First, I have done much searching on this subject. I read that escooters are illegal and ebikes are legal in the UK (broadly speaking, if 250W, pedal assist and speed limited). It seems to me that the main difference between an ebike and escooter is that the bike must have pedals and the ebike be pedal assist. Does than mean I could put pedals on a raised escooter (with a seat) and call it an ebike? Question applies mainly to UK, US and EU please, but local only knowledge will be welcome too. Target wheel sizes are 8" front and 6" rear.

In a related question, e-tricycles seem to be identical in law to ebikes. However, would very small twin back wheels get it classed as an escooter? (eg: both 5 inch). My aim is to make a very compact foldable ebike for dragging on trains and across very large concourses. Don't feel as if you have to answer both questions :-)

enter image description here Sample etrike for ref from here (ps: I prefer much smaller)

  • 3
    This site is more about bicycles and less about e-vehicles or law. A law-related forum in the target country would probably be a better place to ask.
    – ojs
    Commented Jul 10, 2021 at 13:39
  • Can someone please explain the down mark? It's not a legal question - it's about what determines a vehicle to be a bike (or ebike) or otherwise. I added "in law" to stop guesses and encourage well considered answers. Can you imagine this question being well received on a law forum? Ridiculous comment. Besides, this is about a product for the globe. Is the hostility because "we don't like ebikes around here"? Whatever. Ps: I already know about the legality and said as much. Commented Jul 11, 2021 at 15:36
  • 1
    How is it not a traffic law question? Where I live the law is more or less "anything goes as long as it's claimed to be limited to 250W and 25 km/h" without any criteria whether it's a bicycle, but the question seems to assume that there are some requirements.
    – ojs
    Commented Jul 11, 2021 at 16:18
  • It would be interesting to know why does it have to be a bicycle, too. You want a scooter, why can't you just get a scooter?
    – ojs
    Commented Jul 11, 2021 at 16:22
  • 1
    @ojs because the OP is in the UK where the law doesn't make provision for e-scooters. Privately owned ones are therefore illegal to use on public land, while there are trial rental schemes in some areas allow use on roads (as in with the cars not the pedestrians) and bike paths.
    – Chris H
    Commented Jul 13, 2021 at 14:38

3 Answers 3


This is probably more of a law-question, and less-related to bicycles.

My understanding is that:

  • A bicycle has functional pedals, and is powered by human effort on those pedals.

  • A scooter (kick-scooter) does not have pedals, and is powered by pushing your foot against on the ground.

Wheel size is irrelevant and has no bearing on whether something is a bike or a scooter. Also, there's nothing about needing a saddle (seat) to be classed as a bicycle.

In the UK there are limits set on the electric-assist part of an ebike, that will involve cutting-off the assist at a certain speed, and a maximum permitted wattage. The bike also must function as a bike, so when the battery is empty you can still ride it.

I'm unaware of the e-scooter rules there.

I suggest you look at something like the Sinclair A-Bike, which is definitely a bicycle, and is UK based. This would be about the bare-minimum to be a bicycle. https://en.wikipedia.org/wiki/A-bike

enter image description here
I suppose this could be called an eA-Bike

The number of wheels is possibly contentious. A BIcycle has two wheels by definition, but many countries have laws that state "pedal cycle" or similar wording. So a tricycle has exactly the same status as a bicycle because both are Pedal Cycles.

The relevant road laws often state a maximum width for a pedal cycle, which is more relevant for a trike or trailer.

Nominally, a Unicycle also falls under "pedal cycle" but I've never seen a unicycle with brakes, let alone two independent brakes as required in many western countries. Any less than one

  • 1
    I was unaware of the A-bike. I think that answered most of my question! (Will mark it as best soon). Thanks. Commented Jul 10, 2021 at 14:49
  • 1
    In the UK, some laws relating to bicycles refer strictly to two wheels, others to two or three, but some explicitly include unicycles. Pedals are always definitive, even with e-bikes. So the e-scooters you sometimes see with a saddle aren't bikes and wouldn't be even with bike wheels
    – Chris H
    Commented Jul 12, 2021 at 10:29
  • 1
    @Criggie e-scooters in the UK are only legal as part of approved trial rental schemes (and I believe only supposed to be rented to those who can drive a car), but they're widely sold and tolerated.
    – Chris H
    Commented Jul 12, 2021 at 10:31
  • 1
    The STVO in Austria says that you need at least 20 cm^2 of reflector surface on the sides of the wheels which puts a limit on how small a road-legal bicycle wheel can be. Though it’s not clear if the 20 cm^2 are for the combined area of all reflectors or just one wheel, one side. Interestingly enough a children’s bike only counts as such if the rim diameter is less than 30cm.
    – Michael
    Commented Jul 12, 2021 at 11:01
  • 1
    @Michael we have similar arbitrary rim diameters in legislation, such that some folding bikes are exempt from some routine requirements, while my tall seven-year-old's bike has to meet them all
    – Chris H
    Commented Jul 12, 2021 at 14:59

Here in Austria the STVO §2 says:

  1. Fahrzeug: ein zur Verwendung auf Straßen bestimmtes oder auf Straßen verwendetes Beförderungsmittel oder eine fahrbare Arbeitsmaschine, ausgenommen Rollstühle, Kinderwagen, Schubkarren und ähnliche, vorwiegend zur Verwendung außerhalb der Fahrbahn bestimmte Kleinfahrzeuge sowie fahrzeugähnliches Kinderspielzeug (etwa Kinderfahrräder mit einem äußeren Felgendurchmesser von höchstens 300 mm und einer erreichbaren Fahrgeschwindigkeit von höchstens 5 km/h) und Wintersportgeräte.

  2. Fahrrad:

a) ein Fahrzeug, das mit einer Vorrichtung zur Übertragung der menschlichen Kraft auf die Antriebsräder ausgestattet ist,

b) ein Fahrzeug nach lit. a, das zusätzlich mit einem elektrischen Antrieb gemäß § 1 Abs. 2a KFG 1967 ausgestattet ist (Elektrofahrrad),

c) ein zweirädriges Fahrzeug, das unmittelbar durch menschliche Kraft angetrieben wird (Roller), oder

d) ein elektrisch angetriebenes Fahrzeug, dessen Antrieb dem eines Elektrofahrrads im Sinne des § 1 Abs. 2a KFG 1967 entspricht;

DeepL translation:

  1. vehicle: a means of transport or a mobile working machine intended for use on roads or used on roads, excluding wheelchairs, baby carriages, wheelbarrows and similar small vehicles intended primarily for off-road use, as well as children's toys similar to vehicles (such as children's bicycles with an external rim diameter not exceeding 300 mm and an attainable driving speed not exceeding 5 km/h) and winter sports equipment.

  2. bicycle:

(a) a vehicle equipped with a device for transmitting human power to the driving wheels,

b) a vehicle according to lit. a, which is additionally equipped with an electric drive according to § 1 par. 2a KFG 1967 (electric bicycle),

c) a two-wheeled vehicle driven directly by human power (scooter), or

d) an electrically driven vehicle whose drive corresponds to that of an electric bicycle as defined in § 1 par. 2a KFG 1967;

What’s interesting is that it explicitly mentions scooters and considers them bicycles.

There is also a paragraph about reflectors and lights, which dictate 20cm^2 of reflector surface on the wheels (either as a continuous ring on the tyres or dedicated reflectors). It also says that you need reflectors on the pedals (or equivalent, I’ve seen this interpreted in the way that reflectors on shoes or crankarms can be used as well).


This is written from a UK perspective, but should apply to much of Europe, or be close.

Putting pedals on a scooter would make it a bike, if those pedals propelled it. But that would be quite a job, effectively re-engineering scooter parts to make a bad bike. Specifically for electric bikes, the pedals have to be usable when the motor is unpowered, reverting to a normal bike.

Folding e-bikes meet the niche you're looking to fill, though they're not cheap, but with custom parts and a huge amount of design effort your scooter mod wouldn't be either.

A related difficulty is that electric bikes (at least as sold) must be pedal-assist only, i.e. the electronics detect the pedals going round, and turn on the motor. E-scooters have to be throttle-operated as there are no pedals to detect. E-bikes with throttles used to be sold, and can still be ridden. I don't know about the legality of constructing one. Having ridden both, I vastly prefer the throttle, as I'm in control and don't have sudden acceleration when timing gaps in traffic; luckily I don't want a motor.

If you really want to build something like this (as opposed to buying something close enough), I'd still be looking to start from bike hardware, but it would be expensive. In the meantime there are 12"-wheel folding e-bikes for a few hundred pounds. They're probably pretty dreadful, but would still roll better on realistic road surfaces than scooter wheels

  • 1
    Excellent point on the wheel size. Smaller wheels are easier to store and carry, larger ones roll better. A 6" wheel on smooth new asphalt would be fine, but on an average street would be horrid. And suspension does not really help.
    – Criggie
    Commented Jul 12, 2021 at 10:57
  • 2
    @Criggie that's one of my issues with e-scooters. Combined with their maximum speed of 25km/h even small potholes become really rather dangerous especially in the dark or when you need to look behind you. As I reckon most people here have experience, overtaking traffic doesn't always allow slow, squishy road users the chance to avoid hazards.
    – Chris H
    Commented Jul 12, 2021 at 11:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.