There are several power meters that will work on a Cannondale MTB crankset:
Left Crank Arm Power Meter
Stages Cycling makes a left side crank arm for 2014 or newer Cannondale Si, Hollowgram Si and Hollowgram SiSL2 cranks. This power meter will replace your current left side crank arm and will measure left leg power.
Please 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 Meters
The power2max NGeco Cannondale MTB Power Meter is our go to power meter for Cannondale MTB cranksets. It’s a superb power meter in that it’s accurate, extremely durable, measures the power from both legs, is reasonably priced and allows you to keep your current Cannondale crankset.
The power2max NGeco Cannondale MTB Power Meter is compatible with Cannondale SI, SISL or SISL2 cranksets.
Please note, the power2max uses a 104 BCD chainring configuration. So you will need a power2max compatible MTB chainring as well.
Pros: Moderately priced, VERY reliable, don’t have to change crankset, measures both legs
Power Meter Pedals
MTB power meter pedals can be installed on any MTB crankset. We have both the Garmin Rally XC and the SRM X-Power.
Pros: Easy to install, works on any bike, can move from bike to bike, don’t have to change crankset