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I was just thinking Teslas don’t have transmissions. If the point of adding a motor to a bicycle is to augment the rider‘s power why is there a need for gears at all? Couldn’t the motor provide all the assistance needed for climbing hills or going fast on flats?
 

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I was just thinking Teslas don't have transmissions. If the point of adding a motor to a bicycle is to augment the rider's power why is there a need for gears at all? Couldn't the motor provide all the assistance needed for climbing hills or going fast on flats?
I use the first 4 gears regularly as I keep the bike in eco mode for minimal assistance. In trail mode I could power up any elevation with only the first 2 gears. However for steep uphill climbs even in boost or turbo mode, gears will still be necessary even with pedal assist.

Now at some point gearing will likely become integrated with the motor eliminating the traditional drivetrains but gearing itself on an ebike will still be necessary.
 

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Yes you are right. I‘ve never ridden an ebike but there are larger and heavier EV’s that do without a transmission. So you think it’s not currently possible to scale down a strong enough motor & battery to replace gears on a bicycle? However, we do examples of smaller electric vehicles that don’t have a gear boxes like scooters and skateboard boards.:unsure:
 

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Yes you are right. I've never ridden an ebike but there are larger and heavier EV's that do without a transmission. So you think it's not currently possible to scale down a strong enough motor & battery to replace gears on a bicycle? However, we do examples of smaller electric vehicles that don't have a gear boxes like scooters and skateboard boards.:unsure:
A motor that powerful would probably change the ebike's classification and be illegal on many trails that currently allow ebikes. With that much power an ebike would actually do the kind of damage to trails that many early on feared. Such as peeling out in the dirt etc. You would also need some sort of mechanism like gearing for the rider who needs to be able to pedal at a comfortable cadence.

Tesla's for example have very powerful motors in them and don't have a transmission, Chevy volts on the other hand have weaker motors and have a CVT transmission in them.
 

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On my first ebike demo, thats what i did. Using only the three modes to go up anything. Then I realized the cadence is not right, or I would spin out. The gear fine tuned the assistance.

Also, some ride in eco mode to mimic a normal bike for the workout, then increase the assistance when they are tired.
 

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Also a side thought what means does an electric motor have manage torque and speed the way a mechanical motor does through a gear box?
What do you mean by a mechanical motor? Not really sure what you're asking.

To answer the original question, a Telsa doesn't need a gearbox because electric motors have a very wide torque curve. Ebikes have gearbox/drivetrains because they are only assisting torque from human power, and humans are only efficient between a narrow RPM band, say 70-110 RPM.
 

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Also a side thought what means does an electric motor have manage torque and speed the way a mechanical motor does through a gear box?
A Tesla's motor(s) delivers 100% torque 100% of the time which is why they accelerate so ridiculously fast. The control system is controlling the RPM and how quickly that increases, think of it like a power drill, it always turns with the same force (torque) you just control the speed with the trigger.
 

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A Tesla's motor(s) delivers 100% torque 100% of the time which is why they accelerate so ridiculously fast. The control system is controlling the RPM and how quickly that increases, think of it like a power drill, it always turns with the same force (torque) you just control the speed with the trigger.
Yeah that's not true at all. If you push 5% throttle on a Tesla to go 25mph, it doesn't take off like a rocket ship than stop accelerating at 25mph. Similarly, if you try to remove a bolt with a drill or impact driver by pushing the trigger 5%, it will not untorque the bolt. Tesla's have the ability to accelerate so ridiculously fast because electric motors have the ability to produce near full torque from zero RPM, but they'll only do so when the motor controller commands full current.

Torque and speed are tied together and are controlled through a motor controller, torque is generally relative to current and speed is generally relative to voltage. The controller will handle both to give the amount of current and voltage needed to satisfy the command. As torque increases, speed increases (until forces at equilibrium) because F=ma.
 

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Yes you are right. I've never ridden an ebike but there are larger and heavier EV's that do without a transmission. So you think it's not currently possible to scale down a strong enough motor & battery to replace gears on a bicycle? However, we do examples of smaller electric vehicles that don't have a gear boxes like scooters and skateboard boards.:unsure:
Not without drastically reducing the ebike range. I use all my gears so I'm always climbing at the most efficient cadence and my power input is consistent. Even two people on identical bikes going the same speed can have large range differences just based off of pedaling habits and always being in the "right" gear.

I hope we get to a point where battery technology can be significantly smaller and lighter with greater capacity so range is not an issue, and I don't have to ride all day in eco trying to save every last juice of power.
 

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Tesla's have the ability to accelerate so ridiculously fast because electric motors have the ability to produce near full torque from zero RPM, but they'll only do so when the motor controller commands full current.

Torque and speed are tied together and are controlled through a motor controller, torque is generally relative to current and speed is generally relative to voltage. The controller will handle both to give the amount of current and voltage needed to satisfy the command. As torque increases, speed increases (until forces at equilibrium) because F=ma.
without nerding out on types of electric motors and torque/speed curves, this is the basic difference in operating characteristics between electric and internal combustion (assuming that is what is intended by "mechanical") motors.
 

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I rode an e-gravel bike and I had to use all of my gearing. I didn't put my bike into max power mode because I wanted to conserve the power for long distance. I ended up riding most of the time in 50 percent power boost mode and got around 70 miles out of my battery. I had to do some nasty climbs and using my whole gear range helped me out a ton.

Would be interesting if a manufacturer ever built an e-bike with a CVT style transmission. No need for gear shifting!
 

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I was just thinking Teslas don't have transmissions. If the point of adding a motor to a bicycle is to augment the rider's power why is there a need for gears at all? Couldn't the motor provide all the assistance needed for climbing hills or going fast on flats?
If a Tesla doesn't have a transmission, how does it move?

Sent from my SM-G930V using Tapatalk
 

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A motor that powerful would probably change the ebike's classification and be illegal on many trails that currently allow ebikes. With that much power an ebike would actually do the kind of damage to trails that many early on feared. Such as peeling out in the dirt etc. You would also need some sort of mechanism like gearing for the rider who needs to be able to pedal at a comfortable cadence.

Tesla's for example have very powerful motors in them and don't have a transmission, Chevy volts on the other hand have weaker motors and have a CVT transmission in them.
Volt uses a 4ET50,depending on year,not a CVT

Sent from my SM-G930V using Tapatalk
 
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