every once in a while, I see a person riding a bike that's powered by a motor. It will accelerate the bike really fast, and the bike will coast for a while, then repeat. And apparently, the rider can also choose to pedal if he wants. just curious are these things purchased? or do these people actually craft them from purchased parts?

There are things that should not be spoken of here.

Try googling 'motorized bicycles'.

https://www.ridleymotorcycle.com/motorbike/1903.htm

Try this very site , look under Electric Bikes, here in bikeforums.net. I've been thinking of adding an electric kit to my wifes bike.

A few weeks ago, I had an electric bike following me whilst riding on a city st. Speed was probably around 15 mph. The rider of the e-bike was a hefty gent. When we came to a small hill, I pulled away easily. Motorboy never could catch back up.

I'm not a particularly fast, strong or young rider. Motorized bikes have always struck me as novelties with limited practicality. The gas ones are to fast for bike paths and too slow for traffic. 1903 was not a great time for motorcycle design. Some of these bikes lack gears and a clutch. Stop the bike, stop the motor.

I use one on my Cervelo S2...helps me keep up on some of the climbs with the B groups.

Yes, I agree. Unless the "motor" is human power it doesn't belong on this forum.

maybe it's because i'm a flatlander living in that vast, useless expanse of land between the appalachian and rocky mountains, but putting an artificial motor on a bicycle just seems wrong to me.

though i suppose my attitude could change if i were to move to a place that actually had hills.

or maybe not. generally speaking, i'm a purist, and that extends far beyond the bounds of the world of cycling.

Missed this section? https://www.bikeforums.net/forumdispl...Electric-Bikes

There are electric assist bicycles, from many sources..
varies by state, but if the boost goes away
when you stop pedaling, it is still legally a bicycle.

If there is a no pedal but the motor runs adding power, anyhow ..

It can be construed to be a Motor Vehicle
requiring an operators license and perhaps even Insurance


there is the whole area of motorpaced bicycle racing,
Keirin, in Japan an example, that brings you into a Co-Op arrangement
between the fuel motorized and athlete powered bicycle.

The classic non-human-powered bicycle is velo-solex.

Cancellara recommends the Gruber Assist.

the way I seeit is the only bikes with motors should be like the ones in my signature lines. The little dinky motorized bicycles only give inexperienced (usually non-licensed) riders a chance to get run over on public roadways.

We have a forum specifically for electric bikes: https://www.bikeforums.net/forumdispl...Electric-Bikes

They are nice for those who need assistance riding, and they also make great utility bikes.

That's a point that I was going to make too.

I personally have no interest in such things because I think of bicycling as being an exercise and fun kind of thing. Consequently, my first thought was, "What's the point?".

There are those folks, however, who rely on bicycles for low cost day-to-day transportation and who have no interest in bicycling for exercise. I suppose they'd think that my collection of bikes is kind of dumb.

I guess that freedom requires us to tolerate both points of view.

Hey, look everybody! The website has a new owner!!!

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The engines are usually bought as kits, though some people do make them on their own.

There's a sub-forum here for electric bicycles, with a bit of info on gas-engine bicycles.
There's at least two other forums that are much better for info on gas-engined bicycle kits than here.

Motorized bikes can be a huge help if you need it, and lots of fun even if you don't.
Laws vary widely (at least in the USA, state-by-state) so you'd first need to find out what is legal and what isn't. Wherever you get license plates for your car should be able to tell you that.

...And even if no motorized bicycles are legal where you are, there are still,,,,, ummm,,,,, options.


?
Ummm,,, what do you think motorcycles started out as?

And as for riding in the street, some of us do that all the time anyway.

Theres the Stoke Monkey, thru Clever Cycles in Portland
but it only fits long tails like Xtracycles and Big Dummys.
because it mounts an electric motor where would be the rear triangle,
and drives a crossover second chainring on the left.

If I were the new owner, the mods would be instructed to ban anybody speaking of anything I don't embrace. Kinda like a New World Order. Or a Brave New Human-Powered World.
Neither me nor The Donald is likely to get elected the new owner of BF.

I've also often thought the world would be a better place if I were king.

Motors are to bicycles as hospitals are to the sick and injured.... you don't need them if you're healthy.

...And a lot of long-distance runners would probably say that you don't need a bicycle. They're expensive, delicate, noisy, a hassle to transport and all they really do is prove how lazy you are.

Above 12,000' on Mt Evans, I've been *dropped* by runners.
One of them even told me that it is an established fact that it is easier to run than cycle at that altitude.

Try this site:

https://www.motoredbikes.com/index.php?

And I disagree. Although some appear to be appalled at the idea of putting a motor on a bicyle for high moral reasons (or something), there is a whole bunch of folks who are tinkerers, build-it-yourself fans, motorheads, or whatever who like to fool with such things.
There are a wide variety of engines available, both four-cycle and two-cycle. They run economically, better MPG than your average "scooter".
Also, many of these self-produced bikes show high style and are often made to emulate early motorcycles.
Such things are just fun to build and run.