I was given a bike with an electric rear hub. I'm mechanically inclined but I've never had the opportunity to tinker with one of these. I'm fairly experienced with AC and DC electronics as well. If anyone could help with where to start, I'd appreciate any advice or direction at all. Thank-you...

closed as too broad by RoboKaren, Argenti Apparatus, Criggie, David Richerby, ojs Aug 27 '18 at 17:21

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Gidday and welcome to SE. Good work for reading the tour page. Problem with this question is its very broad and that might be enough for it to be closed. Feel free to use Edit to describe the problems you're facing, and what troubleshooting+results you've achieved already. – Criggie Aug 25 '18 at 8:47
  • I've never worked on one of these, but there should be good manufacturer's documentation online somewhere, since bike shop mechanics need to service them. What sort of damage is present? – Daniel R Hicks Aug 25 '18 at 11:33
  • This isn’t the right forum unfortunately as you really need someone to walk you through this. I’d suggest endless-sphere.com/forums – RoboKaren Aug 25 '18 at 16:38
  • @DanielRHicks - not if its some random chinese thing from ebay (though those are often electric front hubs). This going to be something that is difficult to diagnose over the internet and probably doesn't fit the stackexchange format. – Batman Aug 26 '18 at 12:03

First thing to do is check all the parts are present. Without knowing your specific bike, you will probably have

  1. A bike - thing with two wheels, etc.
  2. Built into the bike will be a motor, probably in the middle of one wheel, but some designs have the motor between the pedals. Rarely, some use a rubbing roller to push the wheel, but these are uncommon.
  3. Battery - it should be fairly obvious.
  4. Charger - lack of a charger is a strong indicator that the bike might be stolen.
  5. Optional head unit / control panel - If the bike has one, it will likely be on the handlebars, and have some buttons and possibly a display or at least some LEDs for charge remaining.

Either in the battery pack or in the head unit will be a DC to AC converter. Many ebikes have a 24 or 36 volt DC battery, but the motor itself is probably an AC unit for efficiency.

If you're looking at resistances, expect megaohms across the motor, and that it has 3 or 4 wires going to it. You can't just connect the battery to the motor and have it go.

Make sure the battery is charged fully, then connect it, and turn on the bike. You may need a key or card to do this, and lack of this is another indicator of a stolen bike.

When it starts, read the display, look at the LEDs, listen for beeps, and any bad messages should be referenced with the manufacturer's info. This will be unique to the system, not necessarily the bike brand.

Modern ebikes tend to be "pedelec" meaning they give the rider an assist when pedalling motion is detected. Older bikes tend to be throttle based, where you have a rheostat or a simple button for "add power" Buttons are easy to troubleshoot, sensors are much less straightforward.

Other than that, its all getting very specific to your bike's electric system. More details could help.

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