Listing Power Meter in Screen Name?

(J. L.) #1

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.”

(Jonathan Pait (X)) #2

I’ve been playing around with various power meters and trainers and found that there is a variety in the data output between them all. However, I think I would prefer not to know someone has a “better” meter than I. I must admit that I am envious of your Kickr. I believe that is the missing piece of my Zwift experience!

(Alan Hamilton - MRC) #3

The difference between a KICKR and a dumb trainer+PowerTap is very noticeable. I was “forced” to upgrade to a KICKR after I burned out my Kurt Kinetic while Zwifting. It was immediately apparent that I had to use a very different strategy with the KICKR if I wanted to ride nicely with others not using KICKRs, as you have explained so nicely above. In fact, I recently started riding the KICKR in the Resistance or Erg modes instead of Sim mode because it made playing with others much easier. If I’m out for a specific workout I will use my iPhone+TrainerRoad to control the KICKR. I found that if I want to ride with a group, Resistance mode is perfect, as it allows me to tune my power up and down to match the group dynamics, changing either cadence or gearing (or upping the resistance in extreme circumstances) to tune my power output. This makes drafting much easier than it is in Sim mode since the feedback loop is now local instead of going out over the Interwebs and back.

(Christian Wiedmann [X] 50) #4

I’m hoping for two changes to the Kickr experience in Zwift:

  1. I hope Wahoo adds flywheel compensation to their firmware. The unrealistic advantage when decelerating and penalty when accelerating make riding competitively with others not on Kickrs frustrating. I especially dislike that I have no jump in the sprint, which used to be one of my strengths outdoors (admittedly I don’t really have a good sprint any more, but it’s not as bad in real life as it is in Zwift).
  2. I would really like Zwift to add a mode where the Kickr’s speed is used instead of its power. This would require feeding more accurate parameters into the sim mode instead of making hills easier, but it would allow the loop to be closed locally without losing changing resistance. Unfortunately there would be some obstacles to overcome to making this work right, like making sure the two models (Zwift’s and Wahoo’s) are balanced enough to be comparable. Losing sim mode on the Kickr would also have a much greater impact on the game. I don’t know if there’s a way for an app to tell that that’s happened and set the Kickr back to sim mode (although that would ruin my Trainerroad/Zwift workouts).

(Alan Hamilton - MRC) #5

Dickson, when I use the iPhone to control the KICKR in erg mode my w/kg number being sent to Zwift is rock solid. If I set the wattage so that I am at 3.0 w/kg in Zwift it stays at 3.0 w/k +/- 0.1 w/kg. If I am in Resistance mode I can also attain a very steady w/kg number that fluctuates by only +/-0.1 or so by keeping my cadence steady, but have the advantage of being able to respond to someone going for a KOM or attacking the group.

(J. L.) #6

I need to play around with using resistance mode. When the kickr has stopped working with the game, I have jumped out and rejoined to get it back. I have been hesitant to use erg mode – I use that for Netflix – but I like the idea of using it to match a group pace.

Yeah,Dickson, game latency issues are also an interesting problem with regard to drafting and attacking. I hadn’t really spent much time worrying about it – I was hoping those problems are minimal – but you’re right, they certainly exist. You can essentially see all of these problems converge at the bottom of the hill just after green sprint line. The latency issues must certainly be part of impossibly quick shifts of the tip of the spear.

(Duane Gran [Vision]) #7

I’m having a hard time determining the utility in this proposal. I’m perfectly happy to have others know which power meter I use (a CompuTrainer, by the way) but the larger sub text here (I believe) is to create a more level playing field with information transparency.

Abandon all hope ye who enter there. It is madness just trying to get your own setup dialed in accurate let alone making a judgment call on anyone else. On the CT there are fairly elaborate protocols for comparing your outdoor riding speed on a windless day (if such a thing exists) and adjusting the drag factor and weight to get virtual rides dialed in. It can be done and I’ve personally gotten it within 5% but if we unpack the russian dolls it looks like this:

  • People who ride bikes
    • and ride them on a trainer
    • and use a power meter
      • and ride on Zwift
      • and know (or care enough) to finely calibrate said power meters
        • in order to get their road riding and virtual riding in harmony

This is easily in the category of stuff-that-is-interesting-but-not-important for Zwift. For one more anecdote, I’ll give you an example of something RacerMate is doing. They have some Time Trail software that enforces getting your CT all calibrated and ready to do a 40km TT. You would have to make an exceptional effort to cheat the system and when you are done you upload your results to a worldwide leader board. It should be bike-nerd heaven, but they have just seven people on this leader board. Making an accountable and trustworthy virtual competition space is hardly the path of riches and fame.

(Ron Skinner) #8

I for one would love to see the rider system displayed, be it a standard resistance trainer, a Kicker, Computrainer, or standalone power meter. In fact I would suggest parallel worlds, the exact same but one for smart trainers like Kicker and Computrainers, and possibly also real power meters, and another for plain resistance units. This would make the experience more comparable, it sucks to be chasing a jersey to guess that the holder is not playing with the same rules you are. I would like to feel that the power numbers and watts/ kg are on a level game field.