I am sure versions of this have been discussed (and feature changes suggested), but with the increasing proliferation of races and fast rides – and people casting sidelong glances at notable performances – I thought I would bring this up: Should we be noting somehow on our screen name which trainer we are using? Like appending “-Kickr” or “PT” or whatever we use for our profile name?
I did a quick hot lap comparison of the data and RPE between my Kickr and a PT on a trainer. Any accuracy differences aside – more on that later – the methods and strategies for getting the most out of my power on each of the devices is divergent enough to make for a different experience, one that surely affects a race outcome and group ride dynamics. On the kickr, you can quickly use the bite of the hills to accelerate – if you’re a punchy, high torque, lower crank velocity rider, it’s a major advantage that goes beyond shifting to make it harder on a conventional trainer. You can ramp up your power in advance of a climb, and punch it as the incline kicks in. It’s closer to reality, but it also gives you a little credit for momentum as it spikes the power when the resistance changes. Even if you are spending your time solo in the wind pushing the pace of a group, creating these repeated gaps using a kickr would likely exhaust anyone trying to sit within the group on a PT/trainier, even with comparable capabilities. With this ability to hit the hills, you can shift your “area under the curve” to a high normalized ride with a lower average, particularly if you are surfing back into the group for the flats. Could I drop a doppelganger of myself on a powertap/trainer using a kickr? Yes. Easily.
In addition to this, the consistency of the power is also notable. The power curve is smooth and consistent on the kickr, unlike the sawtoothed, variable output on the PT (some of this is, I gather, an artifact of the sampling and the reporting at the device level). While this might have little effect on the actual average output, it does affect a pacing strategy if one tries to hit a certain pace as the speed ebbs and flows due to the virtual terrain.
Accuracy, as many have pointed out, is another reason to note which meter is being used. I have spent far too much time attempting to make my Kickr as accurate as possible (I finally settled on 1.3.8 beta firmware and calibrating it after about 5 to 10 minutes at 200w or so). It’s close, but I would guess (and without installing a SRM or Quarq I won’t know ) it’s still running a little over – I have nothing to go with but years of experience of riding with power (and using HR to baseline it is far too error prone). For an hour, it’s maybe not wildly different. It’s hard to say, but I have, for instance, not exceeded an MMP record from outside (though doing close to it is suspect at my current fitness level). For a longer ride, I’d guess it’s in the 5% range. Again, this is wildly speculative, but still worth noting, since this experience does not seem atypical. I considered adding ~10 pounds to my real weight in my profile, but thought better of it.
So, yeah, long rambing post, but wanted to put it out there so that we could perhaps quickly classify the performances among those of us that are likely attempting to get around the island as quickly as possible. It would be certainly useful to know not just in “race” situations, but also when attempting to levelset the pace on a fast ride. Who knows, maybe it’d turn into: “Kickrs pace the flats, PTs and others pace the hills – and downhills.”