I've read a few threads, usually related to range, and people bring up efficiency of the motor(s). Some folks say a motor's peak efficiency is at full speed, and some say a percentage of that, for instance. Sometimes the discussion is related to efficiency of a particular motor through it's operating band, and other times it's discussed while comparing motors. I've always equated efficiency more like power converted to motion vs heat; but not correlating to range, which I believe is really only a function of the rider's throttle hand and/or willingness to pedal.
Playing with the Grin simulator, it does appear as though the efficiency curve is always ascending up to top speed. This can be seen in System A, which I modeled for my bike. System B is the system in each case, except adjusting the amount of throttle being applied by the rider.
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Notice efficiency went up, not down, because the efficiency curve isn't static, but shifts based on the motor input voltage (speed).
Throttling down even more and efficiency peaks (at around 30.3mph) then starts decreasing.
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Finally, throttling down further, the efficiency drops back down to being almost equal to the efficiency at full throttle.
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The third simulation really shows the disconnect between efficiency and effect on range. The efficiency in both cases is nearly identical, yet system A travels 21 miles on a charge, while system B travels 137 miles. Basically, if you want range, it doesn't matter much how efficient the motor is, relative to the impact of your throttle hand has. This also seems to be somewhat consistent with my motor temperature testing, since I've found throttling down to a certain speed range (more efficient?) allows for longer steep climbs without overheating, and slower or faster than that speed makes the temps rise more quickly.
I'm going to play around with one of the Grin motors next, since those have the temps modeled.
Playing with the Grin simulator, it does appear as though the efficiency curve is always ascending up to top speed. This can be seen in System A, which I modeled for my bike. System B is the system in each case, except adjusting the amount of throttle being applied by the rider.
Motor Simulator - Tools
Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...
![ebikes.ca](/sphere/proxy.php?image=https%3A%2F%2Febikes.ca%2Fpub%2Fstatic%2Fversion1722576229%2Ffrontend%2FSmartwave%2Fporto_child%2Fen_CA%2FOnilab_Theme%2Ffavicon-32x32.png&hash=bcdac659d6c392724bfa4dfa015e90eb&return_error=1)
Throttling down even more and efficiency peaks (at around 30.3mph) then starts decreasing.
Motor Simulator - Tools
Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...
![ebikes.ca](/sphere/proxy.php?image=https%3A%2F%2Febikes.ca%2Fpub%2Fstatic%2Fversion1722576229%2Ffrontend%2FSmartwave%2Fporto_child%2Fen_CA%2FOnilab_Theme%2Ffavicon-32x32.png&hash=bcdac659d6c392724bfa4dfa015e90eb&return_error=1)
Finally, throttling down further, the efficiency drops back down to being almost equal to the efficiency at full throttle.
Motor Simulator - Tools
Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...
![ebikes.ca](/sphere/proxy.php?image=https%3A%2F%2Febikes.ca%2Fpub%2Fstatic%2Fversion1722576229%2Ffrontend%2FSmartwave%2Fporto_child%2Fen_CA%2FOnilab_Theme%2Ffavicon-32x32.png&hash=bcdac659d6c392724bfa4dfa015e90eb&return_error=1)
The third simulation really shows the disconnect between efficiency and effect on range. The efficiency in both cases is nearly identical, yet system A travels 21 miles on a charge, while system B travels 137 miles. Basically, if you want range, it doesn't matter much how efficient the motor is, relative to the impact of your throttle hand has. This also seems to be somewhat consistent with my motor temperature testing, since I've found throttling down to a certain speed range (more efficient?) allows for longer steep climbs without overheating, and slower or faster than that speed makes the temps rise more quickly.
I'm going to play around with one of the Grin motors next, since those have the temps modeled.