E-Bike "motor" rating?

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eikido   100 mW

100 mW
Posts: 38
Joined: May 08 2019 5:07am

E-Bike "motor" rating?

Post by eikido » Aug 14 2019 12:19pm

In most EU countries, the maximum motor rating is 250w for e-bikes and electrical scooters.
Now is it that this motor rating is actually the combination of the controller and motor?
If i use an electrical motor that can handle 2000w but i use a controller that does not output more current/voltage needed to exceed system power to 250w, what is the rating? 250w or 2000w?
Is swapping out a controller only to limit the rating to 250w enough or does the motor also have to be maximum 250w?

qwerkus   1 kW

1 kW
Posts: 339
Joined: Jul 22 2017 4:00am

Re: E-Bike "motor" rating?

Post by qwerkus » Aug 14 2019 3:45pm

Its 250w maximum continuous power delivered by the motor. IIRC That means you can peak to 350w during startups. Given efficiency losses, this more like 300w continuous power draw at the battery level, and 400w peak. Though I ve never heard of police force using wattmeter. What really matters to law enforcement is speed, since it is easier to measure with existing equipment, but even then I never heard of someone being fined for pushing 35km/h. The thing is that those legal limits are kindof self enforcing: suppose you have an accident with an illegal bike; it basically means no insurance will cover the costs and you can easily run into 100 000€ of damage / hospital bills... it is up to you to evaluate the risk/benefit ratio...
That beeing said I bet there is a commercial scandal in the making here: it seems to me that many motors are grossly underrated, when I see a grandma riding a "legal" bosh unit zipping by on 10% grade where my bbs02 would easily burn the 700W.

john61ct   100 kW

100 kW
Posts: 1023
Joined: Dec 18 2018 2:06pm

Re: E-Bike "motor" rating?

Post by john61ct » Aug 14 2019 9:08pm

Design for stealth and keep speeds reasonable in built-up areas, and the odds are enforcement will remain with a light touch.


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