With the Synapse endurance racer, Cannondale was once one of the pioneers of comfort-oriented racing bikes that were consistently tailored to the needs of leisure cyclists. Today, the latest generation offers much more than the classic, purist road racing bike: with the integration of useful electronics, the US brand continues to pursue the new direction of its endurance bike. The predecessor model launched in 2022 already stood out from the mass of marathon racers from other manufacturers. It was the first to integrate a battery and a permanently mounted lighting system into the racing bike ex works. This also included a distance radar at the rear, which warns of approaching cars, and a dynamically reacting rear light, which is intended to increase the attention of car drivers. Everything is controlled by sensors and managed via a smartphone app. The fact that the bike prioritised road safety and everyday practicality over the usual sales arguments was considered a bold innovation at the time. The revised version now comes with all the familiar and new features, but aims to improve many things and eliminate weaknesses in detail.
The basis is a carbon frameset that is strongly orientated towards the SuperSix competition bike used by the EF Education-EasyPost team. Striking examples are the heavily tapered seat tube, the filigree seat post and the flow-optimised steering head. As a result, the bike not only looks much more modern, but also benefits technically from the update. The seatpost now absorbs bumps much better and the fork has also been redesigned for more suspension capacity: The latest version of the Synapse catches up with the most comfortable competitors such as Canyon's Endurace or the Giant Defy, or in other words: it rides almost like a sedan chair even on bad roads.
Quiet vehicle
During the test rides, it is also noticeable how quietly the bike rolls. Especially the SRAM Rival gearbox impresses with its quiet running and smooth, flawless shifting behaviour. We hardly notice any other noises, even the freewheel only hums quietly. We also find the steering behaviour exceptional: At high speeds, the bike rolls almost unwaveringly straight ahead; in fast corners, it even has to be pushed a little. On the other hand, the Synapse reveals a particular strength on hills: even at walking speed on steep climbs, it is stable and requires hardly any levelling out. The significant gear reduction, which also helps less trained riders over steep hills, can be savoured with pleasure. The bike would even cut a fine figure off the tarmac; with space for tyres up to 42 millimetres wide, the frameset can also be used as a gravel bike. The high weight remains a weakness; our test bike with SRAM Rival and simple DT Swiss aluminium wheels weighs a good nine kilograms. This has an effect on responsiveness when pedalling; even among endurance racers in this price range, the vast majority are more lively.
There are many improvements to the electronics. The battery has been moved to a storage compartment in the down tube, which also fits a full puncture repair kit. The handling reveals attention to detail: when you open the solid lid, an LED illuminates the inside. The battery can be removed without unplugging and plugging in a cable, or charged from the outside via a USB-C port. In an emergency, the battery can be used as a power bank or torch. The highlight: In addition to the lighting system and radar, the battery can also power the gears on models with SRAM AXS. Instead of the small batteries, there are adapters on the rear derailleur and front derailleur that connect the components to the main battery. Their consumption should have little influence on the running time, as the SmartSense battery offers around 20 times the capacity of the shifting batteries. The small front light under the stem is hardly noticeable, but turns out to be a fully-fledged driving light that can illuminate the road well. We find the omission of the radar display on the handlebars a bit of a shame: a compatible bike computer or at least a smartphone is required to use this feature. Another minor flaw is that the functions are only available with SRAM AXS drivetrains; there are no Shimano variants with SmartSense. Unfortunately, the 5299 euro test bike is the cheapest entry into the new world. The Synapse Carbon starts at € 3499 with a mechanical Shimano 105, but without a battery and lights. With the top model with Ultegra Di2 and spare carbon wheels, there is also a classic long-distance racing bike that is passably light at under eight kilograms.
Cannondale Synapse Carbon 3: Test grade, price, geometry, equipment, measured values, advantages and disadvantages
- Price: 5299 Euro
- Weight of complete wheel: 9.3 kilos
- Frame sizes: 48, 51, 54, 56, 58, 61
- TOUR grade: 2,2
Geometry
- Seat/top/head tube: 520/570/170 millimetres
- Stack/Reach/STR: 597/384 millimetres/1.55
- Stack+/Reach+/STR+: 666/580 millimetres/1.15
- Wheelbase/caster: 1,045/61 millimetres
Equipment
- Drive/gear shift: SRAM Rival AXS (2x12, 46/33, 10-36 t.) | Note: 1,0
- Brakes: SRAM Rival AXS (160/160 millimetres | Note: 1,0
- Tyres: Vittoria Rubino Pro 32 millimetre | Note: 2,5
- Impellers: DT Swiss E 1800 Spline
- Impeller weights: 1,536/1,980 grams (f./h.)
Measured values
- Weight of complete wheel: 9290 g | Note: 4,3
- Driving stability: 8.85 N/mm | Note: 1,3
- Rear comfort: 85 N/mm | Note: 1,3
- Comfort front: 86 N/mm | Note: 2,3
- Ride/ bottom bracket stiffness: 57 N/mm | Note: 1,3
Cannondale Synapse Carbon 3: Advantages and disadvantages
Advantages
High level of ride comfort, great safety plus with radar and lights
Disadvantages
Electronics only in combination with SRAM gears
How TOUR tests
Jens Klötzer
Editor
