Cannondale Synapse Carbon 4 Bike

Color: Cashmere
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Roll smooth, roll fast, roll confident. The Cannondale Synapse Carbon 4 bike is an all-around road machine that's super comfortable and ready to go wherever the road takes you.


  • Lightweight carbon construction features subtle aerodynamic shaping of the frame and fork for riding fast
  • Discreet flex zones in the rear triangle, seat tube and seatpost absorb road chatter and bumps without adding weight or isolating you from the ride experience
  • 10-speed Shimano Tiagra groupset with hydraulic disc brakes gives you 20 gears to thrive on the open road, up and down hills, and on rough pavement
  • Thru-axle is compatible with bike trainers for days when you can't go outside (trainer not included)
  • Compatible with Cannondale SmartSense cycling tech (SmartSense battery, lights and radar not included)
  • Integrated connectivity with the Cannondale App
  • Pedals not included
  • Specs and images are subject to change


This bike comes with Coast to Coast Support, which includes:
  • 1 year of free adjustments (see more below)
  • In-store bike assembly
  • Pickup in store or curbside
  • Bike experts available at 170+ bike shops
REI Co-op Members get more:
  • 20% off shop services
More about our free adjustments:
New bikes go through a normal break-in period, after which they should be readjusted. All bicycles sold at REI include free adjustments for one year after purchase date—as many times as you need. Included: derailleur and brake adjustments, lateral wheel truing, hub and headset bearing adjustments, tire inflation and chain lubrication. Not included: replacement or installation of new components or accessories, any other services. Call your local REI Co-op Bike Shop for more information.

View the Cannondale Synapse Product LineView all Cannondale Endurance Bikes

Technical Specs

Best Use

Road Cycling


Synapse Carbon

Bike Suspension

No Suspension


Synapse Carbon, integrated crown race, Proportional Response size-specific design, 12 x 100 mm thru-axle, thru-tube internal routing, hidden fender mounts


Shimano Tiagra, BSA, 50/34

Bottom Bracket

Shimano BSA



Front Derailleur

Shimano Tiagra, braze-on

Rear Derailleur

Shimano Tiagra GS

Rear Cogs

11-34, 10-speed

Number of Gears

20 gear(s)

Brake Type

Hydraulic Disc Brake


Shimano Tiagra hydraulic disc, 160/160 mm RT64 rotors


RD 3.1, 28h, 21mm IW

Front Hub

Formula CL-712, 12x100mm centerlock

Rear Hub

Formula RXC-400, 12x142mm centerlock

Wheel Size



Vittoria Zaffiro Pro Reflective, 700c x 30 mm

Tire Width

30 millimeters

Handlebar Shape

Drop Bar


Cannondale 3, 6061 Alloy, Compact


Cannondale 3, 6061 Alloy, 31.8, 7 degree

Seat Post

Cannondale 3, 6061 Alloy, 27.2 x 350 mm (48-56), 400 mm (58-61)


Fizik Aliante Delta, S-alloy rails


Not included




Shimano HG54, 10-speed





Size Chart

48 CM51 CM54 CM56 CM58 CM61 CM
Height Range5'2''-5'6''5'5''-5'9''5'7''-5'11''5'9''-6'1''6'0''-6'4''6'3''-6'8''
Effective Top Tube53.354.455.556.757.959.8
Seat Tube Center-Top40.744.348525559
Standover Height71.274.277.378.783.386.8
Head Tube Length10.91314.316.418.721.8
Head Tube Angle (degrees)71.371.473.173.273.373.4
Seat Tube Angle (degrees)737373737373
Bottom Bracket Height272727.227.227.527.5
Fork Offset5.

Sizing Notes

Measurements are stated in centimeters unless otherwise indicated.

How we measure bikes

  1. Standover Height Standover Height is a measurement from the ground to the top of the top tube, measured at the midpoint of the top tube.
  2. Reach Reach is the horizontal distance from the center of the cranks to the center of the head tube, measured at head tube level.
  3. Stack Stack is the vertical distance from the center of the cranks to the center of the head tube, measured to the top of the head tube.
  4. Effective Top Tube Effective top tube is the distance from the center of the head tube to the center of the seat tube/seat post, measured parallel to the ground.
  5. Seat Tube Center to Top Seat Tube length is the measurement of the seat tube, from the center of the cranks to the top of the seat tube.
  6. Head Tube Length Head Tube Length is measured from the bottom to the top of the head tube.
  7. Head Tube Angle Head Tube Angle is the acute angle between the head tube and the ground (measured towards the rear of the bike)
  8. Seat Tube Angle Seat Tube Angle is the acute angle between the seat tube and the ground (measured towards the rear of the bike).
  9. Bottom Bracket Height Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the cranks.
  10. Wheelbase Wheelbase is the measurement from the center of the front axle to the center of the rear axle.
  11. Chainstay Length Chainstay Length is the measurement from the center of the cranks to the center of the rear axle.
  12. Fork Offset Fork Offset, or rake, is the distance from the front axle to a line drawn parallel to the center of the head tube or steering axis.

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