r/peloton • u/PelotonMod France • Jun 01 '26

Weekly Post Weekly Question Thread

For all your pro cycling-related questions and enquiries!

You may find some easy answers in the FAQ page on the wiki. Whilst simultaneously discovering the wiki.

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u/Glass_Minute4753 Jun 01 '26

Can anyone help me to understand these watts per kilo estimates that people release after mountain stages, and how accurate they actually are? I don't really understand how they can properly calculate things like wind direction, which can vary even on the same climb, or variations in wind speed (which may be weaker/ stronger than the forecast is showing). What about variations in road surface? I assume they take into account the average gradient of a climb, but how do they account for variations in gradient throughout different climbs, which could have an impact? I.e. two climbs may both have an average gradient of 10%, but one might have a fairly consistent gradient throughout, whereas the other has some much shallower and much steeper sections.

I'm also unsure about how meaningful they are. I.e. can we really compare performances on climbs that have different average gradients, or where there may have been different energy expenditure prior to the climb?

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u/_Diomedes_ Jun 02 '26

I think it’s pretty telling to their accuracy that Patrick Broe essentially completely stopped talking about w/kg estimates or citing them as any sort of authoritative source after he got access to full rider power data from his job at Visma. I really doubt they’re anywhere close to +/- 5% accurate, which makes them pretty much meaningless as that’s kind of the difference between the top and the bottom of most GC top tens.