Bit of background. I’ve been using a Kickr Core with Zwift from Jan '21 until late July without any issues. Then during a particular group ride i started getting what seemed like power spikes, it would correct itself and then the power spikes would return.
Since that ride the power spikes have gradually increased to where they happen every single ride. There doesn’t appear to be pattern to it, it can happen on flat, ascents & descents. It’s never right at the start of a ride but again no pattern, my last two rides it started around the 14 minute mark and then today’s ride around the 21 minute mark. It can last a few seconds to a few minutes.
I’ve upgraded/downgraded the Kickr firmware. Done countless Wahoo app normal spindowns and a factory spindown. Reset the bluetooth on my Macbook, ensured my phone (which is the only other device i have next to me during Zwift) is not connected to the trainer.
Nothing in my set-up has changed at all so it’s difficult to pinpoint anything. It’s now driving me nuts and i’ve obviously had to stop racing as well.
If i could i would attach my latest Zwift fit file but it doesn’t look like i can. I stopped the ride at the exact point the spike happened.
For me it looks like loosing draft in group rides. I have the same issue, sometimes with Coco 350W isn’t enought to stay in blob. No matter of platform, always in big group ride or blob.
I have a little more info on this. Logged a support call with Wahoo who came back saying that it looks like the Kickr is connected to another device in the background. The only other device in the vicinity of the trainer, other than the Macbook, is my phone and bluetooth is always switched off unless im using it.
I powered down my phone and started another Zwift session on the Macbook. All good for the first 30 mins or so and then it begins to feel like the resistance has gone, I can’t feel the little inclines anymore until gradually some power spikes start appearing.
I managed to borrow an iPad, so after powering down the Mac i started another session (same pace partner course as before) this time it’s perfect, everything felt as it should for the whole duration. I even powered up my phone and had the companion app running with no issues.
So it looks like something is happening between the Macbook/Kickr/Zwift that’s causing this issue. I’ve restarted the Macbook, deleted the bluetooth preference list. But i’m really out of ideas on what to try next.
More bad news…Experienced the same issue with the iPad via bluetooth. Invested in an ANT+ dongle (i have it right next to the trainer) and still no luck. Couple of screenshots of the log file when loaded to Zwiftalizer:
I’ve been having this exact same issue recently between my Kickr Core and iPad Pro. I recently replaced an older, no-longer-supported iPad with my newer iPad Pro. I don’t think the issue is with either the Kickr or the iPad as both work fine with other applications such as TrainerRoad. When the spikes occur, they essentially force me to stop the ride as they are too steep/difficult to power through. This issue is rendering Zwift unusable. I checked my Bluetooth connection and it appears to be fine. I don’t have any other apps or devices using Bluetooth in the area.
Same issue with me, since the beginning of time… which for me was about a year ago. But the spikes for my power levels seem much more frequent and at a higher scale.
I don’t notice any big problem areas on zwiftalizer.
A couple of bluetooth disconnects about 3/4 of the way in the ride, but that doesn’t come anywhere close to lining up with the power spikes (and drops).
There might be a relationship with cadence changes, but I usually keep my cadence pretty steady. Below are a few examples from recent rides. All were workouts with ERG mode on. Zwift setting is to show 3-second average power.
And the power spikes and drops aren’t related to terrain changes or elevation.
I calibrate my trainer once every month or so.
My trainer is a Magene T300 smart trainer coupled to my computer (Macbook) via bluetooth. I also run the companion app on my iPhone at the same time. My Macbook is also connected to a flat screen by an HDMI cable. Everything is running on the same dedicated WIFI router in the pain cave.
Do you have ERG smoothing on which is configured in the Wahoo app? The 2nd graph with power suggests it is on but worth checking but half way through it goes bonkers.
edit: do you have a head unit you can also monitor power?
yes, for all workouts i run ERG. i believe it’s controlled by zwift, rather than my trainer.
right… same thing i noticed is that at the halfway point it goes nuts.
when my trainer is connected by bluetooth to the zwift app, i can’t connect to it with any other device. i have tried to connect to it with my phone, but it seems not possible.
Wahoo have an additional setting for ERG smoothing specifically for workouts in addition to what Zwift does. Here’s a vid that explains it - so just an fyi about the function.
Try joining Wahoo/RGT (free for first 2 weeks) and do a workout and see if you get similar result.
Do you know anyone with a Wahoo/Garmin head unit you could use - dual recording a Zwift event and viewing the different graphs could help isolate where problem is too.
I do have a Wahoo head unit (an Elemnt Roam) that I can try connecting. My guess is that it will run into the same bluetooth restriction, but it’s worth a try.
And… yeah… RGT… more and more guys here are using it. I’ve been meaning to give it a go. It looks pretty cool.
I will also check on my smart trainer (not a Wahoo) to see if it has a power smoothing setting as well. I seem to recall that there’s something like that on there, along with a “target power” setting that I can play with.
probably because this thread is for “Wahoo Kickr”…
so actually it was my bad, originally, to post my “me too” on this thread. but i thought that maybe the issue could be related to zwift, rather than the smart trainer, since i was seeing a similar kind of behavior.
your feedback, nonetheless, is helpful. so i didn’t take it as dribble.
