Speed Sensor 2 and Auto wheel size using Peloton

acousticbiker said:

Or does it require GPS distance?

It does.

acousticbiker said:

Would it work with power and HR data?

Determining wheel size based on HR or power? No, it won't work.

Thanks, what I meant was whether there may be algorithm to estimate distance based on power output and HR given Garmin knows my VO2max and other stats but, yeah, a bit of a stretch

Well, I tried the Auto setting today since I couldn’t find a wheel size  to try for Peloton. Distance was about double what Peloton software recorded and max speed was almost triple. 

I edited the distance and max speed in the activity in Connect - any chance those adjustments will be incorporated by the Speed Sensor to calibrate the Auto wheel size functionality?

I don't have a Peleton bike but judging from its pictures, there is no wheel to mount speed sensor on, for the first place.

The front flywheel is not the equivalent of the "outdoor" bike rear wheel (or front wheel for that matter).
Peleton's crank, belt, flywheel and resistance knob all form kind of "outdoor" bike's drivetrain. You can maintain the same cadence but increase resistance. Peleton will increase your speed then (or I believe so), without a change to the rotational speed of the crank/flywheel (where you might have tried to mount SS2).

There is a 'hub' on the Peloton flywheel onto which I mounted the SS2

But flywheel rotational speed alone has nothing to do with the road speed reported by Peloton.

Ah, ok, I hadn't considered that and see that Peloton hasn't published their algorithm for speed (or distance) so there's a lot of speculation out there. Here's one analytical perspective: https://ihaque.org/posts/2020/12/25/pelomon-part-ib-computing-speed/

If that speed sensor is anything like mine (Speed sensor original), you can go into the sensor settings of watch/headunit and do manual calibration of the speed.  So... if you are getting double distance on a typical ride... just cut the wheel diameter setting that is in there by half.  

This will not be true speed or distance on rides, but for steady state or mixed use... it will likely be close and give you something.  BUT - personally I would just track the time/HR on watch and input a distance into Garmin after that is reflective fo effort if you track total distance.  I do similar on my zwift rides on trainer.

And/or...  you should be able to setup Sharing to Strava of your peloton rides, then export out of Strava to import into Garmin. Then you will have power/HR/speed/etc.

Yeah, I tried doing manual calibration based on the direction/size of error and even after multiple rounds could never get it close enough so have ditched it and will manually enter the distance and max speed into the activity (DFC captures everything else, including power, and factors into Garmin's Training Readiness, Recovery, etc algorithms)