Which frame and ebike kit?

Gkyle840

New Member
I would like to build my second Ebike. I want to build something that I can ride unpowered when going on family bike rides but also something that will do 40+mph that I can ride on our local roadways to keep up with traffic if need be. I have my eye on a 1500 watt rear hub but am struggling to find a bike to convert. I was thinking something along the lines of a diamondback response or GT aggressor pro? I am 6'0 tall and I prefer to sit more upright so would likely need to raise the handlebars and get a wider set for any bike I choose. Are there any frames that work well that are under $400?
 

Gkyle840

New Member
I do want to ride without power. I don't know much about mid drive. Is it only better due to drag? If so how much more drag does a rear hub cause
 

AHicks

Well-Known Member
Not all "rear hubs" are created equally. Direct drive hubs DO have sometimes noticeable amount of drag when coasting/unpowered. Gear driven rear hubs are not only peppier than a direct drive, they also feature a clutch that decouples the motor when coasting or unpowered.

I would note that a bike of ANY type, is not going to go far at 40mph. Speaking in bike terms, there's a huge amount of air resistance at speeds like that (noticeable even as low as 15mph). To reach that speed (40mph), and hold it for any length of time, in most instances is not currently possible. The weight of the batteries required to do that would be prohibitive (as well as heat buildup in the motor) - ESPECIALLY when considering a bike to be ridden unpowered on family outings.

Reality check time......

As far as frame, any donor bike I would consider would have disk brakes.
 

Timpo

Well-Known Member
Not all "rear hubs" are created equally. Direct drive hubs DO have sometimes noticeable amount of drag when coasting/unpowered. Gear driven rear hubs are not only peppier than a direct drive, they also feature a clutch that decouples the motor when coasting or unpowered.

I would note that a bike of ANY type, is not going to go far at 40mph. Speaking in bike terms, there's a huge amount of air resistance at speeds like that (noticeable even as low as 15mph). To reach that speed (40mph), and hold it for any length of time, in most instances is not currently possible. The weight of the batteries required to do that would be prohibitive (as well as heat buildup in the motor) - ESPECIALLY when considering a bike to be ridden unpowered on family outings.

Reality check time......

As far as frame, any donor bike I would consider would have disk brakes.
Yes, direct drive hub will be far worse than geared hub drive because of direct resistance.
That's how Stromer can have this "theft mode" to lock the bike using motor's resistance.

But I was talking about physical weight.

I'm not an engineer, but I was at this motorcycle show, and Kawasaki engineer was explaining how weight distribution, and you can't just look at total weight.
Many people just look at the motorcycle's total weight.
In this case, ebike's weight (usually around 55 lbs to 65 lbs)

But that's doesn't mean much. He was explaining us about rotating mass, unsprung weight, mass damping, all that kind of stuff

Here are examples,

When you take off 20 lbs off the car's wheels (5 lbs each) you will feel dramatic difference.
The car will accelerate a lot faster, stops a lot quicker, etc.

Now, what if you take off 20 lbs off the frame? Do you feel the difference? NO.
What if you put 20 lbs weight in the passenger seat? No difference at all.

Same as motorcycles, if you take off 2 lbs off the wheel, you will feel a dramatic difference.
What if you add 2 lbs in your backpack? You will feel no difference.

No just machines (cars, motorcycles), you can feel it by using your body too.
For example, what if you carry a 10 lb backpack? Can you still run or walk normally? Yes you can.
What if you wear 10 lb shoes? Can you still run and walk normally? Not likely

Adding weights on "moving components" is a bad idea. That's why Yamaha mid drive ebikes feel like normal bicycle when it's underpowered, whereas Bafang hub powered ebikes feel heavy.
You have a big dead weight on wheel, that's why. (Sure, geared hub drive can have a clutch to disengage, but still, there's a dead weight that you have to rotate.)