Ebike Motors: A Political and Historical View

[recumpence]

1,000 watts in not even legal.

Man, get it through your head, a racing class is NOT going to happen! I am so sick of every post you make promoting this idea you have in your head for a racing class.

You need to try posting something people actually want to read and is helpful to others instead of this tired garbage you continually spew about "EBRR". I, for one, am TIRED of hearing about it!

Get it through your head, Man!

Good grief!

Matt

 

[safe]

Legal ebikes are allowed to produce 750 watts as their "rated" load. Obviously, due to the shape of the permanent motor powerband it's possible to get slightly more at peak power, so the bikes that are already sold legally now in the US operate with about 1000 watts of input.

So in effect 1000 watts is legal on the input side and 750 watts is "rated" as legal on the output side, but people are already sneaking a little above that.

Basically when you subtract performance inefficiency you get a 1000 watt input limit and a 750 watt output limit based on the law. (within a margin of error of 5%-10%) If there were any complaints by law enforcement that 1000 watts was too much and they wanted 950 watts or 900 watts on the input then I'd comply with their request and expect any competition to do as well.

--------------------------------

Ebikes are either legal (close to it) or they are not.

I was thinking about a sort of humorous idea...

What if someone invented what they called the "NASA ebike". The idea would be to place decals about NASA programs all over it and sell the product to little kids that would imagine themselves as astronauts.

Is that illegal?

No, not if the motor is legal and it has pedals and it's sold with some kind of speed limiter so that the motor can't go over 20 mph. (or higher depending on the state laws)

The point is that it's a legal thing to sell an "Electric Bicycle Road Racer" as a sort of toy product. People might then take the "toy" and modify it enough to be able to have races with them or they can just keep them as a fun toy.

What we can say for a fact is that 18 hp is no longer an ebike... that's no "toy"... that's a full blown electric motorcycle. Plain and simple you cross the line of ebike laws when you get that far outside the rules. A little cheating is tolerated... maybe if you stay small enough you can stay below the radar... but the moment the law is somehow involved you lose everything you have. You can't win in the long run if you expand.

Now maybe all you want is to make a little money on the side and not make a fortune doing this.... small business is a good thing... but based on the way things are setup you're never going to be selling your product to a large consumer base.

You are like Al Capone... as long as the thing you sell is illegal you will have an audience of people that are attracted to that gangster outlaw image... but the mainstream cannot tolerate 18 hp ebikes. (and will not tolerate)

----------------------------------

But hey Recumpence... it's not that I'm singling you out as the only offender here. I've been consistantly stressing the importance of sticking to the law so that we have some common ground with ebikes which we all share. As people like yourself cross the legal lines and start to make ebikes a somewhat underground and illegal activity it just changes the role in society in general.

If the laws changed... if ebikes could be powered any way they wanted... then I'd be with you in your efforts and be chasing after "Big Power" too. But I just don't ever see the laws changing to be less strict. Typically laws get stricter rather than looser.

 

[recumpence]

Since you insist on ignoring my comments, I will repeat it AGAIN.

Man, get it through your head, a racing class is NOT going to happen! I am so sick of every post you make promoting this idea you have in your head for a racing class.

You need to try posting something people actually want to read and is helpful to others instead of this tired garbage you continually spew about "EBRR". I, for one, am TIRED of hearing about it!

 

[safe]

What... do you have a crystal ball or something?

I totally disagree. In fact it's probably more of an "inevitable truth" that as ebikes emerge from the shadows that they will be raced.

As I see things we are at about the place in ebike history that corresponds to when the "Yamaha Moto-Bike" was released for BMX. No one is sure yet what the future is going to look like and yet it's inevitable that things will be different tomorrow than today.

Just about everything gets raced eventually...

EBRR "Electric Bicycle Road Racing" is simply my way of taking ownership of what will be the inevitable future that one day racing will happen. The actual name for the racing and the bikes themselves very well might not look anything like I envision, but it's just like with the "Yamaha Moto-Bike" they didn't know where things would go either.

I figure that things in the ebike world don't really get interesting for at least five years from now... so I'm ready to wait.

----------------------------

I'm very interested in these Induction motors and the potential for things like the Switched Reluctance motors. Did you realize that with those motors the motor rpm is based on the frequency and that's it, there are no magnets that demand high rpm to operate efficiently. Plus, if you increase the number of phases that reduces the motor speed. What suddenly becomes possible is a motor that actually can pull well (efficiently) at 500 rpm or less. This makes all the stuff you are doing with these multistage geardowns obsolete because the motors can be used in a direct drive to the chain.

History has a way of having twists and turns to it... so I'm not worried that things are fully defined yet. However, the Federal Ebike Law and all the state laws that are similiar to it will likely not change much without some kind of major political effort. The Federal Ebike Law was just recently passed and so changing it again is unlikely in the near term. In order for the future to have legal ebikes with large levels of horsepower things would have to be radically altered. I just don't see any future (in the larger consumer economy) for ebikes that are using "Big Power".

 

[johnrobholmes]

Your product undermines my efforts to try to get a 1000 watt racing class started.

People are going to race what they please. There isn't just one ICE racing class, now is there? The only thing that Matt does to you is get under your feathers.

I'm very interested in these Induction motors. This makes all the stuff you are doing with these multistage geardowns obsolete because the motors can be used in a direct drive to the chain.

How so? Torque is still related to geardown, and the induction motor still has an RPM limit before mechanical limits(or load limits) take over. You will still need geardown designed for the motor size. The power curve will merely be different when comparing to a PM motor.

 

[johnrobholmes]

I just don't see any future (in the larger consumer economy) for ebikes that are using "Big Power".

Yeah really. It's not like you can buy scooters with engines bigger than 50cc. Who would want choices anyway? Everybody here only wants 1000w bikes last I heard, and they want them identical and installed on the same bike. All painted purple.


Viva la conformity!

 

[safe]

The struggle that the ebike world has been faced with since the beginning is being able to distinguish itself from other categories like emotorcycles. That's the whole point of reviewing the history in this thread. In the beginning the idea (in Europe) was that the electric power would only moderately assist the rider and any more than 250 watts would be "unthinkable", "illegal" and "unsafe". Later on in America there was a sort of revolution of thinking within government where they decided to unify the states with a 750 watt law. Now we have the "ebike anarchists" that exist in the shadows and have went not just a little past the laws, but have stretched things to the point of them being unrecognizable. It's this anarchist phase that I'm very sceptical of in the long run. While I can see some profits to be made while peddling illegal vehicles the eventual destiny is that the law catches up with people doing it and it gets shut down. In reality the anarchists never come out of the shadows... the mainstream like conformity, safety and security.

The "normal" people want to be "safe".

 

[safe]

How so? Torque is still related to geardown, and the induction motor still has an RPM limit before mechanical limits(or load limits) take over. You will still need geardown designed for the motor size. The power curve will merely be different when comparing to a PM motor.

Not true. Induction motors produce power based on the frequency of the power and the design of the windings. As you increase the number of poles in the windings it decreases the motor rpm to produce the same torque. Induction motors are based on "slip" so slow speed torquing is not the same problem that it is for the permanent magnet motor. I'm thinking that it's probably the answer to eliminating the geardowns.

Motor Speed = (120 * Frequency) / (Total Effiective Poles/Total Phases)

Example One: A Three Phase motor uses 12 poles in total, but they wind it so that it functions llike a 6 pole motor (more typical) by doubling up the windings so you end up with an effective "2 pole" motor:

(120 * 10Hz) / (2) = 600 rpm
(120 * 50Hz) / (2) = 3000 rpm

Example Two: A Three Phase motor uses 12 poles in total and they use all of them individually, so you get an effective "4 pole" motor:

(120 * 10Hz) / (4) = 300 rpm
(120 * 50Hz) / (4) = 1500 rpm

...the first motor is more typical and resembles the typical permanent magnet motor, but the "4 pole" runs with the same torque, but runs more slowly. The Tesla uses a "4 pole" AC Induction motor to the best of my knowledge for this reason... it produces more low end torque this way.

This might revolutionize the ebike world... if it's correct... or it turns out a failure... we will see...

 

[johnrobholmes]

I understand how an AC motor works, safe. Induction motors are used because they are really cheap, not because they have a torque or power advantage.

You will STILL need geardown to suit the motor. Get a large enough diameter and you may not need much geardown, but it comes at a penalty to motor weight instead of drivetrain weight. Don't unlearn everything you have found with brushed motors, it all still applies.


How is low speed torque a problem for PM motors? You do realize that PM are made with high pole counts as well, right?

 

[safe]

I understand how an AC motor works, safe. Induction motors are used because they are really cheap, not because they have a torque or power advantage.

The Tesla Roadster uses a Three Phase Ac Induction motor with 4 poles.

I think the problem with most of the lower powered AC motors is that they tend to be cheap and of lower efficiency design. From what I've read of the theory of AC Induction motors it does appear that a 1KW motor is possible to be done so that you can eliminate the geardown units entirely.

If it can be done then ebike history changes...

One asks the question:

"Do I care about the power-to-weight ratio or am I interested in a wider and more usable powerband?"

...if you stay within the 750 watt legal limit and want to span speeds from 0 to 60 mph WITHOUT needing multispeed gearing the only way to do it is with an AC Induction motor. You can easily start at 10 Hz and go up to 100 Hz... so gearing is not a problem.

Illegal power levels don't interest me... I just want to invent a "product" so that I might do what is mentioned in the next posting.