The Cannondale Synapse Carbon 3 was bar none one of the best looking bikes in the test.
The goal of an endurance road bike is simple: Make it comfortable without sacrificing all modicum of stiffness and efficiency. The path to reaching this desired end, however, is full of interesting twists and turns. Or in the case of the Cannondale Synapse Carbon 3, a host of unique tube shapes.
Utilizing what it calls its Save Plus micro-suspension system, all the Synapse bikes benefit from an eye-catching scalloped seat tube and spindly 25.4mm diameter seatpost that are designed to flex together, providing greater comfort when seated. By splitting the seatube (Cannondale calls it Power Pyramid) before it joins the 73mm wide BB30 bottom bracket, engineers were able to implement a larger downtube and beefier chainstays, so stiffness is preserved, but keep weight in check.
Meanwhile, the 25.4mm seatpost, by far the slimmest in this test, subtly moves fore and aft, providing greater impact deflection. This effect is further accentuated by integrating the post clamp into the frame, leaving more of the seatpost exposed.
Judging by tester feedback, the design works fairly well. During extended time on the rough and often washboard-strewn roads north of Boulder, Colorado, riders reported that the Cannondale Synapse Carbon 3 did a solid job of vibration absorption.
The Cannondale Synape Carbon 3 is essentially the same bike members of the Cannondale Pro Cycling team race at Paris Roubaix. We tested it out on the Boulder Roubaix course.
“It tracked well and never felt too harsh, even in places where there were those nasty braking bumps,” said one tester. “I was also surprised at how well it handled. Front end steering and cornering was really solid, more so than some of the other bikes in this test.”
Of course this is not a pure bred race bike. Cannondale’s similarly spec’d SuperSix 3 Ultegra’s head tube is more than 3cm shorter than the 20.8cm found on our size 58cm test rig. Additionally, the bike’s 101.3cm wheelbase avails plenty of stability, especially at speed. Here’s a comparative breakdown of key geometry numbers for all the bikes in this test using a baseline of 56cm frame size.
Additional bump damping comes courtesy of a fork with offset dropouts, which adds compliance, and a set of twisted seat stays where the length of the actual composite fibers is longer than the stays themselves, meaning vibrations take longer to reach the rider. It’s heady stuff that nets a great looking bike at the same time.
“I really liked the look,” said one tester. “Lots of cool lines and a solid paint scheme, too.”
The Cannondale Synapse Carbon 3 also gets mostly high marks in the spec department. It was one of the few bikes in this test to get name brand wheels set, in this case a set of Mavic Aksiums wrapped with Mavic Aksion tires.
“Wheels is usually a place where companies can cut corners, so this was a pleasant surprise,” said one tester who is also a former WorldTour team mechanic. “I’d always rather see non-house brand wheels because you can expect to get better trickle down technology from a major wheel maker such as Mavic.”
An ultra-slim seatpost and unique seat tube shape conspire to keep weight down, but bump and vibration absorption high.
The drivetrain is ever-reliable 11-speed Shimano Ultegra, save for an FSA SL-K Light 50-34 compact crankset. Normally we don’t like broken groups, but these carbon cranks do help keep weight down. The Cannondale Synapse Carbon 3 was the third lightest bike in the test at 17.11 pounds sans pedals (and No. 2 among the size 58cm testers we got in). Here’s a full breakdown of prices and weights for all the bikes in this test.
It’s also worth noting that the Cannondale Synapse Carbon 3 is one of only two bikes in the test that utilizes Shimano’s long cage Ultegra rear derailleur, which allows for use of an 11-32 cassette. (The Specialized Roubaix SL4 is the other). The resulting 34-32 low gear combination makes this a true steep climb tamer. “You can basically spin up anything,” said one tester. “This bike is made for those crazy long Italian gran fondos with a million feet of climbing.”
Spec is rounded out with the usual mix of house brand components. The compact bend of the Cannondale C2 handlebars made it easy to spend extended time in the drops. The Fizik Aliante saddle was reasonably comfortable. Cable routing is fully internal.
Too Road Racy?
The most frequent complaint leveled at the Cannondale Synapse Carbon 3 was perhaps it didn’t fully embrace the endurance bike ethos, instead residing somewhere between the proverbial road race and all-day ride realms.
“For me it just wasn’t quite as comfortable as some of the other bikes in this test,” noted one tester. “Some people will like that, because it has a little more of a race bike feel. Some might want to look elsewhere.”
This sensation could in part be remedied by going with wider tires. The Cannondale Synapse Carbon 3 comes stock with 25c tires, but it passed our wide tire test, easily accepting a set of 27c Challenge Paris Roubaix, which do a great job of smoothing rough road.
The Cannondale Synapse Carbon 3 passed our wide tire test, easily accepting a set of 27c Challenge Paris Roubaix that measure closer to 30mm.
Other testers flinched at the bike’s tall headset cap, which when combined with the rangy headtube made for a very upright affair. The good news is that you don’t like the look or are simply looking for a more aggressive riding position, you can swap it out for a shorter one.
The Cannondale Synapse Carbon 3 is yet another top contender in the endurance road bike niche. It utilizes a highly unique frame design to smooth out rough roads without sacrificing stiffness and efficiency, and has a solid parts spec for a bike in this price range. It was also one of the best descenders, with solid front end steering and precise cornering control. Just make sure to take a few extended test rides before pulling the trigger. Some riders will appreciate its more racy feel and tight handling characteristics; others may want to look for a bike with slightly more all-day ride compliance.