After some quick test rides and some code adjustments, I rode Tronbike to work today sans lower fairings - hence the "Nekkid" part. I sort of like the look, and am wondering if an elaborate array of cable covers and directed air tubing could be formed to make an exposed battery pack look "cool".
The save-on-shutdown circuit is proving finicky, and my reset code would only reset the odometer, but not the watt hrs gauge. I am liking the "watts per mile" meter, the only reasonable number collected so far being 127 Wh/mile.
I also reset the pack size from 3300 Watt-Hours to 1100 Watt-Hours so the % remaining will be more useful. The Killawatt is showing about 600W-Hr used in todays commute, very close to the numbers the TBM recorded (when added together for both directions due to shutdown switch annoyances).
Monday, June 21, 2010
Saturday, June 12, 2010
Bike Doping Analysis
I am finally catching up on the accusation/rumors/suggestions that Fabian Cancellara was using electrically assisted race bikes for his recent victories in the Paris-Roublaix and Ronde van Vlaaderen. An avid cyclist, my regular group made comment, I assumed immediately the batteries are such that it would be a waste of energy to haul them around.
Some articles:
http://www.velonation.com/News/ID/4415/Fabian-Cancellaras-so-called-motorized-doping-debunked.aspx
http://www.velonation.com/News/ID/4412/Saxo-Bank-denies-its-riders-used-motorised-bikes.aspx
You Tube Video explaining the controversy, and how it works:
http://www.youtube.com/watch?v=8Nd13ARuvVE
A product, Gruber Assist available since 2008 (I want one, just because I AM TRONBIKES!) - what awesome advertising, sort of evil I guess.
Specs:
100 watts for 90 minutes, 900g + battery pack, Gruber has a table of battery capacity
Pro riders churn out 500-600 watts in regular hard efforts, likely more peak. Cancellara is a horse, lets assume 800 for the accelerations, a 10% boost would
indeed help - as the late Edmund R. Burke of "Cycling Science" once published, time-trial athletes with 10% better times put out 11% more power. So in theory,
any additional power to a rider is significant - a 100 watt boost = 100 watts faster!
The big question to me is, would the weight of the system be worth hauling along for distance before putting it to use - would the system help?
The Gruber people have a big chart (though a bit confusing, maybe backwards?) for a hybrid bike pulling different amperages, with the resulting range - for some reason, maybe its backwards(? sending email) the bike runs farther when running faster in this chart - I'll send email on this.
Paris-Roubaix =262 km/hr averaging 32.9 km/hr (http://www.steephill.tv/classics/paris-roubaix/), but its really flat, like 490 ft peak (http://www.runsaturday.com/Maps/3462).
Assuming the system is invisible, we can only assume additional work to haul
this around is due to gravity. With a peak of 490 ft, lets triple this in my test model to 1500 feet, about 500meters.
Gravity pulls (acceleration) at 9.81 m/s^2, Force = Mass * Acceleration, and work is force through a distance expressed as joules
Work = (9.81 m/s^2 * Mass) * 500m
Mass = weight of system, and beyond the motor itself, the weight is batteries, with power storage usually noted in Amp-Hours, lets use the 900g number
Work = 9.81 m/s^2 * 1kg * 500m = 4905 m2 kg/s2 = 4905 Joules = 4905 Watts - sec of work. A watt-sec is not power, but a unit of capacity/work that requires
energy.
With 100% efficiency, 5000 W-sec = 5000 W-sec/3600s = 1.4 W-hr expended to haul this extra 1 Kg system around by gravity alone. A single 18650 Li-Ion battery
can store up to 3000 mAh at 3.7 volts - enough to cover most of the weight of the system - each 18650 itself only weighs about 50g
1 Watt - Hour = Volts * Amps * Time = 3.7 Volts * 3 A-hr = 11.1 Watt - Hour
Gruber calls out capacities up to 10 Ah, which would weigh 10 Ah=3000Mah * X batts, X=10Ah/3Ah = 3.33 batteries, * 0.50g = 170g...very light
Working off the chart, 12 Amps
10Amps-Hr/12Amps = 0.83 Hr = 50 minutes, as on the Gruber chart. Paris-Roubaix was about 6.5 hours long.
100 watts for 50 minutes = 100 watt (50/60) hours = 83 Watt-Hours, only 8 batteries, not much weight penalty
So far I'm not convinced Cancellara was bike doping(or would need too), but I am convinced bike doping could be a real advantage in a flat race like Paris-Roubaix if any of my calculations above are right using the "perfectly efficient" energy conversions I am assuming. I'll sleep on the generic model parts above and maybe generate a spreadsheet to model possible scenarios more closely.
Some articles:
http://www.velonation.com/News/ID/4415/Fabian-Cancellaras-so-called-motorized-doping-debunked.aspx
http://www.velonation.com/News/ID/4412/Saxo-Bank-denies-its-riders-used-motorised-bikes.aspx
You Tube Video explaining the controversy, and how it works:
http://www.youtube.com/watch?v=8Nd13ARuvVE
A product, Gruber Assist available since 2008 (I want one, just because I AM TRONBIKES!) - what awesome advertising, sort of evil I guess.
Specs:
100 watts for 90 minutes, 900g + battery pack, Gruber has a table of battery capacity
Pro riders churn out 500-600 watts in regular hard efforts, likely more peak. Cancellara is a horse, lets assume 800 for the accelerations, a 10% boost would
indeed help - as the late Edmund R. Burke of "Cycling Science" once published, time-trial athletes with 10% better times put out 11% more power. So in theory,
any additional power to a rider is significant - a 100 watt boost = 100 watts faster!
The big question to me is, would the weight of the system be worth hauling along for distance before putting it to use - would the system help?
The Gruber people have a big chart (though a bit confusing, maybe backwards?) for a hybrid bike pulling different amperages, with the resulting range - for some reason, maybe its backwards(? sending email) the bike runs farther when running faster in this chart - I'll send email on this.
Paris-Roubaix =262 km/hr averaging 32.9 km/hr (http://www.steephill.tv/classics/paris-roubaix/), but its really flat, like 490 ft peak (http://www.runsaturday.com/Maps/3462).
Assuming the system is invisible, we can only assume additional work to haul
this around is due to gravity. With a peak of 490 ft, lets triple this in my test model to 1500 feet, about 500meters.
Gravity pulls (acceleration) at 9.81 m/s^2, Force = Mass * Acceleration, and work is force through a distance expressed as joules
Work = (9.81 m/s^2 * Mass) * 500m
Mass = weight of system, and beyond the motor itself, the weight is batteries, with power storage usually noted in Amp-Hours, lets use the 900g number
Work = 9.81 m/s^2 * 1kg * 500m = 4905 m2 kg/s2 = 4905 Joules = 4905 Watts - sec of work. A watt-sec is not power, but a unit of capacity/work that requires
energy.
With 100% efficiency, 5000 W-sec = 5000 W-sec/3600s = 1.4 W-hr expended to haul this extra 1 Kg system around by gravity alone. A single 18650 Li-Ion battery
can store up to 3000 mAh at 3.7 volts - enough to cover most of the weight of the system - each 18650 itself only weighs about 50g
1 Watt - Hour = Volts * Amps * Time = 3.7 Volts * 3 A-hr = 11.1 Watt - Hour
Gruber calls out capacities up to 10 Ah, which would weigh 10 Ah=3000Mah * X batts, X=10Ah/3Ah = 3.33 batteries, * 0.50g = 170g...very light
Working off the chart, 12 Amps
10Amps-Hr/12Amps = 0.83 Hr = 50 minutes, as on the Gruber chart. Paris-Roubaix was about 6.5 hours long.
100 watts for 50 minutes = 100 watt (50/60) hours = 83 Watt-Hours, only 8 batteries, not much weight penalty
So far I'm not convinced Cancellara was bike doping(or would need too), but I am convinced bike doping could be a real advantage in a flat race like Paris-Roubaix if any of my calculations above are right using the "perfectly efficient" energy conversions I am assuming. I'll sleep on the generic model parts above and maybe generate a spreadsheet to model possible scenarios more closely.
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