Calculating Rider Power Input on Ebikemotion X35 Bike and PP?

[lowb35]

After moving from flat south Louisiana to hilly upstate NY, I finally gave in and traded my standard gravel bike for a Class 1 ebike equipped with the Ebikemotion x35 system. It works brilliantly in that I can actually ride again rather than walk up hills. I'm getting better riding workouts now than I have since I moved here. However, since the PP measures total power it's obviously no longer accurate. I know my fitness has gone up since I know what my baseline FTP was when I first started riding the ebike, but there's only so long that I can pretend to have race fitness level when I'm an average 50-something woman who likes to ride a bike, LOL.

I originally used the PP meter to track and improve my fitness - at the time I got it, it was a great cost-effective solution since I'm not a competitive cyclist but I've still benefited greatly from power data.

I'm considering switching to a crank based power meter so that I can record *my* power, but I think that I may already have access to all the data I need to calculate it by subtracting what the bike expends from total power along the ride. The Ebikemotion system records wattage used by the system and the % of rider autonomy, and the PP records all power expended by both me and the bike. I'm all in on Garmin so I had been recording my rides on my Edge computer and uploading to both Garmin Connect and Strava. I also have a Garmin IQ app that collects some but not all the power data from the Ebikemotion system - basically just the assist level, not the wattage. In order to record complete bike power data I'd have to use the native Ebikemotion app which also uploads to Strava but won't connect to any other sensors besides my HRM. The ebike can replace my speed and cadence sensor but not a rider power meter.

Any ideas on how I can calculate my own power with what I have?

[Velocomp]

Well, you're on to something. In fact, we are working on an eBike torque sensor called VTorque, that works just as you describe!

The advantage VTorque has is that it can "read" eBike motor power directly, so the cyclist power is easy to figure-out.

It's difficult to understand all the different files you are using, but if you can somehow extract the motor power information, most definitely you can use the total power measured by PP to figure out how hard you are pedaling.

[lowb35]

Thanks for replying... I thought I might have been onto something. I'm currently working with two files - Garmin and ebikemotion - that can be uploaded to Strava (although for obvious reasons I only want to record 1 activity at a time in Strava, not 2). I have the PP Lite v.2 and wondered if the upgrade allowing me to record full rides in PP/Isaac would help in this? I don't even need to combine/compute the power data, just be able to compare total power with ebike power to get what I need.

[Velocomp]

Yes, to do what you want you will need the full ride file.

[lowb35]

That's a plan... Will the V3 unlock key work with my V2 PowerPod Lite?

[Velocomp]

That's a plan... Will the V3 unlock key work with my V2 PowerPod Lite?

Yes

[lowb35]

OK... I've updated my PowerPod and am making progress. Looked at the Ebikemotion GPX file in Excel and the motor power output is tagged as Power - records power expended in watts. Tried merging power/GPS data in Isaac and while the merge was successful, Isaac didn't read the Ebikemotion power data (maybe because it's not tagged as DFPM?). However, I downloaded Golden Cheetah last night and it accepted the Ebikemotion power data allowing me to compare the two data sets. I'll have to play some more with the data since Isaac did a better job of automatically aligning the time stamps between the two datasets without a lot of extra work on my part than Golden Cheetah, but it can be done. The difference between PowerPod and Ebikemotion appears to be consistent with what my measly power was when I rode a conventional gravel bike. But it also looks like I'm expending significant extra power of my own up hills, which was the main reason why I got a Class 1 ebike and confirms that my fitness is increasing.

The data in Isaac also indicate I'm using the brakes way too much going downhill especially on loose gravel, but that will just take practice and confidence in both me and my new bike. Though I also have to be careful of speeding pickup trucks, rogue ATVs and lots and lots of deer on my road.

Plan on going for a longer ride today to get better data. Not ready to share ride files yet (partially because I fear they'll expose what a bad cyclist I am LOL) but once I get some more data recorded and practice comparing the data sets will share.

[lowb35]

Figured it out! When I convert the ebike data to TCX using Golden Cheetah, Isaac reads the ebike's power data as DFPM. Now I can compare the two. Yesterday's ride was a commute rather than a workout, so I didn't expend as much as I would on a regular ride, other than up the hill to my house. But now I can see total power and the bike power, and from there extrapolate how much is my power.

[Velocomp]

Figured it out! When I convert the ebike data to TCX using Golden Cheetah, Isaac reads the ebike's power data as DFPM. Now I can compare the two. Yesterday's ride was a commute rather than a workout, so I didn't expend as much as I would on a regular ride, other than up the hill to my house. But now I can see total power and the bike power, and from there extrapolate how much is my power.

This sounds great; share a ride file when you're ready!