Bike Forums - Is 250W not enough?

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The Trek Allant 8s and Raleigh Redux IE have always been on my shortlist. The first Generation Giant Quick E had a 16 speed drivetrain but they killed that. I don't think you can pay $4000+ to Trek, Giant, or Specialized and get a bike that won't get you up any hill that you can keep the bike straight on! Look at some reviews on e-bike review sites. Watch some videos. Back of the napkin calculations ... that way lies madness. Ultimately I bought a 750W+ mid-drive and built an e-bike with $5000 production bike performance for just over $2000K. BTW, yes, the Allants are stiff but they have 2.4" clinchers. 40psi even 30psi is possible for these tires. I personally would not bother with a Thudbuster but that's me.

Quote:

Originally Posted by NHKeith (Post 22392320)

power is force times distance which is what really matters. .

Nope.

Power is force times distance divided by time.

This is important, because it just means it will take you longer to get up that hill at lower power. Also keep in mind that because it is pedal assist, it is augmenting what you are already putting into it.

My wife can climb a 22% grade in Eco mode. She isn't a lot faster than me on a non-ebike, but is much more well-rested at the top. You will be fine.

OP - IMHO, there is no such thing as a 250 watt bike - unless you are using a 24v battery
assuming the smallest battery is 36v and the smallest possible controller giving 10amps continuous = 360 watts.

If you are a strong biker, you can do that on your own. So, do you want a heavy expensive ebike to take you to the top, or do you want to pedal a bike with e-assist.
If you can climb the hill on your own without a motor, 350 watts is plenty to assist you. if you give 250 watts + 350 from the motor you are at 600 watts.
If you want the bike to take you up there with minimal assistance - you probably want 1000 watts.

Quote:

Originally Posted by shelbyfv (Post 22392744)

Even a strong cyclist will suffer some on a 15% climb. So while a 250w motor might double your power, you still may not be able to cruise up the hills. Nobody ever has too much power so get the biggest motor you can within your budget. Also, a throttle will make hill starts much easier.:thumb:

I got the smallest motor I could, because I hate a 50lb bike - especially when I am climbing.

Quote:

Originally Posted by Polaris OBark (Post 22410815)

Nope.
Power is force times distance divided by time.

Well, I'm guessing he meant torque, which is relevant climbing a hill. Power has a time component like you mentioned, but I don't think anyone is trying to accelerate up the hill, we are just trying to climb the darn thing.