Assioma Duo + Wahoo Bolt = Low kj readings

I am using an Assioma Duo power meter with a Wahoo Bolt for recording rides outside, the data is then uploaded to Training Peaks and Wahoo element app. I notice that for a given ride the kilo joules (kj) reported on the wahoo bolt (and uploaded to the app) are significantly different when compared to the same ride uploaded to Training Peaks. Average power is the same and normalised power is always within 1-5 watts.

For example this morning I recorded a 1:57:15 ride,
Bolt average power and NP - 178W and 260W
Training peaks average power and NP - 178W and 257W
Bolt kj - 1092
Training peaks kj - 1395

My profiles, weight, FTP etc… are identical for both.

Previously I had been using a Vector S with the Wahoo Bolt and Uploading to training peaks and the kj recorded where within 10-30kj. i.e. less of a difference.

Anyone else experienced this?

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No, you’re not alone (just searched for this topic as I’m having the same issue).

Like you it’s just an issue with the display on the Bolt - when uploaded to any platform it seems to correct it. Someone on DC Rainmaker also reported the issue:

Is it still happening for you, or did you sort it out?

Plus another thread about it here:

Not sure a satisfactory conclusion was reached - some speculation about the way the Bolt records power meter zeroes as i recall.

I have the same problem.
Assioma Duo + Wahoo Bolt:
It is always the factor 0,75 on the display.
If there are 750 kjoule, then it is exactly 1000 kjoule.
I openend a ticket at wahoo support.
Lets see…
Happy Easter lockdown!
Chris

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I just emailed Wahoo about this and they asked for some screenshots and the .fit file.

Decided to do some digging on my own, and I can see that the incorrect KJ value is definitely present in the .fit file. Have seen some people claim that this is just a display issue on the BOLT itself, and that’s absolutely not true in my case. The reason that Strava and TrainingPeaks are able to arrive at an accurate KJ value is that they essentially ignore the “total_work” and “avg_power” values presented in the .fit file’s summary, and instead recalculate based off the individual power readings over the activity’s duration.

Will post back once I hear more from Wahoo – but at the very least I think I’ve conclusively proven to them that something is wrong on Wahoo’s end because the .fit file itself has a “total_work” value that is mathematically inconsistent with “avg_power” and “total_elapsed_time” for the activity.

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I’ve been encountering the same thing for quite a while. I’ll be watching this thread hoping for a resolution!

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Following

So Wahoo’s response was basically “we agree this is a problem and we’ve merged all of the customer tickets into a single issue that’s been escalated to engineering. you’ll automatically be notified if/when anything happens with it”.

Will try pinging them for follow-up, but my honest guess is that internally this is flagged as super low priority and will probably never get fixed.

Yes this has been known and reported on for years so I doubt a fix will come any time soon. There’s a Google Group for Elemnt users where people have discussed this issue.

Hey all just a heads up, this was fixed yesterday with the latest firmware release. Everything appears to work now. My last two rides are within 5 average watts and 3 kJ compared to TR and Strava.

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Oh hey, you are totally right. I just looked at today’s workout and it did indeed have the correct kj.

Very nice!

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Hi everybody,
Now the avg cadence is destroyed… what the…
I wrote to Wahoo support as follows:

Hello *,
It is a pitty!!!
The developers fixed the Kj display on the Wahoo Bolt very well.
But they destroyed the average cadence!
This field is even more important than the KJ.
The average cadence shows now 66, when it is 88. So the factor is now wrong there 0,75.
Do we have to wait now again 4 month and then something else is destroyed?
The current cadence display is displayed absolutely correctly. Only average cadence has this problem.
Can you escalate this to your manager?
I really was very happy with Wahoo and told everybody, this is better than Garmin.
But you are losing credit fast.
Thx
Christian

Maybe you all want to open up a ticket as well to get some more pressure on Wahoo?
I am working in customer support as well and very often nothing happens, because other things are more important. Manager attention and many tickets will help… :wink:

I haven’t recorded any rides since the latest firmware update, but are you certain that you have the setting for including zeros in average cadence turned off within the Elemnt companion app?

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This setting is without zero values.
It was not changed before and after the upgrade. I tested it easily during riding:
Ride easy with 88 cadence.
Display a round page with avg cadence and current cadence.
Click on round and see the very first values in the first seconds.
88 current
66 average
Many thx for your help. This is a new bug.

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Yeah I see the same thing. I’ve reported it as well.

Darn, that’s disappointing to hear it’s a new issue. We shouldn’t have to pick one or the other, but personally, I’d prefer my kjs be correct over my cadence :sweat_smile: Hopefully they fix this new cadence issue much more quickly than the power issue.

Is a rollback to older firmware possible?
Thx
Chris

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