On our Davinci we would need identical crank-based power measurement units each of which needs to support a single, 36t chainring (on the left side). This is probably too expensive a solution given we're never going to race, but intriguing nevertheless. A better solution might be a Powetap hub for our single bikes which have identical 12-27 cassettes. I will look into the iBike as well. It appears it may develop useful information at a reasonable price, but I certainly wish the website were more forthcoming about the nature of the algorithms used short of revealing any of their precious IP.