hi all, i just had the same issue as above. i used Zwift to recalibrate (i’ve go a Kickr Snap) and following that, the displayed power dropped significantly (felt like i was riding ~300W and it was displaying as low 200’s.) i tried a few different options, in the end i unplugged the Kickr for few mins, then plugged back in and tried the wahoo advanced spin down (basic spin down wasn’t fixing problem even after tightening and getting spindown time down to about 18s). i kept tightening until it got to ~16seconds and now the power is showing OK on Zwift.
Thank you Timothy for starting this conversation. I also just cleaned my bike and replaced back tire a week ago and have been fighting to get through my workouts ever since. It wasnt they were easy but like the comments have replied… a little like MUD!
It’s hard to put your finger on. I have re calibrated with Zwift and Wahoo and it has not adjusted the problem.It’s very frustrating. I have spent so much time getting it just right and have enjoyed Swift with friends. But now I can’t even stay close to them on a ride.
It has been very discouraging to have dropped so much in my ability to attain the same level of power as I did prior to the tire changing ect.
I am going to try the advanced spin down. I have a Kickr Snap.
I am hoping it helps. The support from Wahoo is not really there at the moment.
At least I know I am not alone!!
Seems like everyone who has this problem has a Kickr Snap. I went for nearly a year, working several times a week, to build my FTP to what I thought was almost 350w. It took a lot of work. I rode on Zwift and did hard workouts at least 3 times per week. I completed the whole Zwift Academy, and did the little races and stuff. When my trainer recalibrated it called into question all of that work, and made me question the accuracy of anything that happens on Zwift.
Having the exact same issue now. Power is 20-25% off relative to what I’m producing on board my wife’s Hammer and what it was just a week ago before I attempted to re-calibrate in game. It’s now super unstable after sprints and seeing power decreases when out of the saddle.
I might try to return mine for a wheel off trainer. I bought my Snap just under a year ago at REI.
FWIW - I have never used a real power meter. According to the new training program I’m using, my current FTP is 268. I wondered how accurate that might be so I looked back at my Strava for a segment that I did at pretty close to full gas for around 20 mins. Something that represents the closest thing I’ve ever done to an outdoor FTP test. It’s a flat 7 miles on our bike path that involves some little twists and turns. I did 24.2 mph average. The segment took 17:27. That’s my PR. Strava estimated 240 watts. So, if you figure coasting around the turns and up and down bridges, I would say 260-270 FTP sounds about right.
What I guess I’m saying is that I was probably nowhere near the 350 FTP I thought I had.
I have found the same issues with keeping up competitively on Zwift as my power records at a lower level than it should. It doesn’t affect the quality of my workouts as much as it does the overall joy I might be able get out of Zwift. Comparing to peers on Strava my avg watts for a ride I will be at 185 whereas those I ride with outdoors are at 270. I understand that they could be going faster than me but that differential is not realistic.
tldnr: kickr snap power is rubbish, the spindown is a joke. You can ride with to low power numbers with the spindown, or too high without.
Hey. This is a while ago, but I comment anyway. I ride with an extra training wheel as well. always calibrated my kickr snap every single time as said in the manual (and which is super annoying). With 10 m warmup and making sure spindown time is between 10 and 15 seconds. and had over time risen my ftp from about 180 to 220. I just thought I maybe don’t have the genes for cycling, running being my first sport anyway.
A few weeks ago I invested in a new bike with a powermeter and it turns out, I can do a 15 mins climb averaging 300 watts, and more than one per ride. (Which matches roughly with calculated power on strava, but I thought strava just wants to stroke my ego so I buy premium). While 270 watts is my max 5 min effort on the snap and then I’m done.
New bike has thru axle, and I won’t buy the upgrade kit from wahoo. So I can’t directly compare the power meter with the kickr snap.
They don’t see money from me again, next trainer is a tacx
Any chance you tried putting the old tire back on? I’ve also just changed my tire and I’m having a horrible experience with the new one. Can barely pedal. I’ve tried recalibrating etc, and I think the only thing left to do is put the old tire back on and see if it goes back to normal.
My Snap read low power for almost 2 years, I’m not a high power rider in the first place. I think it is essential to do an advanced Spindown when you take delivery as you don’t know what has happened between manufacture and delivery. Then you need to do one every few months as it gradually changes over time - so why the heck is it hidden!!!
Once I started pumping the tyre harder (over 100psi) and being sure my spindown was under 15 seconds and doing a proper warmup before the spindowns it came right. It’s like the trainer calibration moves over time and the only thing which can fix it is the advances Spindown which adjusts the braking factor. Finally it felt spot on, but I only knew it was working right when I compared my effort and power to a Kickr Core (I guess they could both be out but I don’t think so),
I wish I had an independent power meter to compare the Snap to but I didn’t, I thought I was just useless!
One way I found that gave me a clue something wasn’t right was to pedal at low power. If I was still putting in an OK but low effort and I stopped in Zwift then something had to be out. Only the advanced spindown appears to fix that. I found the standard spindown only adjusted the bias of how easy/hard it was to go uphill or downhill, ie easy up and hard to go down or in my case almost impossible to generate power going up but I could generate twice as much with no effort going down.
Not sure if that helps, but that’s my experience.
When I bought the Snap I felt the power was too high. Prior to lockdown I was using the Wattbikes at the gym. Since the firmware update I feel the Snap is more realistic and in line with my Wattbike power. I feel satisfied now more then ever with the Snap.
The issue is the consistency. I guess I wouldn’t really care if the Snap was inaccurate (low or high), if the power was consistent so I could actually train to consistent numbers. Instead, the power is all over the place. Erg mode is unusable as the tension ramps up so high I can barely move. I climb steep climb hills here locally, and tension in erg is worse than anything gravity has to throw at me.
Anyway, FWIW I’m still using the Snap, just with TR and not Zwift anymore. I used it for an hour this morning actually, but, in the first 5 mins I noticed that 300w felt waaay too easy. I did a spin down in TR. Suddenly 250 felt like 350 did previously. It’s frustrating but I try not to think about it too much. One of these days I’ll spring for a wheel off trainer that I imagine has none of these issues.
Timothy, here’s my 2 cents. The FTP of 350W seems extraordinarily high, especially for someone as light as you. I ride with a Garmin power meter for my outdoor rides and have around a 220W FTP for outdoor riding. I weigh around 215lbs, so I’m pretty heavy for a cyclist, but I typically average in the 18mph range for a 20mi ride if it’s not too hilly. Im sure your FTP is still higher than mine, but it wouldn’t need to be that much higher in order to produce the performance differences between us since you’re significantly lighter than me. (i.e., it takes less watts to move you than my fat butt…lol)
But, I have the same issue on my snap. When I hop on my kicker snap, it’s like you said, riding through mud. Especially after I calibrate it. I would estimate that 130W on my Snap feels about like 200W outside. Using ERG mode just makes it even worse. I usually end up turning off the ERG because it’s just torture. Interestingly, when I calibrate the Snap with my carbon rims installed and then switch them out for my heavier aluminum rims (without recalibrating the snap), the snap feels closer to outdoor riding (though still harder). Obviously, aerodynamics aren’t at play here since it’s stationary, but perhaps since it takes less energy to slow the carbon rims down (since they’re lighter and have less inertia), when I swap them out for the heavier aluminum rims, the higher inertia of the heavier rims keeps them spinning longer and results in less fatigue for me? Who knows. But I will concur that the snap’s wattage seems consistently low compared to my power meter, and it’s worse after recalibrating it.
I weigh 175. I’m not that light.
Yeah, I’ve since discovered that my FTP was way off. After recalibrating and taking an FTP test on trainer road my most recent FTP was 296. I also recently got a 4iiii power meter and have used it on 2 rides. Both rides were about an hour on hilly terrain and my avg power was 205 and 211, and my NP around 250. So, I would guess that 295 is correct. I no longer think the Snap is inaccurate.
But… like you said, the snap has a massive prob w/ erg mode and tension. No need to repeat you. I have the exact same probs. Erg is useless, and unless I manually override the tension it’s unuseable. When I’m using Trainerroad, if I turn up the tension to 50 percent, I have to stand on the pedals to keep them going as if I’m climbing a 20 percent grade, yet my watts will show low 100s. If I stand and pedal outside with a real PM and put out that kind of effort then I’ll see 600-700w+ until I overcome the inertia. My Snap will read 0-100 the whole time.
Turn the resistance down and the watts suddenly shoot up for half the effort. That works ok for about a minute or two, until my cadence gets ridiculous and I’m spinning 130+ rpm to maintain 300w.
The Snap is an aggravating piece of equip.
Same issue for me! I changed my tire and the second time on the trainer my power would increase then slowly dropped to zero. Did a bunch of spindown plus factory spindown and few adjustment with Wahoo support and now it doesn’t drop to zero watts but I can barely pedal during warm up:sweat_smile:. There was some slippage with the tire so I turned the knob a bit more but can’t turn it up 5-6 turns either lol. It is so frustrating… Now I think I might have to change it
and first excuse my bad english.
I had the same problem a few days ago. At first i thought i had a cold and no more strength.
After a few days’ break i tried again. In my GA1 area I couldn’t drive for 30 minutes without my pulse going through the roof top.
I did the following steps and fixed my problem:
Started the Wahoo App (iOS) and removed the Wahoo KICKR SNAP. Then reconnected it again.
Started a workout with the wahoo App (10 minutes to warm up the device). I noticed that the settings “Level”, “Resistance”, “ERG” & “SIM” on the last page (swipe to the left in workput interface) have an influence on the resistance when driving without changing the values.
I pressed the “Resistance” tab - pedaling was very easy here (Driving on “Level” tap was quite tough.) and drove 10 minutes and closed the app.
I opened the App again and did the normal spin down in about 19 seconds (34 degrees). Closed the App.
I deactivated Bluetooth on the mobile phone and started SWIFT. Everything was as it should be again.
I hope this helps you.
I am having the exact problem now with my new Kickr Snap
I have the same problem my spin down time is 16 but Zwift cannot accurately register my power output and now it’s so difficult to get my speed up while riding
After you do a spindown calibration, does the Wahoo App accurately register power from your Kickr Snap?