# Power motor for a bike without pedaling

Hey guys!
I have a question: I am building a miniScooter and I must choose a motor for this. Neglecting the speed that should have, how much minimum power must have to move a person of 90 kg? I'm basically building a bike that moves by itself without pedaling and I would know what is the minimum power required to move a person with a weight of 90 kg. Sorry if I am vague and imprecise. Has this motor enough power? >> http://www.ebay.it/itm/191802708536?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Please help me xD

I have seen that an e-bike has a motor with power greater than 250W so this motor would be perfect for my scooter. Correct me if I have wronged.

The speed is everything when it comes to knowing what power.

Power goes up with the cube of speed once air-resistance becomes significant, although
its a more linear relationship at low speeds.

ok then 3.5 m/s max velocity for example

Mark is absolutely right.

Reminds me of when I had an old two stroke scooter.. Would go 60 km/h.
I replaced the exhaust with a high flow, advanced the timing , installed a larger diameter piston, and brought up engine rpm.

The engine put out probably 1/4 more power..awesome!.. Top speed 65km/h.

Having been on a few 250w scooters /bicycles.. 250 watts will get you there slowly under its own power (15-20 km/h) but is more of a "Pedal Assist" for travelling over 30 km/h.

Human legs can put out around 250watts too. Or 400 watts for trained cyclists.

Depending on the gearing and the speed required just about anything will move a person.

3.5m/s is a reasonable speed with 250 watts. Depending on driveline efficiency/ tires etc. It will get you moving at a good pace for sure.

Once you start feeling the wind on your face that will be your upper limit.

Thank you for your answers guys.
Let me explain: since I want to save money, I would buy a sufficient engine power to move without pedaling and especially without breaking the motor XD. Since I have never worked with these engines I wanted to know what was the minimum power that must have to allow me to move, even if the speed is relatively low. I informed: a bike is defined e-bike (moving alone without pedaling, like scooter) if it has an engine power greater than 250W. Since my scooter is much lighter than an e-bike like that I think 250W is enough power for my engine. If then with 250W can also get a speed of 3.5m/s then it is perfect! *. * What do you think?

This is the motor that I would buy >> http://www.ebay.it/itm/24-SCARICA-250-WATT-ELECTRIC-E-MOTORINO-MOTORE-24v-250w-/381481891685?hash=item58d217b765:g:x1AAAOSwBLlVcco6
Do you think that it is good for my needs?

That motor would do just fine. You won't be going up hill very fast but will easily hold 3.5m/s on flats if its just powering a regular road bike batteries and your 90kg.

Thank you so much