FTP 54 difference - SF vs. TR

seems reasonable… Some podcast I recently heard that a combination of day-to-day differences in your physical readiness, along with power meter accuracy can result in FTP estimates being within 10W of actual. At a 250W FTP that 10W is 4% error, or +/- 2%. I guess that seems reasonable, and makes me wonder what if I test on a “best” day and then train on a “good” day. Put in that context, and having done mostly outside training recently it makes me wonder about using erg in the future…

@bbarrera erg mode is great. It does create an extra layer of training/equipment/tech learning requirements, as I’m just now finding out

I started with erg and used it for a few years now, and it does change the dynamic of riding a bike. I’ve moved to outside training since February, and played around with resistance (standard) mode a little the few times I was forced to train inside. Rethinking my position on erg, for several reasons…

I’ve gone off ERG recently, it probably doesn’t help that I’m riding a KICKR SNAP and my trainer tyre is getting a little long in the tooth but I just don’t feel it does what I want it to. Generally I can hit my marks better in resistance.

I do like ERG for zoning out and thinking about something else on z2 rides though.

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@mi-xc, 16w difference at a target power around 400w seems a tad bit high (4%) but may not be entirely out of the ballpark given drive drain loses are commonly around 2-3%. Therefore, I think what you’re seeing is that your pedals and trainer are consistently 4% different. 4% of 150w is 6w whereas 4% of 400w is the 16w you mention in your post. Looking at your plot I’d say that everything is tracking, albeit with up to 4% difference. Again, noting drive train loses, I think that’s pretty good. Just my two cents.