Originally Posted by
Beaker
Just to be contrarian, I personally think it's better to establish a local place to do your FTP test. 20mins and local makes it much easier to retest and track your performance compared to a ride you'll do relatively infrequently.
I actually think this is good advice. I use OLH as a ftp benchmark for this reason. It's even <20min, but I've done enough 20min efforts to know my usual rate of fatigue, and when you're within a couple % and then using NP into that number again, the difference is so negligible.