Erratic power data then smooth from half way?'

#1

First thing, my system is:-

App down loaded on a Samsung Tab A 10.1,
Tacx Bushido smart trainer, wheel on with guessed power output…<5% , NOT!
Stages 4i left hand crank as true power source, set in app.

Recently changed over to the Stages as the Bushido was losing 30/40 watts in real power!

Previos ride was erratic all the way through for power data, but the last ride became smooth just after half way?

Can I share my activites to show what’s up?

Carl.

https://app.trainerday.com/activities/621e5c9dd0f7cf1a7126e16c

https://app.trainerday.com/activities/621fae218fae13a596a2e8a0

#2

Very strange on the spiky switching to smooth. The spiky is pretty intense as well, much higher than my single sided assioma pedals. I am not sure what to say. I don’t have any good ideas. What happens when you just record your bushido?

#3

Less spiky…

https://app.trainerday.com/activities/62151fa766217873145b2bbf

Doing another ride tomorrow, we see what happens.

When would the smoothing come in, straight away after changes in the settings page?

#4

Yes this is how it should look. So it appears to be your stages power meter causing the spikey-ness. As you can imagine a single sided power meter without any internal smoothing will be more spikey although my single sided pedals are nothing like yours. I think my pedals might have some type of smoothing built in. Other software likely applies more smoothing to it so you might not notice it. Ours has no smoothing.

#5

Hmmm, well good bits and some not so good bits…

Next ride. Looked good, little bit spikey but as good as can be expected and the resistance/power followed the WO profile.

https://app.trainerday.com/activities/6222464eac0e23bf92e0dbb3

Ahhhhh, pants…what’s happened now? Next ride was way more spikey and would not follow the WO profile as I had to change my gear and cadence to get close?

https://app.trainerday.com/activities/623222bb223b95f7b03ac57d

What have I done?

Question…I have 2 sources of power output, one from the Stages crank and one from the Bushido.

How do I ensure the only ref. is the crank power meter and the resistance signal goes to the Bushido?

I have ‘ticked’ the Power Match button but this ride really felt like it was using the Busido.

Heeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeelp.

Thanks.

#6

If your PM and trainer are both connected it should always use the PM as the power source, unless there is some bug and it connects to one first and sticks to that one. That would explain it. Usually power meters are much more “jumpy” than power from a trainer. I don’t remember but did you try it without your power meter? I always want to blame wheel on trainers but I can’t say that would be the problem here.

#7

Hi Alex,
the majority of the rides have been with the Bishido as the power data source, but 2 issues have become very apparent…

  1. the Busido power output is wildly out, as stated something like 30/40 watts,
  2. when riding a workout the measured output always seemed to be higher than the target and would never equalize.

This was the reason for fitting the Stages to the turbo bike.

The below ride is with just the Busido, first 15 mins I’m changing gears then I ride in the same gear for the remainder. You can see problem 2 as above.

https://app.trainerday.com/activities/621908bae6e5f3c7ab453c41

I’ve only ridden 4 rides with the stages fitted.

Any ideas?

#8

This is interesting/strange. Do you have a bike computer? Can you do a ride like you did but record your stages on bike computer at the same time? I think this large difference between target and actual in Bushido is the source of the problem but not sure why. If you record and send me both files it might help understand.

#9

You’s thinking the same as me…I have…

  1. Garmin 500, Ant+,
  2. Polar V650, BLE.

The plan:-

Connect the App to the Bushido and my HR belt, connect the Stages to the V650.

I can ride a recovey WO on Monday, in the same low gear and cadence and record both.

Good to go?

#10

Sounds fine. Generally it seems something is wrong with your bushido because even if the power meter in the bushido is inaccurate the actual and target should basically be the same. Not this large offset. But this test might help clarify somehow. Also even with this offset and you using stages and power match I am not sure why you would get these spikes.

#11

Cheers,

if I can get it back to this ride, then I’m happy considering my system components.

https://app.trainerday.com/activities/6222464eac0e23bf92e0dbb3

Fingers crossed.

#12

Results so far…

the recovery ride went like this…
https://app.trainerday.com/activities/6241e4404a557ce1acfee439

Looked good and followed the WO as best I can expect, but…the Stages showed an average power for the first 5 min. set as 135 W. With the +35 W being the offset all the way through.

This is the reason I want to have the Stages as the ref. rather than the Bushido.

I’ll try another ride, but making sure I ‘un pair’ the Stages from anything then add it to the App. sources.