One question we are regularly asked is how accurate is the Wattbike and how does it compare to the SRM crank. The answer is that both testing tools are accurate to within +/- 2%, although they use different measurement systems. We have created a video to demonstrate the comparability of the data and posted it on our Youtube channel at www.youtube.com/wattbike, so if you already have data from using an SRM crank, you can compare with the data that you are getting on your Wattbike, but remember to ensure that your SRM crank is correctly calibrated.