eBike Power - One Size Fits All?

Many ebike models, like the Specialized Levo or Creo, come in sizes from S to XL to accommodate various sizes of rider, but all with the same size battery and the same motor.

Ebike classes and watt limits take no account of the mass of the "vehicle."

From cars to boats to planes, when comparing them side by side, the larger one will nearly always have a larger motor.

In the case of ebikes, the total vehicle "size" is the weight of the bike plus the weight of the rider. Some ebikes plus rider weigh twice as much as others. If the motor is the same size in both, they will have roughly twice the acceleration for a 100 pound rider as for a 200 pound rider.

It's possible to find bikes with more or less power, but the concept I'm getting at is that anyone who buys, for example, a Specialized Creo, no matter how big or how small they are, will get the exact same size motor.

It's a bit of a late night thought, perhaps some of you have had it as well... ?


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The European Union decided any 2 wheel vehicle with more than 350 watts power is a motorcycle, and requires a license plate, insurance, and a driver's license.
Many of the US states have jumped down this hole. Most built bikes comply with this law to be able to be sold in 50 states.
I bought a 1200 W hub motor kit, and do not feel an intense risk of injuring a pedestrian with it. It does pull me up 15% grades at 6 mph instead of 3.


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There are short 250# riders using small frames and 150# riders on XL frames. Bike makers have no way of knowing what the "vehicle mass" will be based solely on frame size. Considering the power limitations of the three class system, manufacturers don't have much range in motor size to work with. Multiple motor sizes for the same model bike would only serve to drive up production costs.

There are alternatives to three class compliant bikes. If you feel you need more power, do what a lot here do and buy a custom bike or build your own with a high wattage motor.

Stefan Mikes

Well-Known Member
The European Union decided any 2 wheel vehicle with more than 350 watts power is a motorcycle, and requires a license plate, insurance, and a driver's license.
The European Union decided any two or three wheel vehicle above 250 watts of continuous rated power and the motor assistance above 25 km/h but with the motor up to 4 kW and the assistance limited to 45 km/h is the L1e-B, an electrical moped. While the license plate and insurance are mandatory, the driving license is not required except for older teenagers. Wearing a cycle helmet is mandatory; the UK requires a motorcycle-grade helmet is worn.

Funny to think, no large manufacturer (except some rare Yamaha driven e-bikes, I think) has used a 500 W motor on their S-Pedelecs even if up to 4 kW is allowed.
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Thanks for all of your thoughts on the matter.

This is just one of those academic issues I think about while stargazing at night.

Still interesting to me that smaller, lighter riders experience the same bike model so very differently from larger and heavier riders and it more often than not is left out of people's comments about the bike and it's ride.


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I think you have a valid point, especially as I'm one of the bigger guys you're likely going to see on a bike (6'2"/315lbs). As I'm an avid DIY'er, and enjoy enough power to get me and the bike moving quickly when I want it too, the gear driven motor providing the go power on my bike reflects that fact and suites my needs just fine.....

Add the fact that proving my bike has 2-3 times the power it was delivered to me with would be extremely difficult has not gone unnoticed. The motor carries no markings.... so proving anything about it would be WAY beyond the means of most that might be curious.....

Point being, find a bike that seems to suit your purposes, ride it for a while, then change whatever it is that you think might make it "better"!