Best way to compare smart trainer to power meter

supermurph09

To simplify my training over winter I am planning on using my smart trainer only to record the power data, previously I have used my power meter when doing my indoor training. Now I have a dedicated winter bike I'm moving the power meter to that, on which it will stay so I don't have to swap between bikes. Admittedly this is only a minor inconvenience but if I can compare the trainer to the power meter and establish what the variances are I'd be happier with that setup.

So what I want to do is figure the best way to run both (trainer and PM) so that I can compare some of the intervals.

My thinking would be to ensure I do the same warm up each time on the trainer, same tyre pressure etc and then off I go. I'm pretty experienced when it comes to indoor training mostly creating my own sessions in training peaks and syncing to my Wahoo but I have chosen to go with Sufferfest this time around. I do have a good sense of what different powers feel like.

Could I do the 4DP test on Sufferfest using my trainer as the power source but also record the workout via my wahoo and then compare the intervals? Given that the 4DP has a good range of intervals this seems sensible.

fenix

Can you use the free Zwift Trial to use their power levels ? You just enter what turbo you have and then it will give you a calculated power ?

napoleond

Hi mate, what I did to get confidence in my kickr was record rides on zwift (or TR or whatever) using the power from the kickr and record the output from my quarq on the Garmin. I found that they were pretty damned close (and consistently so) with each other.

dannbodge

https://www.dcrainmaker.com/2018/12/how ... ssues.html

Stick the bike with the PM on the turbo and follow the link above (pretty sure that's what you asked) but yes you can.
You can then apply a correction factor to the Power meter so they both match.

pblakeney

NapoleonD wrote:

Hi mate, what I did to get confidence in my kickr was record rides on zwift (or TR or whatever) using the power from the kickr and record the output from my quarq on the Garmin. I found that they were pretty damned close (and consistently so) with each other.

This.
How do you compare figures? You simply compare figures.
And Jason says hello.

supermurph09

Thanks guys, I’ll review the suggestions.

rollemynot

PBlakeney wrote:

NapoleonD wrote:

Hi mate, what I did to get confidence in my kickr was record rides on zwift (or TR or whatever) using the power from the kickr and record the output from my quarq on the Garmin. I found that they were pretty damned close (and consistently so) with each other.

This.
How do you compare figures? You simply compare figures.

Me agree also

supermurph09

As you’d probably expect the turbo tends to be a bit over but can often be on the money. I’m doing lots of short intervals at the moment but what I will say is that things look consistent.

I do my 6-7 minute warm up, calibrate then start, same PSI etc. Looking forward to doing some more steady state stuff to compare but happy with results so far.

StillGoing

Supermurph09 wrote:

As you’d probably expect the turbo tends to be a bit over but can often be on the money. I’m doing lots of short intervals at the moment but what I will say is that things look consistent.

I do my 6-7 minute warm up, calibrate then start, same PSI etc. Looking forward to doing some more steady state stuff to compare but happy with results so far.

Really? As the turbo is recording measurement further along the chain line than pedal or spider based power meters, it should be recording lower, even if just slightly. The further you are away from the appliance of the torque in recording the watts, the higher the loss in power. Much like an engines BHP is stronger at the flywheel than the wheel.

It doesn't really matter as long as you train to the numbers you're given. You might record 200 watts on your device, but 210 watts on someone else's.

slowmart

philthy3 wrote:

Supermurph09 wrote:

As you’d probably expect the turbo tends to be a bit over but can often be on the money. I’m doing lots of short intervals at the moment but what I will say is that things look consistent.

I do my 6-7 minute warm up, calibrate then start, same PSI etc. Looking forward to doing some more steady state stuff to compare but happy with results so far.

Really? As the turbo is recording measurement further along the chain line than pedal or spider based power meters, it should be recording lower, even if just slightly. The further you are away from the appliance of the torque in recording the watts, the higher the loss in power. Much like an engines BHP is stronger at the flywheel than the wheel.

It doesn't really matter as long as you train to the numbers you're given. You might record 200 watts on your device, but 210 watts on someone else's.

Unless the turbo makers software makes allowance for this aspect? As long as any difference is measured and allowed for everything is sweet