I noticed that many group rides set classifications based on w/kg, in order to group similar abilities.
How can this be.
Say the classification is 2 w/kg, then someone weighing 100Kg will ride at twice the speed as one weighing 50Kg, if they are able to ride at 2 w/kg
Would not classifications based on ave speed be better irrespective of weight
I am referring to races on flat courses
Yes, you haven’t missed anything! I think it stems from Zwift putting quite a lot of emphasis on w/kg in the riders list and that on the old watopia loop it was a decent way of grading ability but you’re quite right in your speed analysis.
100% more power is 25% more speed. So they will be only 25% faster not twice.
But you are right. Power profiling for flat terrain races/rides should be based absolute power values, not relative. W/kg are good for very hilly or mountainous rides
Zwift provides all desired options, however it’s up to the community to choose which they use. And thus far most have gone down the route of w/kg, despite its shortcomings on many of the flat surface routes.
Average speed classifications also have their own downsides however. Given ranges are often quite large, e.g. 27 - 32, 32 - 37 or 37 - 42. Such a 5 kmph gap is a rather large one. Many may struggle. Furthermore, with no given wattage rates, on small climbs gaps may very easily form.