated to clear 32mm (measured) tires, it’s shown here with the stock Vittoria Rubino Pro 700×28 tires.

Not noticeable are the three different fork offsets, lower bearing sizes and frame layups used across the size spectrum. All done to keep the ride quality consistent across the the line, whether you’re riding a 44 or 61 (58 tested).

2018 Cannondale Synapse Carbon Disc brake endurance road bike with flex seatpost to improve rider comfort

The last piece of the SAVE puzzle is their 25.4 seatpost with built in flex. On some flex posts, I can look down while pedaling and see the saddle’s nose bobbing up and down. It’s not as dramatic here, but as a package with the frame, it all seems to work quite well to mute the physically draining white noise of crappy roads.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

2018 Cannondale Synapse Carbon Disc brake endurance road bike with one-piece SpideRing chainring crankset combo

The one piece of Si we love to see on their bikes is the one-piece SpideRing chainring on their lightweight Si cranks. It’s stiff, light, and looks bad ass. It also shifts well. As with any 50/34 combo, there’s an increased likelihood of the chain trying to catch the big ring when you’re in the small/small combo – proper drivetrain setup is key, and best to just shift the front before getting completely cross chained in the 34.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details 2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

Half the story of this bike is its comfort. The other half is performance. Note how the seat tube comes flush to the edge of the BB shell. And that the BB shell and downtube are way oversized compared to the actual crank spindle. They say it’s slightly stiffer than prior models, with the fork/head tube getting the biggest improvement, and that it’s comparable to many modern road race bikes. The idea is to deliver race level performance when it’s time to stand up and hammer or take a pull on your local “A” group ride.

The geometry plays a part, too. It sits comfortably (pun intended) between a crit bike and a fondo bike, with a lower BB for better handling, but slightly more upright riding position. Sounds counterintuitive, but it works.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

Finishing things off are tidy appointments like flat mount brakes…

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details with sleek hidden seatpost bolt

…a hidden seatpost binder…

2018 Cannondale Synapse Carbon Disc brake endurance road bike with hidden fender eyelet mounts

…and stealth fender mounts. Frames ship with a fender mount brake bridge part to provide the centered fender mount.

Side note: You may recall that “Power Pyramid” split seat tube from the launch photos (and on their website), but that feature is only on the HiMod models. Don’t fret – Cannondale’s Director of Product Marketing Murray Washburn says you get about 98% of the benefit from this standard ovalized seat tube. With the Power Pyramid, they’re concentrating all of the material out on the edges where it’s doing more good, so stiffness to weight is improved, but in the end you’re talking about minimal if any weight savings and marginal gains. Unless you’re a pro, the real reason to upgrade to the HiMod frame is that you’re saving 180-200g depending on paint and frame size. The HiMod frames use a higher modulus carbon, letting them use less of it to accomplish the same frame stiffness and ride quality.

Pricing, Specs & Actual Weight

As tested, the Cannondale Synapse Carbon Disc Dura-Ace comes in at $4,999. It’s spec’d with a Shimano Dura-Ace mechanical shifters/derailleurs with hydraulic disc brakes, Ultegra 11-30 cassette, and save for the Cannondale Si crankset (50/34), Fulcrum Racing 500 wheels, Vittoria Rubino tires, Cannondale alloy bar and stem, and a Fabric Scoop saddle.

Above it is the Carbon eTap model ($5,999) and below it an Ultegra Di2 ($4,199) bike. HiMod models start at $6,499.

2018 Cannondale Synapse lightweight carbon endurance race road bike true endurance machinery geometry

2018 Cannondale Synapse lightweight carbon endurance race road bike true endurance machinery frame and fork weight

This chart shows HiMod frame weights, add 180-200g for the Carbon models. They say a 56 Carbon is about 1,100 grams.

2018 Cannondale Synapse Carbon Disc brake endurance road bike actual weight

Actual weight for the complete bike (size 58) with tubes in the tires is 17.44lb (7.91kg).

A nice added bonus is the included integrated Garmin mount that slots through the stem’s face plate. They’re working on a Wahoo version, too.

2018 Cannondale Synapse Ride Review

2018 Cannondale Synapse Carbon Disc brake endurance road bike is one of the best long distance and all around road bikes tested

I’ll get straight to it: The Cannondale Synapse rides exactly like I want a road bike to ride. It’s comfortable yet quick. Stable without being slow. Drive it hard into a corner and it’ll oblige. Or take your hands off the bars to stretch and it’ll keep pedaling along perfectly straight. And if you happen upon a stretch of gravel, don’t be afraid to take it.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

The Synapse is not intended to be a gravel bike, and I wouldn’t use it as such. But get out on the country roads or unincorporated areas and sometimes that asphalt can ride like gravel. Patches, chip seal and weather worn roadways can ride rough, but often lead to the best places. Low traffic rides, rolling hills and interesting scenery are often my rewards for taking random turns or heading well outside the county limits.

These leisurely but long rides make up about half of my road riding, and the Synapse is the perfect partner here. The frame’s features combine to provide stable, comfortable riding that makes its benefits obvious. This isn’t theoretical vibration minimization that may leave you feeling fresher after hours in the saddle. This is real bump absorption that I could notice immediately and often.

2018 Cannondale Synapse Carbon Disc brake endurance road bike review and tech details

The other half of my rides are short sprints and intervals, my attempt at building power and speed for cyclocross season. Here, the Synapse is quite capable, too. The entire drivetrain section responds quickly, as it should.

The only area where the comfort outweighed all out performance was occasional front rotor rub under hard efforts. It didn’t require dramatic side-to-side pitching in standing sprints, either – any respectable out of the saddle effort or stomping up a climb could induce a rhythmic “tchssh tchssh” noise from the front brake. To be fair, a lot of disc brake road bikes do this, so it’s not a Cannondale problem, just something worth noting.

From a practical perspective, the Synapse is all positives. It benefits from all the right Cannondale technologies and designs without requiring custom offset cranks, chainrings or wheels. It rides like a dream, comes in a wide range of sizes, trim levels and prices, and is reasonably light. If your idea of road riding is just to get outside and enjoy a ride, sometimes long and slow, sometimes hard and fast, I’d highly recommend giving the Synapse a test ride.

I’m enjoying the bike so much, Cannondale’s letting us hang on to it for a while longer to test other components. This will include new wheels from Shimano and Industry Nine, along with wider tires. Stay tuned…

Cannondale.com

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34 Comments
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Mardigus
Mardigus
6 years ago

Got the 2017 Synapse. This is my first road bike and it’s a really sweet ride. I’m positioned comfortably and the bike just want to run. Good for me because I’m old

Tom
Tom
6 years ago

while I dislike the constant evolution of bikes as it starts to resemble an arms race, this is the kind of bike i can get behind – 95% of the speed of a race bike, with the ability to pedal it out on dirt/gravel roads without fear of crashing or breaking wheels.

D-con
D-con
6 years ago
Reply to  Tom

Agreed 100%
This looks like a great choice for the vast majority of rides and riders.

dalancroft
dalancroft
6 years ago
Reply to  D-con

Who happen to have $5k laying around.

trekmbikes
5 years ago
Reply to  dalancroft

My thoughts exactly.

Crash Bandicoot
Crash Bandicoot
6 years ago

Is it me or is that front wheel cock-eyed to the driveside?

ChrisC
ChrisC
6 years ago

Disc brakes = dished front wheel…

JBikes
JBikes
6 years ago
Reply to  ChrisC

All wheels are checked for “dish” to ensure the rim runs directly center of the frame dropouts. “dish” is often used improperly to refer to the asymmetric spoke angle.
In no world is a disc wheel designed to run offset of center because of “dish”. That wheel is improperly made and the builder doesn’t understand what a dish tool is for.

Crash Bandicoot
Crash Bandicoot
6 years ago
Reply to  JBikes

Yeah I’ve built up plenty disc wheels and I’ve never had them offset to one side (well okay my first MTB wheels were a little rough). I have seen plenty of Cannondales with misaligned dropouts though (including the super x that was reviewed here)

O. Tan
6 years ago

I didn’t require dramatic side-to-side pitching in standing sprints, either – any respectable out of the saddle effort or stomping up a climb could induce a rhythmic “tchssh tchssh” noise from the front brake. To be fair, a lot of disc brake road bikes do this, so it’s not a Cannondale problem, just something worth noting.

Hmm, I own the new Roubaix and can’t seem to recall this “tchssh tchssh” noise from standing sprints. Cause I wonder what other disc road bikes has this noise as well

mika
mika
1 year ago
Reply to  O. Tan

Hello friends,

Mid 2023. I have a Synapse Al on mechanical disc brakes, I am outside the range of the Synapse models reviewed here.

But believe me, Synapse flies uphill when rocking amazingly and there is no hint of contact between the disc and pads even close.

Cannondale Forever…

Roman Pohorecki
6 years ago

Pitty there are no rack mounts…the Synapse would make the perfect light commuter or tourer. Specialized Diverge and Jamis Renegade offer this feature on their carbon models.

lop
lop
6 years ago

This bike isn’t intended to be a tourer, nor to compete with the Diverge or the Renegade. There are myriad bikes in this category, and not every bikes needs to be all things to all people. And if it’s REALLY an issue, and you must take this thing out on tour, then get some bikepacking bags, which attach sans rack.

Gary
6 years ago

FWIW, the alloy-framed version of this bike has rack mounts.

Ian Ezzi
Ian Ezzi
6 years ago

Love this sort of bike, but wish a manufacturer or two would consider trying the same thing but with mini-v brakes. Offer the same clearances but cheaper, lower weight, greater simplicity, and with the right pads, perfectly adequate, quiet performance in the wet (having ridden through a wet, slushy, cold Scottish winter, I can attest to this). No rub under sprinting either.

I guess going custom is the only way!

Scott
Scott
6 years ago
Reply to  Ian Ezzi

I can’t think of anything that will rub more than mini v’s with normal road levers. They do not open nearly far enough to allow any amount of rim clearance.

Ian
Ian
6 years ago
Reply to  Scott

Ah, good point, I’m running Campy style levers with the little button quick release. Leave the quick release ‘open’ so the lever sits further away = 1-2mm pad clearance either side. Prob wouldn’t work if you have small hands (or Shimano shifters…)

lop
lop
6 years ago
Reply to  Ian Ezzi

What a terrible idea.

Gary
6 years ago

Curious to know what happened to the the “Save System semi-integrated Stem/Handlebar” that was supposed to be on the higher-spec versions of this bike.

datotb
datotb
6 years ago
Reply to  Gary

My understanding is that prototypes showed an issue with Etap lever compatibility and maybe another unforeseen issue as well? Hopefully next year….

Andrei Ionescu
Andrei Ionescu
6 years ago
Reply to  datotb

E-mailed Cannondale, and they said it was a delay with the manufacturing process for the 2018 models. Considering the 2019 models also lack the systembar, i tend to think it is actually a functional problem with the original design.

datotb
datotb
6 years ago

I use a 2018 Synapse SE Apex for my 7 mile commute to work. Full fenders and 30mm tires for the win. No rack but a good top tube bag and a Revelate seat bag do the trick just fine.
I like that bike so much I just purchased the HiMod Dura Ace Di2 version as my weekend warrior bike. It really is just about perfect for all type of rides. I am not planning on road racing anymore so even though the new Specialized Tarmac Disc was quite appealing for fast weekend rolls the Synapse won for its overall versatility and comfort.

VeloKitty
VeloKitty
6 years ago

There was some kind of production problem with the Cannondale SAVE handlebars, so they were removed from all builds. They might reappear for 2019.

Kona 68
Kona 68
6 years ago

No “tscha tscha” on my etap synapse since last october. Maybe it is the hrd brake. On the other side, the bike is as you discribe it – I love my new ride! Eager to ride the high mountains – up and down!

tyler durden
6 years ago

no dished wheels? you wouldn’t know from their opaque lingo-dumping product page.

tyler durden
6 years ago
Reply to  tyler durden

no dished wheels? you wouldn’t know from their opaque lingo-dumping product page.

Cannondale’s Director of Product Marketing Murray Washburn would do well to emphasize this.

Brian Dwyer
Brian Dwyer
6 years ago

Question: It appears that this bike is much darker in color than the same model on the Cannandale website. What’s up with that? Is the color lighter like on the website or darker like here?

Mike
Mike
6 years ago
Reply to  Brian Dwyer

Thinking the same thing, the colour difference is huge

Andrei Ionescu
Andrei Ionescu
6 years ago
Reply to  Brian Dwyer

Yeah, the colors in the catalog/website do not match the reality/

Bryin
Bryin
6 years ago

17.5lb bike for $5K? No thanks…

Bryin
Bryin
6 years ago

BTW, you could buy a Trek Emonda SLR w/ Ultegra (rim brakes) for LESS money ($500) LESS! And run 30c tires and with rim brakes it is 3lbs lighter… Uhh that seems easy….

Mattv
Mattv
5 years ago

I have the ultegra SE carbon. I also have a lot of other bikes to compare it to. The synapse wheels are really poor. The wtb KOM rims are great for tubeless, but incredibly tight for replacing tubes. Spokes are garbage. Factory tensioning is garbage. The bike is slow handling, feels dead in a sprint or uphill, but it is comfortable. I’ve ridden this bike for thousands of miles and have a good basis to compare it to other things. Get it if you don’t know the difference, or just want a touring bike feel. The sizing is a little strange, it has a long reach. I had to go to a 90mm stem on a 54 to get a good position, but my knees hit the bars on climbs

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