Originally Posted by
Gav888
So, my understanding (please correct me if im wrong) is CP60 is the highest power output you can maintain for 60min, and CP20 is the same but for 20min, CP3 is 3min and so on. If thats the case, if I ride max effort for 60min and record my average speed that speed would effectively be my CP60 speed, of FTS - Functional Threshold Speed?
..., etc etc but when using a turbo it should be a good estimate shouldnt it?
Does this sound right?
Absolutely. As long as your computer has an average speed function down to 10ths. Our strain gauges are no more precise than a spoke magnet & calculator.
While you're in the middle of your trial, both values (W & mph) are jumping all over the place (stochasticity, I've heard it called), but at the end of it, an FTS is still a helpful training tool when you have fixed resistance.
And you can take little steps yourself to solidify your data. I scoffed when I first read in the Coggan book about using CP20 minus 5% to calculate your FTP, but riding a one hour time trial with your trainer is indeed grueling. I had three vastly different values when I rode three hour-long trials. But my 20-minute trials are in a pretty tight shot-group. (Oh geez, here comes the HTFU crew...)