There are several power meters that will work a Cannondale One road crankset:
Left Crank Arm Power Meter
The Stages power meter is compatible with Cannondale One cranksets.
Please also note, whenever you are installing a left side power meter crank arm, you need to confirm you have 10mm of clearance between the left crank arm and the chainstay in order for the sensor to clear. Please see the image below.
Pros: Affordable, easy to install, don’t have to change crankset
Cons: Measures left leg power only
Spider Power Meter
The power2max power meter is also compatible with Cannondale One cranksets.
Please note, some Cannondale cranksets have a 120 BCD (which is usually indicated on the outside of your chainring). If this is the case, you must purchase new 110 or 130 BCD chainrings to use with your power meter. We recommend Praxis chainrings with this power meter.
Pros: Moderately priced, VERY reliable, don’t have to change crankset, measures both legs
Power Meter Pedals
Power meter pedals can be installed on any crankset. We have several models to choose from.
Pros: Easy to install, works on any bike, can move from bike to bike, don’t have to change crankset