Two-wheeler categories and definitions under law
Editor’s note: California cyclist and advocate Bill Sellin has produced the Venn diagram of two-wheeler categories below. It identifies how California traffic law treats bicycles, motorcycles and everything in between, with or without pedals. Sellinsuggests how his analysis can be useful in clarifying enforcement issues and in advocacy.
The same type of analysis can serve for other states.
Read the text below the diagram for Bill Sellin’s explanation. Also, see Kirby Beck’s series of articles on this site, which addresses how to reach out to local police. Clicking on the image will enlarge it for easier viewing.

Venn diagram of California laws for bicycles, motorcycles and everything in between
Bill Sellin says:
To sort out out two-wheeler categories — particularly among those with electric motors, it is important to use specific terminology that corresponds to the California Vehicle Code, not just marketing.
To help share the details, I have generated this Venn diagram to slice up the nuances of “e-bikes”
Feel free to share it with your local police, policy makers, schools, parents and any shops that sell electric vehicles as “e-bikes”…
The Green circle are BICYCLES (NOT VEHICLES) ; Purple are Motorized Bicycles = Mopeds; Yellow are Motorcycles (VEHICLES)
An electric bicycle, like a moped, has pedals with obvious assistance (in the red circle).
- If an electric bicycle has a throttle it crosses into the blue circle.
- If a bicycle has a throttle that exceeds 20 mph, it by default moves to the Moped puddle.
- If it exceeds 30 mph it is too fast to be a Moped and is thus a Motorcycle.
In California, the existing laws clearly require motorcycle helmets and motorcycle driver’s licenses and DMV registration…
DMV will not even register a vehicle without a VIN to certify that it meets the standards for road safety. It is legal to ride only on private property —
(like a race track – or your own back yard).
Vendors who sell them will take our money, call them “e-bikes” and never mention (if they even know) that they are illegal t on streets.
There is no such thing as a “Class 4 electric bicycle” and nowhere in the law is an “e-bike” defined…
I do not hold that there are “out of class” electric bicycles; they fit in one of the 3 puddles; Bicycles, Mopeds or Motorcycles; period.
Just enforce the existing local laws on Mopeds and Motorcycles and the streets will be safer for everyone..

Bill Sellin is a California cyclist and cycling advocate. He serves as a member of the Infrastructure Review Committee of the Orange County Bicycle Coalition and as Area Liaison to Caltrans District 12.