In the case of power meters, W/kg is determined by dividing the power reading by the rider’s weight, so no, that value does not include the weight of the bike. There’s no reason to.Kender said:Does watts/Kg take into account the weight of the bike and biddons onboard?
The weight of the bike does come into play when calculating power from VAM, that is, the speed up a climb of known gradient and distance, because for any given power the cyclist puts out, he must raise the weight of both his body and the bike up that vertical distance. The VAM formula is supposed to take this into account, not perfectly, because it’s not perfect, but close enough. If some breakthrough occurred that allowed manufacture of ultra-light bikes that weighed less than a kilo, in principle the VAM formula might have to be tweaked a little. Not a lot, though, because as it is, the bike’s weight is relatively small compared to the rider’s weight. Online bike calculators allow you to make somewhat more precise estimates of power taking into account the weight of the bike, among other factors.
Sure, the rider’s weight will fluctuate, but that doesn’t affect power calculations that much. Using that 414 W value for Froome (uncorrected), if his weight is 68 +/- 1 kg, his power output is 6.09 +/- 0.09 kg. But it will tend towards an equilibrium value, because any more results from drinking more than the body can immediately absorb, and any less results in dehydration and thirst. A rider will feel comfortable at some normally hydrated level.carton said:But the riders would be taking in at least 1 bidon of fluid adding 700 grams in rider weight an hour. And sweating out a similar amount. Plus likely taking a piss at some point. So on any given day rider weight should fluctuate at least +/- 1kg (probably much more on a hot day). Since dehydration could absolutely kill you (or at the very least put a serious damper on performance), my guess is that you'll be aiming at having taken in at least 1L (1kg) extra of fluids vs. training on a balmy day.
In any case, this is why VAM—despite being affected by wind and other conditions--is useful, since it’s proportional to power/weight. It doesn’t matter what a rider’s weight is, so two riders of different weights riding under the same conditions will have essentially the same W/kg values if they climb at the same speed.
And the Angels are hot! And Albert is putting out Froome-like numbers!BYOP88 said:I'm way too lazy and it's baseball season.