Cannondale’s SmartSense Synapse brings added safety to the ride

It’s true that for the last few years there has been a shared concern among many tradition-bound cyclists that the bike industry’s growing embrace of modern technology is spoiling the pedaling experience. Recall how back in the day there was pushback against carbon fiber? Of course, eventually, the lightweight virtues of “black plastic” was not just accepted but wildly embraced. Next came the angst about electronic drivetrains. Now, the thought of pulling cable is viewed as Neanderthal! Last but not least was the hysterical rebuke of all things disc-brakes-related. Um, anyone remember the rim brake?! 

And now we have an “on-board awareness and visibility” system courtesy of Cannondale’s SmartSense radar system that’s spec’d on three models in their Synapse endurance bike line. 


The latest incarnation of the Synapse seems to have a general theme to its design—simplicity is better. Gone is the complicated wedge seatpost clamp design and pencil-thin, bespoke seatpost, and back is a simple 27.2 post mated using a standard clamp. Gone also are the press-fit bottom bracket and Hollowgram cranks, which have been replaced by a threaded BB and standard Shimano crankset. With small details like the hidden fender mounts, this bike is built for a rider who is less interested in hyper-optimizing a race bike build and more interested in a “ride and forget” experience. 

The Synapse is available in six frame sizes and two rather calm (gray or mint) color schemes. Lack of flashy finishes notwithstanding, in a day and age of overwhelming billboard graphics, kudos to Cannondale for instead opting for understated graphics.


No doubt the most talked-about item on the Synapse is the proprietary SmartSense light and radar system based on a Garmin Varia. While there are a myriad of accessory light and radar systems on the market, the integrated Synapse system is ready to go right out of the box, including a built-in battery system that cleanly mounts below the front bottle cage. System behavior is controllable via the Cannondale app and is simple to use. The app can also track your ride, so it really is one-stop shopping. SmartSense easily paired with a Garmin Edge 830 computer and created an intuitive overlay on the screen, showing any approaching traffic closer than 140 meters. Upon target detection, the system would automatically change the flashing of the rear light to a pattern that is claimed by Cannondale to be most likely seen by an approaching driver. 

Impressively, SmartSense has the ability to have the rear light act as a brake light when slowing down. We did find that the radar and software needed to figure out how to discriminate against some targets. The system ended up creating warnings so often that we started to ignore them. For example, cars that were two lanes over would show up as possible threats, as well as cars on a road paralleling a separated bike path we like to frequent. We also found that charging the system was finicky and required removing the battery pack from the bike cradle and resetting it. The goal of the bike is simplicity, and one would expect the battery to just charge without having to mess with it. Battery capacity was an issue as well, as we had to charge the battery after every ride to be sure we had enough juice should an opportunity for an adventure ride come up.

The new Shimano Ultegra Di2 gruppo is an excellent choice for this bike. Having a 12-speed compact setup allows for a large range of gearing without big jumps between shifts, and the derailleur charge point is very convenient. The Cannondale is spec’d with 30mm Vittoria Rubino Pro tires, and Cannondale claims room for up to 35mm tires. Some riders wondered if the overall package would’ve been better optimized by coupling Shimano’s lower-line (but equally well-performing) 105 gruppo with some lighter wheels at the same price. 


Riding in the real world for most isn’t best done on a race bike. The roads aren’t all smooth-as-silk tarmac, and you don’t need the aggressive handling characteristics of a race machine. Ride quality can play second fiddle to light weight and aero design. What real-world riders want is something that has all-day ride comfort, as well as handling characteristics that inspire confidence and not nervousness. And here is where the Synapse shines brightest.

Once underway one notices a few things. The frame geometry lends itself to a more upright (and hence comfortable) position. The longish 100.2cm wheelbase adds to the bike’s stable feel without feeling sluggish. This smooth, flowy characteristic is enhanced by the Fulcrum Rapid Red 500 wheels. They are heavy (1740 grams), but what they might take from you in slowing your accelerations and climbing, they give back in handling. All that inertia seems to couple well with the Synapse’s frame design, making carving turns a true delight. 

Of all the many miles ridden on the Synapse, we did multiple rides on an RBA favorite, Old Ridge Route, which is a 100-year-old road that is no longer actively maintained. The descents can be very tricky on a race bike, and a gravel bike is overkill. The Synapse ate up with ease the more than 600 mountainous curves, and the Vittoria Rubino Pro tires absorbed the chunks and floated the sandy sections with aplomb. Although the bike was set up with inner tubes, the Fulcrum hoops are taped and tubeless ready.

The Synapse takes great pains to walk a fine line, balancing weight, aerodynamics and ride quality. After a long day in the saddle, we believe that having a carbon seatpost would add some compliance for a small added price.


For a bike at this price point, the Synapse has the ride feel, handling, proven design and included tech that make it an excellent choice for an endurance bike. This is the bike for riders who want a comfortable, confident, no-muss-no-fuss ride and aren’t concerned with whether or not their steed is the lightest or most aero out there. Where power meters are now considered standard spec on many higher-priced performance bikes, for the non-racy types out there, it’s fair to expect safety features enjoying similar production spec.  

As impressive as Cannondale’s SmartSense technology is, there are two things we would still like to see: 1. Spec the technology on a wider variety of bikes (we’d guess that plenty of riders who opt for the racier SystemSix or SuperSix bikes would appreciate the added safety features), and 2. SmartSense could use another iteration with better battery capacity and ease of use.


SmartSense radar technology

All-day ride quality

Daytime running lights


Price: $5500

Weight: 19.62 pounds

Sizes: 48, 51 (tested), 54, 56, 58, 61

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