# How to determine actual work done by rider on a ride?



## Francis Cebedo (Aug 1, 1996)

I heard this can be done on some ebikes. How much total work I did on a given ride. Calories burned or Levos maybe? Shimano?

What's the measure? Kilojoules? Calories?

Formula is something like:

Total work on a ride - work by the motor = work by the rider.

How is it done? Just curious. I'm interested in comparing my 1 hour unassisted bike ride to my 2 hour ebike ride.


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## Klurejr (Oct 13, 2006)

fc said:


> I'm interested in comparing my 1 hour unassisted bike ride to my 2 hour ebike ride.


How many oz of beer was needed for recovery after the 1 hour unassisted vs the 2 hour assisted ride?

;-)

Joking aside I think a heart rate monitor would be a good place to start since you can track your heart rate for both rides and compare the data from that.


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## Francis Cebedo (Aug 1, 1996)

Klurejr said:


> How many oz of beer was needed for recovery after the 1 hour unassisted vs the 2 hour assisted ride?
> 
> ;-)
> 
> Joking aside I think a heart rate monitor would be a good place to start since you can track your heart rate for both rides and compare the data from that.


Yeah. Was that a double IPA hazy worthy ride or Lager spin?

Heart rate will provide some data.


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## J.B. Weld (Aug 13, 2012)

Power meter crankarm?


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## Klurejr (Oct 13, 2006)

fc said:


> Yeah. Was that a double IPA hazy worthy ride or Lager spin?
> 
> Heart rate will provide some data.


I think if you have a paid strava account you can import heart rate data into your rides and it adds that to the algorithm to determine calories burned. I have never seen how the setup is for an eBike ride in Strava, but I know my regular unassisted rides take into account my distance, elevation gained and my weight. But I take the number given to me with a grain of salt.


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## rockcrusher (Aug 28, 2003)

I think a heart rate based metric would be the best measure of calories burned however most of those are linked to the sport you are doing, and the speed you move. I regularly burn as many calories when I ride to work vs when I ride home but my ride in is mostly downhill while the ride home is uphill. I once had bookmarked a website that allowed you to determine actual calories from exercise based on wind speed, hill gradient. etc. I compared going up the hills I ride vs. going down but it wasn't super accurate either as the hills vary in grade and there are stop lights, etc.

The only way a person might actually know is by doing a VO2Max on a standard bike and then the same on an ebike and look at the difference in metabolism. It would give a baseline for effort of a duration.


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## rockcrusher (Aug 28, 2003)

craigsj said:


> It's unlikely you can know this unless your bike makes information available for this purpose and explains how it can be used.
> 
> If you know, though, what your proportional assist level is and assume that it is consistent through the ride, then you can estimate rider energy from battery energy. That doesn't account for any time you are pedaling over the speed cutoff though.
> 
> You really an additional measurement device, like power pedals or a powertap wheel, to be sure. There's a device that estimates power using a handlebar mount. Sounds crazy of course.


 The only problem with a driven powermeter like a hub or crank arm is that it will recording the electric propulsion that is added to the drive train. Unless your power delivery is not through the drivetrain but front hub then this would skew this metric too I suspect.


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## Lojack (Feb 16, 2018)

Yeah, measure average power output (see a discussion at https://en.wikipedia.org/wiki/Cycling_power_meter for different methods). Then Work = ave. power x time pedaling. This does not represent total energy expenditure done by the rider though--the human body is roughly 25% efficient at converting food Calories (energy) into useful work. So if you did say 100 kJ of work turning the cranks you probably burned roughly 4 times as much energy (400 KJ)--most of that difference comes out as heat. Note: 4.186 KJ = 1 "food" Calorie.


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## J.B. Weld (Aug 13, 2012)

rockcrusher said:


> The only problem with a driven powermeter like a hub or crank arm is that it will recording the electric propulsion that is added to the drive train. Unless your power delivery is not through the drivetrain but front hub then this would skew this metric too I suspect.


I agree that a power meter hub wouldn't work but I think a crankarm one would since they just measure stress on the crankarm. Or pedals. Seems like either of those would provide the most accurate measurement of work done and calories burned.


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## Francis Cebedo (Aug 1, 1996)

craigsj said:


> It's unlikely you can know this unless your bike makes information available for this purpose and explains how it can be used.
> 
> If you know, though, what your proportional assist level is and assume that it is consistent through the ride, then you can estimate rider energy from battery energy. That doesn't account for any time you are pedaling over the speed cutoff though.
> 
> You really an additional measurement device, like power pedals or a powertap wheel, to be sure. There's a device that estimates power using a handlebar mount. Sounds crazy of course.


So the motor knows how much power it's putting out. The motor also knows how much power the rider is contributing (since it has a torque sensor and has all the rpm data).

Specialized at some point told me they can deliver this data to the end-user. But I have not explored it til now.


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## BIke N Gear (Sep 27, 2004)

Blevo app reports the info you are asking about for Levo.


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## chazpat (Sep 23, 2006)

Seems I recall Moe Ped was able to calculate this but I don't know how he did it. Maybe he'll drop in here.


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## scatterbrained (Mar 11, 2008)

fc said:


> I heard this can be done on some ebikes. How much total work I did on a given ride. Calories burned or Levos maybe? Shimano?
> 
> What's the measure? Kilojoules? Calories?
> 
> ...


If you're riding a Levo it should report rider power output, but you'll need to use the Mission Control app, which won't let you use your HR monitor. Just remember that the mission control app has a bad habit of pausing and then not restarting. I've stopped using the Mission Control app and just went back to my Garmin. Now I have speed, cadence and HR but no power. Oh well. I've determined that my average power output on the e-bike is just over half what it is on my regular bike.


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## ninjichor (Jul 12, 2018)

Looked up what the battery offers: 500 Wh is 1800 kilo joule. That's how much energy strava+elevate app says I output on a 40 mile ride on a normal mtb.

Makes me wonder what the testing standard is, to determine how much range the ebike gets in each mode, despite assisting the rider.


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## Francis Cebedo (Aug 1, 1996)

BIke N Gear said:


> Blevo app reports the info you are asking about for Levo.
> 
> View attachment 1257373


HOLY MOLY!!! That is amazing.


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## Francis Cebedo (Aug 1, 1996)

scatterbrained said:


> If you're riding a Levo it should report rider power output, but you'll need to use the Mission Control app, which won't let you use your HR monitor. Just remember that the mission control app has a bad habit of pausing and then not restarting. I've stopped using the Mission Control app and just went back to my Garmin. Now I have speed, cadence and HR but no power. Oh well. I've determined that my average power output on the e-bike is just over half what it is on my regular bike.


So the Mission Control App says it too outright huh? That is pretty darn good.

None of my unassisted bikes have this unless I install a power meter. I suppose Strava will have an approximation.

fc


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## Crankout (Jun 16, 2010)

Like mentioned, seems the HRM would capture effort on both assisted and unassisted rides provided that the rider's general well-being is similar in both efforts. HRM's have their shortcomings, but it seems a power meter may not work correctly on an ebike?


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## hikerdave (Mar 8, 2006)

fc said:


> I heard this can be done on some ebikes. How much total work I did on a given ride. Calories burned or Levos maybe? Shimano?
> 
> What's the measure? Kilojoules? Calories?
> 
> ...


My Yamaha PW-SE outputs rider power; the new Garmin Edge 530 and Garmin Edge 830 as well as the Strava app will read this power. I have personally tested all three. Disclosure and dislaimer; I work at Garmin but am speaking for myself.


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## 127.0.0.1 (Nov 19, 2013)

J.B. Weld said:


> Power meter crankarm?


that's a bingo, 
and it will be accurate vs whatever that app thinks it's telling you


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## Francis Cebedo (Aug 1, 1996)

Power meter crank arms are not necessary. Most good ebikes already have a torque sensor and a power meter. And it seems like the good ebikes display rider output, instantaneous and for the whole ride. Should be fine for the application, which is not TDF training.


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## KenPsz (Jan 21, 2007)

One way you could do it is to put a meter between the motor and batteries. That way you can measure the watts that are being pulled when the rider is pedaling vs. not. Problem is most of the factory bikes would let you do this.


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