Low Power Readings on Climbs / Wahoo Trainer

(Aaron Terrazas (Revs)) #1

I’m using a Wahoo Kickr Snap trainer with speed and cadence sensors. Power seems to be fine until I hit a climb, then the power drops. I start putting down power and I am barely hitting 200-230 watts, but it feels like I am 300-350+ watts. When I stood up, the watts dropped even more, so that tells me something is up. 

Any ideas what could be the issue?

(Nathan Gonzales - ATX) #2

I’m having the same issue only when i hit the climbs i’m going all out and barely hitting 100 watts and going like 2-4mph which doesn’t make any sense since I’m clearly putting in the work that should result in more watts and more speed. I’ve used a Cyclops dumb trainer and the Wahoo Kickr on Zwift and on both my overall times, power, watts, segments etc etc …have all gone down since I got the Kickr Snap 2 days ago. Something isn’t right but I’ve gone through all the basic troubleshooting and checking of things and I can’t figure out what the issue is so I’m really hoping someone chimes in on this with some ideas or suggestions of things to try to fix this. It would be much appreciated.

(Doug Roland TV5) #3

Same here on the snap.  Have have the origins kickr as well and that works great.  The snap looks like it’s only picking up half the power on hills or any incline.  I’ve played with the tension on the wheel as well as the degree of variance Zwift sends to it(settings in game).  Anyone? Thanks.  

(Liam Gregorious) #4

I have a similar issue with the Snap.  The trainer difficulty is set to the default of medium.  The resistance increases as expected when I hit a climb but even though I feel like I’m putting in much more effort the wattage seems to drop most of the time (along with my speed).

(Aaron Terrazas (Revs)) #5

I have not heard back from anybody on this issue. Let me send a support ticket to Zwift directly and see if Wahoo has a firmware update for the Kickr. 

I ended up using my Stages Power Meter for power and the Kickr just for the tension, but that doesn’t solve the drop in power on climbs issue.

(Aaron Terrazas (Revs)) #6

I am on Kickr Firmware 2.0.19. If you have the Wahoo Utility app, connect it to the Snap and it will prompt you to upgrade your firmware.


I am going to see if this fixes the issue. I just submitted a ticket to Zwift, waiting to hear back.

I also spoke with Wahoo and they have not heard of the issue until now. I’ll let  you all know how it goes.

(Bryan Bleak) #7

I have the same issue with my new Snap. I am on 2.0.28 (which I think it newer then 2.0.19). So the latest firmware version did not make a change. Please keep us in the loop when you hear back.

(Simon Ker Fauxpro.cc) #8

Same issue here… The harder the effort, the weaker i seem to get FW: 2.0.28 

(Aaron Terrazas (Revs)) #9

Still no response from Zwift…

(Simon Ker Fauxpro.cc) #10

Do you think it is a Zwift issue rather than a Kickr one? I only started using the snap today so i’m not completely clued up on it but the Kickr app also seems to show low power (I would assume that the kickr knows how much resistance it is applying vs how much force you are regardless of which app is controlling the resistance - I could very well be wrong about that though)

(Aaron Terrazas (Revs)) #11

Simon I am thinking its probably a combination of both, who knows.

My wife just used Wahoo / Zwift and the power seemed to be ok on the hills now. It seems to now keep her power on climbs and we even saw power increases when standing out of the saddle (finally).

Here is what I have done.

  1. Upgraded the Wahoo Firmware to 2.0.28 
  2. Did a spindown / reset of the Wahoo Kickr
  3. re-synced the Wahoo Kickr with Zwift




(Simon Ker Fauxpro.cc) #12

Spoke to support at Kickr and they asked how I had done calibration on the kickr (android app) - they suggested using an ios device…

“If you are able to use the iPad (gen 3 or newer) you will be able to use the Wahoo Fitness app to perform an Advanced Spindown on the Snap. This sets the internal brake on your Snap and only has to be done once. After doing the advanced spindown you can just do the normal spindown on your Android device each time you ride”

Anyone tried an advanced spindown using iOS i will have to bring my iPad home from work tomorrow before I can try it?

(Aaron Terrazas (Revs)) #13

Just the initial spindown on my iphone with the utility app. the advanced can be done using the fitness app and takes 10 minutes of riding. 

The last session seemed to work for my wife, so if it doesn’t work for me, I’ll try the advanced spin down. 

(Liam Gregorious) #14

Interesting update.  I also have only done the spindown on android.  Will use the ipad tonight instead and will let you know how I get on.

It’s a bit frustrating that the Wahoo site makes no mention of an advanced spindown so if you don’t use an iOS app you don’t know it exists!

(Bryan Bleak) #15

When I first got my Snap (1.5 weeks ago) I did the advanced spindown with my iPhone 6s. I still had the issue when I first road on Zwift (1 week ago) so I’m not sure that is the issue. I’ll do the advanced spindown again though.

(Bryan Bleak) #16

To clarify my previous post - I did not do an “advanced spindown” when I first got my Snap. I did an “initial spindown”. Not sure how they are different. Today I did the advanced spindown (took 3 minutes) and then road Watopia. Worked as expected. So perhaps the advanced spindown can fix the issue. Used my iphone for this. Good luck.

(Aaron Terrazas (Revs)) #17


Great to know. I am going to try it tomorrow now that I have done everything. I did sent the .txt log file to Zwift as they asked so that they can see what was going on during that ride with the power dropping out. Ticket with them is still open.

I’ll keep everybody posted.

(Liam Gregorious) #18


I’m pleased to say that I did an advanced spindown last night which set the brake strength to 1.64 (whatever that means!).

I then rode on Zwift and all was great.  My power output was higher as expected on the climbs.

So for me, at least, the advanced spindown sorted the issue.  If only Wahoo would make this feature available on android!

(Simon Ker Fauxpro.cc) #19

Sounds positive… Only problem is that I don’t have access to an ios device new enough (apparently ipad gen3 doesn’t support the app) oh well, i’m sure i’ll find someone that can lend me their phone at some point

(Jerry Weiss) #20

I have the same problem and the app doesn’t work on my ipad gen3 (it just crashes when I open it).  I did a cold (no warm up) spindown calibration yesterday with my android phone and rode Zwift today and it seemed like the power was right (I also turned down the trainer difficulty to about 20%).  After 40minutes of riding I did another Kickr Snap spindown calibration and the power readings were immediately lower than my perceived effort.  Going to try the advanced spindown (borrowing a newer iPad).