I would like to throw a wrinkle into this. I did a ride this past weekend where I was trying to simulate the distance and elevation gain of Leadville 100 on the Iceman Cometh course. It was for charity, so don’t tell me I’m dumb/crazy…I already know.
I was using the Everesting rules to do repeats on the small climbs (40-110 ft) to achieve the elevation gain of Columbine, Powerline, Kevins, etc. When doing to recons of all these climbs, I would do 15-30 repeats then load my ride into TrainerRoad. I would then sum the total elevation gain then divide by the number of repeats to get a good average. I then hedged each by a couple of feet and calculated how many repeats would be needed. Fast forward to the ride…
Having plenty of time on my hands to focus on my head unit (Wahoo Roam), I was noticing that it was only registering fractions of what I was expecting on some of the repeats. Some would be what I thought was correct. Others, it would only credit me for 3ft, 5ft, etc (when I was expecting 40, 60, etc.). Since the ride was for charity, I just kept going until I reached the 11k ft. However, it took me almost 2 more hours than I calculated based on my wattage pace. When the ride was done, I loaded it into TrainerRoad and Performance Analytics says I climbed 13,135ft!
Sorry for the length of the background story, but here is my question. I understand that Wahoo uses barometric altimeter. Since I was riding such short and steep climbs (some are 20%+), I can imagine that being thrown off over 20+ intervals in succession. What does TrainerRoad use for their elevation calc? GPS? It is the same GPX file from Wahoo so the base data should be the same. For what it’s worth, the mileage between the two was exactly on.
Has anyone else looked into this before I dive head first into this rabbit hole?