Ride Quality
Most of the endurance bikes need to make a sacrifice in either efficiency of ride quality, and though it’s minimal, the Cannondale Synapse Hi-Mod Disc Red sacrifices a bit of front end and saddle stiffness for comfort. But for most, that sacrifice will be well worth it—the feel of this bike is pure bliss. The tall head tube allows for a more comfortable shoulder/head position, and the skinny seatpost and aggressively shaped stays and down tube adds some suspension over big bumps and sustained rough roads. The 28mm tires, and the capability of up to 30mm, depending on tire brand, allows lower tire pressures and increases compliance—as do the 22mm deep (25mm wide outer), all-purpose carbon wheels.  

Stiffness-to-Weight/Power Transfer
And here’s the sacrifice: The bottom bracket and cranks are surprisingly stiff and efficient, making for excellent power transfer under heavy load but lower cadence. But when the cadence ramps up in the saddle there’s noticeable flex in the seatpost. Also, when up in sprint or power climbing position on the Cannondale Synapse Hi-Mod Disc Red, the head tube and fork give a little under the power, and the skinny bars flex noticeably. While I don’t know how much actual speed this will cost the rider, it definitely “feels” slower and does not help confidence. That said, it’s the lightest in the group at 15.9 pounds—really light even for a non-disc bike. That’ll definitely make up for some of the flex, especially when climbing.

Climbing/Efficiency
The sitting position is so comfortable that the rider can focus solely on the legs during long climbs, and keep the shoulders and neck relaxed. Combined with the stiff bottom bracket and crankset, the Cannondale Synapse Hi-Mod Disc Red is an excellent climber overall, and the longer the better. But as mentioned above, the saddle bounces under a high cadence and the front end flexes when powering up a steep grade or in a sprint, especially when out of the saddle.

Descending/Handling
Despite the aforementioned front-end flex, descending was much like the typical endurance bike—a bit slower to initiate a turn, but buttery smooth through the arc. Testers said they didn’t feel as comfortable completely diving into a tight corner, as say on a race machine, but that’s rare in this type of riding anyway; plus the trade-off there is the slightest pressure on the bars and the race bike wants to go there, even if you don’t! However when braking in a hard turn there was noticeable flex in the fork: The Cannondale Synapse Hi-Mod Disc Red features standard quick release axles instead of thru-axles—assumedly to save weight—and with the added torque of disc brakes they just don’t provide enough stiffness, especially in the front end.

Components: Drivetrain, Shifting and Brakes
The SRAM Red on this build is an outstanding group. The combination of ultralight weight and durability is perhaps unmatched—we still don’t understand how their one-piece cassettes can be so light and stiff! But shifting is definitely a different animal versus Shimano (and Campy, but none in this group had the Italian components). For those who crave the mechanical “feel” of shifting, nothing provides that like SRAM’s single-lever system. The push is harder, especially when shifting to an easier gear. Shimano users will have a bit of adjustment time. It’s hard to match the precision of Shimano as well, and I do feel that Red falls a tiny bit short here. But there’s very little difference overall in performance, and it really comes down to a personal choice of “feel” and weight.

The Red brakes also showed comparable performance to DA. Modulation in fact felt just a tad smoother, but overall power was a tad under—both negligible differences. However the levers and hoods are definitely more ergonomic on Red. Perfectly curved levers allow the rider to keep one finger securely on the lever on descents (and one finger is all you need with these discs!), and a firm grip on the hoods or drops. And the large, upturned nob on top of the hoods is perfect for grabbing on and copping a low-profile, power position while providing plenty of torque in the upper body, although we’d prefer a carbon bar for optimal performance and comfort.

Wheelset
Testers were very impressed with the house brand CZero wheelset on the Cannondale Synapse Hi-Mod Disc Red. At an impressive 1370g (without rotors) they’re comparable to many ultralight, all-around rims from the big names, and they’re just as smooth, quiet and responsive. Straight pull spokes with a slightly oversized hubs keep things stiff and they remained perfectly true through our test process, despite over lots of rough surfaces. The only major issue we found is the use of quick-release skewers instead of thru-axles, which keep weight down but didn’t provide ample stiffness to handle the torque of discs, especially under hard braking.

Value
If a lightweight, pure endurance machine is what you’re looking for, and you don’t mind sacrificing a bit of out-of-the-saddle explosiveness, Cannondale’s Synapse Hi-Mod Disc Red is an excellent option and a fairly good value—especially if you’re a SRAM fan. It’s not cheap, especially considering other big-name bikes are similarly priced with electronic shifting. But SRAM Red isn’t cheap either, and this is a very well-built and well-appointed bike. Plus some riders simply want mechanical shifting despite the price, and some other brands don’t give that option at this price point. Cannondale didn’t skimp on anything here, from carbon wheels to the handmade Schwalbe One tires, both of which are often areas they can save a few bucks.