Abe_Froman

So, this summer I got back into biking and bike commuting pretty seriously after a hiatus from around the time my wife became pregnant (daughter is 2.5 now). I've got a different job, and longer commute compared to the last time I was commuting seriously.

Long story short, I'm considering an E-bike to use for the worst part of summer. I really don't mind riding when it is scorching out...but when it's pushing 90 at 8am with high humidity....it sort of pushes the boundaries of professionalism as I do wear shirt/tie and we have no showers on site.

I never would have considered this at all until I saw a guy at a stop light on a 10 year old E-Bike. I zipped right along, and I honestly had a hard time keeping up on my commuter. He was doing 20+, or at least 20ish.

What is a typical range/speed for an E-Bike? What should I look for in general?

2old

Commuter and no big hills, hub motor system will be adequate. Now many questions regarding whether you want to DIY, how fast you want to go, how far and budget. There are other considerations, but those are the main ones.

Abe_Froman

It will definitely be DIY, likely on a steel touring bike with wideish tires...maybe 38mm. 24 mile round trip commute. Budget is somthing I am not knowledgeable enough about E-Bikes to venture a guess as to what it should be.

I did have a question about speed....it it true that in every state but California, there is a speed cap of 20mph? If that's the case, I might adjust things a bit and go with a slightly beefier bike, with front porteur rack and large baskets in back to serve as a utility/grocery bike as well.

Edit: I had no idea these could be so inexpensive. What kind of battery would you pair with something like this:

https://bmsbattery.com/ebike-kit/333...ebike-kit.html . I could build a wheel around it myself. I'm assuming all I would need is some sort of wiring/controller and I would be good to go?

speedy25

Your biggest expense will be the battery. The speed cap is in the controller. Sometimes it can be overridden but an adult on a typical 350w setup will only go slightly above 20 anyway.

-SP

Abe_Froman

I've been doing a bit of research...slow day at work. Looks like you're right..motors are inexpensive but the batteries get expensive real quick.

In terms of speed...just messing around with bike wattage calculators...I cruise on my commuter at around 17mph, likely at about 150 watts. Addidng 250 watts to that would be a total of 400, which should equate to around 25 mph without working any harder. Is this correct, or is the math more complicated than what I am considering?

2old

You would need the wheel built as well as controller, brakes with cut off, etc (look at a company like ebikekit to see everything). However, I have a 1000w kit (put 48V, 1000w into your ebay browser) which costs between $200-$250 for a complete kit minus battery and charger (look at Luna Cycle --- $350-$500 for battery and charger). If you want a more pedal-friendly system, look at Chas58's posts. Check your local laws to determine what's needed or hope that the "good doc" answers. First timer, avoid BMS Battery.

Abe_Froman

I can build the wheel myself, but I am a bit sketchy on the electronics. I should be able to figure out eventually how to set up what I want though. I am looking to do a significant portion of the work with my own pedaling, and have something light/inconspicuous enough that it wouldn't be ridiculous to leave the system on and go for an un-assisted ride. Am I correct in assuming that if I ordered parts overseas, that speed would be limited on the mechanical/power limitations of the system, rather than limited with software due to local laws?

I suppose 20mph with a loaded utility cycle would still serve my needs, but it just seems a bit silly in principle to build an E-Bike that I could beat in a race un-assisted.

2old

1) If you buy overseas, shipping costs add a lot to the price, so make sure you get all the parts the first time.
2) As above, look at Chas58 for a 25 mph system.
3) You can limit speed with the software, but it's mostly a function of motor size & speed and the controller output. If you're really interested, look at ebikesca's simulator.

Doc_Wui

This ebikeling guy on ebay ships out out of Melrose Park, IL. I bought his geared motor kit last year, figuring I could knock on his warehouse door if anything went bad. Cost me $199 with only the LED display. Now it's $155 or $200 with the LCD. The LCD may let you run 36 and 48 volts. I know the LED display is limited to a single voltage.

36Volt 500W geared motor

The 36V controller can deliver 20 A, but the motor seems limited to 18-20 mph. Might be a 240 rpm motor, but I plan to test it with a 48V controller soon. It's on a old steel frame Trek that weighs 55 pounds with battery. OK for bike path and I've had it for 15 months.

I built another ebike this summer using a bare 250W bafang motor from elifebike on a 700CC wheel. I probably should have bought a 700cc kit from ebikeling, to save time and maybe some money. I spoked the wheel myself, but the first set of spokes I bought were too long, so poof went $30. The 250W motor is only 6.0 pounds, 2 pounds lighter than the ebay motor, and it happens to run 21 mph (260 rpm) at 36 Volts.

The second bike weighs 42 pounds w/o battery, and I plan to use a 52 volt 6AH Luna Mini, which is only 3 pounds. It uses very little power (under 8 watt-hr/mile) at 14-16 mph, so I might see a 30 mile range. It has no torque though, being a higher speed motor in a big wheel.

.

J Boz

If you want to pedal keep it legal speeds it would be hard to beat something like a 12t mac.