I’m new to smart trainers and I’ve been I’ve been enjoying both TR and Zwift since I bought a KICKR (my first trainer) a couple of weeks ago. But curiosity got the better of me and I decided to compare the KICKR with my trusty power2max Type S and I found that it’s consistently reading high.
For example, here’s a Goddard -4 I did the other day in ERG mode: DC Rainmaker Analyzer
The KICKR seems to track the p2m quite well, but is consistently around 10 W high.
And a chilled out Zwift session from today for some recovery (ignore the gap in the middle when ELEMNT paused itself): DC Rainmaker Analyzer
While the difference isn’t as obvious here (more like 5 W), but the KICKR’s readings are quite spiky and erratic in this case.
When I look at DCR’s analysis, it looks somewhat better behaved: DC Rainmaker Analyzer
Is this normal for a KICKR (or any smart trainer)? Am I just being too fussy?
P.S. I’m using the latest firmware (v4.2.1) on the KICKR.
Your Zwift/sim-mode workout seems fine to me, 5W isnt that much.
When I look at the TR workout, I see a couple of interesting things. Seems like PM and Kickr reads spot on between 4min and 8min (marked with yellow). It also seems like there maybe some power smoothing turned on in Wahoo app (marked with red).
I have had good success with doing a factory spindown post workout (when trainer is warm), my Kickr now reads very close to my PMs, but i still see som drift during a workout, most within the first 30-40 mins.
I would try a factory spindown and test more to see if you can find some kind of pattern. If you can it would also be great to test with an other PM too.
This one seems a bit better behaved; the difference is consistently around 6 W this time, which seems more reasonable (ignoring the ITL bit at the beginning).
But the recoveries still look pretty weird. We’re looking at 10 W or so again, and the power from TR is clearly smoother… almost suspiciously smooth. I don’t have any kind of smoothing switched on in the Wahoo app, so I don’t know what’s going on there.
My plan for tomorrow’s session is to swap to a different power meter (power2max NGeco with 1% accuracy) and then do a factory spindown as daniebr suggested. Sadly I don’t have any pedals I can use at the same time.
The power from the KICKR is higher, and suspiciously smooth. @daniebr Is this something you’ve seen in your tests? Maybe an effect that’s only present at low power in ERG mode?
I guess I don’t care that much if it’s only happening during recovery…
My Kickr readings is smoother than my PM readings, but I dont see any difference in smoothing during recoveries. This is my newest set, as usual my Kickr reads a bit high in the start, accuracy seems better during intervals(high power) than during recoveries: https://analyze.dcrainmaker.com/#/public/4bfed404-3f71-488a-6095-63e33b69b2d2
I’m also experiencing a strange issue. Brand new V5, up to date firmware. Last night’s threshold intervals, my stages Left side PM is consistently higher(I expected this and not surprised). For the most part they both track pretty well together, but at the start of the intervals it takes the power reported from the Kickr about 3 minutes to ‘ramp up’. Ultimately I’m not too concerned about it as I use the stages as my power source.
This time I was using a brand-new NGeco power meter with 1% accuracy.
Starts off bang-on, but by the end of the session the KICKR was reading 6 W lower. Not sure what to think now. I’ll try tomorrow’s ERG mode workout with the same power meter and report back.
I’ve tested my new V5 with a long steady state effort against my old set of Powertap P1 pedals and new Magene dual sided unit: DC Rainmaker Analyzer
Ignoring the efforts at the end where the Magene is looking problematic (there’s a thread about that elsewhere) I took a look at the the first 30 minutes (after the first 10, so 10-40m) and the last 30m before messing about at the end. Looks like it breaks down like so:
Kickr is 2.5% higher than P1 on average at the start, 1.9% higher at the end, which seems like a wash.
Is anybody seeing drift on long sessions, or is it mostly during shorter more intense intervals?
Yep, I went back down at 150-200 W. I can only assume this allowed it to cool down, and that it’s the internal temperature of the KICKR that causes the issue.
Glad I’m not a pro with an FTP of a bazillion watts…
Make sure you let them know that there are a few people having this issue - when I briefly mentioned it to wahoo support they said that they hadn’t had any reports of similar issues…
