Seen an old autocycle - when is a bicycle a moped?

[cbrtrxtdmvfrD...]

At the risk of getting a yawn irrelevant posting but curiosity has taken me over - On my way to work this morning (from Tavistock up across the moors to Hatherleigh) i came across a chap riding what looked liked a very old bicycle (no helmet just a bobble hat). Thinking to myself this chap must be seriously fit, he was riding bolt upright and in excess of 25mph without even turning the pedals so as i passed by i glanced at his bicycle and now all had become apparent - it had some sort of tiny combustion engine mounted on the frame, it was making a racket but not too much of one and it looked like Del boys delivery bike from Open all hours - very bicycle like, not at all moped like. This led me to not only thinking that "when is a bicycle not a bicycle and is a moped" and how does that compare with the fat slob who overtakes me on my own mountain bike going up Horrabridge hill on a Sunday morning because she has bought one of those £700 rechargeable modern electric bicycles and is her idea of exercise?
____________________
Right' O

[G]

Any internal combustion engine and it has to be road registered - numberplate, tax, insurance and helmet.
You can buy bolt on kits for not much, but they're not legal.
In days gone by you could get front wheel kits to motorise a push bike - these should come with a numberplate.
If your motor is under 1kw I think, it doesn't have to follow nearly as many regulations for MSVA I believe.

Electric push bikes are legal to be used the same as a normal push bike up to 250w. Over that, the rules are the same as if it was an internal combustion engine. However some do blag it, as there's little noticeable difference - a couple of people have asked if my electric push bike had a drum brake. Had some strange looks when going up a steepish hill on it at a reasonable speed with dogs running next to me .

[cbrtrxtdmvfrD...]

Great explanation - i understand many thanks
____________________
Right' O

[Baffler186]

Also an electric bike mustn't exceed 15mph under it's own power. Which is a bit silly, as you can go 40 mph down a hill while free wheeling.

[Northern Monkey]

My dad has a collection of 3 or 4 from the 50s.

If you can get a pre-'60 version, they don't need an MOT, tax is free, and insurance is only a few quid.

They're nearly all 2 strokers, and go about the same speed as someone who is fit riding a modern road bike.

They're also an 'M' class vehicle, not A, so all pre 2000 car licence holders can drive them with no CBT and no L plates