I’ve personally tested the last three iterations of the Cannondale Synapse. In all honesty, it’s been a wonderful bike in each version, but after testing the latest SuperSix EVO, I was wondering if the Synapse would even be necessary in Cannondale’s vast lineup. I mean, you could just put slicks on the new SuperX and call it an endurance bike. However, after learning more about the changes made to the 2025 Synapse, along with its capabilities and performance, I’m 100% here for it.
UPDATE: As luck would have it, we have now ridden and reviewed the 2026 Cannondale Synapse Carbon 4, if you want to know how that budget build performs.
Historically, endurance bikes don’t get the same aerodynamic tuning as race bikes, but Cannondale wanted to change that with the new Synapse. Ridden by Lachlan Morton as he raced around Australia last year, the Synapse is built to be speedy, comfortable and capable over LONG distances.
As I’ve looked back at the previous three Synapse models I’ve tested (2014, 2018, 2023), the 2025 Cannondale Synapse clearly gets everything right where the other models fell short. Of course, plenty has changed since 2014 — with modern endurance bikes offering so much capability that I find those older models almost laughable by today’s standards. Only 28mm tire clearance? Clunky SmartSense wires and systems running everywhere? Those days are thankfully gone with proper 42mm tire clearance and a simplified SmartSense platform that finally lets me get over the fact that it’s still wired. But what else is worth writing home about with the 2025 Synapse?
Real-world geometry
Let’s face it, racy fits aren’t for everyone. Thankfully, the “slam that stem” crowd isn’t quite as prevalent these days, but honestly, having 30mm+ spacers on any bike will never yield the best performance and handling. Instead, the new Synapse offers a healthy amount of stack and shorter reach for a more comfortable, upright position — naturally, without spacers. Looking it over, I could ride the 56cm without any spacers and satisfy the “slam that stem” crowd. With the new Synapse, you can have a sleek-looking bike and a proper fit.
Tire clearance and comfort
I love the added tire clearance — even though I would prefer a dedicated gravel bike. With the Synapse, you can drop some gravel tires, or simply install some high-volume 35-38mm slicks for a confident and comfortable ride across everything. Big tires will certainly add comfort, but the frame itself is also 20% more compliant and is built with Proportional Response Construction so all riders of all sizes can enjoy a unified ride feel.
World Tour aerodynamics
Tested and optimized to deliver aero performance on par with the best race bikes on the World Tour, the 2025 Synapse will not hold you back — at least where aerodynamics are concerned. The sleek tube shapes clearly allow airflow to pass by without unnecessary drag.
SmartSense 2.0 and StashPort
While I’m still not 100% stoked on wired lighting, the integrated battery port and streamlined head and taillights are now acceptable whereas the 1.0 versions were hideous. I still would prefer rechargeable lights, but this is a great improvement. And, the StashPort provides downtube storage for days using the included StashBag. As an added bonus, the SmartSense battery is also configurable to power your SRAM AXS front and rear derailleur. Interesting.
