There are lots of barriers to getting started repairing eBikes. Many shops won't touch them. Others don't have the expertise.
Over the past few years I have gained a little experience working with eBikes. After fixing a few eBikes, I now think that it isn't that hard to understand them and work on them.
Local Non-Profit Rejects eBikes
My local bike non-profit does not accept eBikes. Officially the reason is that the lithium ion battery packs are considered fire risks and are not allowed by insurance nor by the building owner. Unofficially, I also suspect a neo-luddite fear and loathing of new technology. Many shops have no idea how to even get started with repairing eBikes.
eBikes are Here to Stay
eBikes provide low-cost carbon-free transportation. Not only should community bike shops deal with eBikes, we should embrace them as low cost transportation for the masses, particularly those who are elderly, weak, infirm, or must otherwise travel distances too long for them to negotiate by pedal power alone.
Going forward, community bike shops are going to see increasing numbers of older eBikes. People are going to offer them as donations to non-profit shops. We can stay stuck in our old ways and continue to ban them from our shops, or we can learn, adapt, and make eBikes part of our lives.
Besides inertia, the biggest problems to fixing eBikes are fear of new safety risks, and lack of trained eBike mechanics. Let's consider both of these.
Safety Risks
Should we even attempt to repair eBikes? eBikes present two types of safety risks.
First, batteries can explode and burn during charging or storage. Second, mechanics can be burned if they short-circuit an eBike battery. We need to consider how to mitigate these risks.
Battery Chemistry Risks
Newer battery chemistries have the potential to greatly reduce the risk of battery fires. LiFePo4 (lithium iron phosphate) batteries are much less prone to thermal runaway than lithium ion batteries with liquid electrolytes.
Solid state batteries are generally considered much less likely to burst into flame than current lithium ion batteries with flammable liquid electrolytes, but in the worst case solid state batteries can burn even hotter.
Need New Safety Procedures
The big risk of having eBikes in a shop or garage is thermal runaway in a single battery cell causing an uncontrolled fire that burns down the entire building. We need to adopt new safety procedures to minimize the risk in storing and charging battery packs. The National Bicycle Dealers' Association (NBDA) has some safety recommendations for lithium ion battery packs:
This article recommends storing batteries in a fire-resistant storage cabinet. It also recommends not charging batteries to 100% until just before the bikes are to be ridden.
I tend to accept the NBDA guidelines simply because it is a national business organization. On the other hand, companies that make special battery pack storage lockers claim that a normal "flammables" storage cabinet isn't good enough, and that you should spend more for their beefier lithium-ion battery storage lockers.
Shops should ask their insurance providers about any additional expense for insurance covering eBikes on the premises. Some insurance companies may have their own safety recommendations regarding the safe storage of hazardous or flammable substances.
Few People Can Fix eBikes
Lately, I have personally seen an uptick in the availability of broken but free eBikes. Nobody seems to know how to fix them.
Part of the problem is that there are so many different and incompatible designs. There are front hub drives, rear hub drives, and mid-motor drives. Parts from one bike are not likely to be compatible with another bike from a different manufacturer. The battery packs and motors may operate at different voltages.
Another problem is lack of repair information. I don't know of any manufacturer who makes freely-available electrical wiring diagrams of their products. A few systems perform startup diagnostics and display useful error codes, assuming that the system works well enough to display this information.
Some traditional shops won't touch eBikes at all. When I happened to visit my local commercial bike shop to get a headset part for an eBike, the mechanic was happy to give me some advice; however, he said (at least three times) that his insurance does not allow him to work on eBikes. He wouldn't even touch the headset on my eBike. Lucky for me, all I wanted was the missing part.
Learning to Fix eBikes
Fortunately, there is lots of hope. I have gained some experience repairing eBikes, and think that it isn't that difficult to diagnose and repair a large class of eBike faults. Here is how I got that experience.
Once, at Burning Man, someone asked me to install an eBike conversion kit to their conventional bike. Then, various friends asked me to troubleshoot their broken eBikes. Recently, I was gifted two different broken eBikes by fellow bike mechanics who couldn't deal with all of the wires and inscrutable electronics and mysterious controllers.
I managed to fix all of these bikes. In doing so I learned that many eBikes can be easily repaired if you arm yourself with a voltmeter and learn a few facts about how eBikes work. Then you employ the same repair skills that car mechanics and computer programmers use: observe, modify, and test.
If you're still intimidated by the thought of poking around in an eBike, try to draft someone to learn about this and possibly become your shop's lead eBike mechanic. Look for someone who knows something about bicycles and computers. It is good if they have an electronics multimeter, a soldering iron, and some general electrical troubleshooting skills.
For me a good source of information on eBikes is YouTube. There are several excellent videos that explain the basics of how to repair eBikes. The basic components are a battery, a motor, a throttle and/or pedal sensor of some kind, a display, a charging system, and a whole lot of wires. Many eBikes have a cutoff switch that disables the electric motor whenever the brakes are applied.
You Can't Fix Everything
It will make eBike repair a lot easier to contemplate, after you understand that you are not going to fix every eBike that comes to you. These things are complicated, have poor documentation, and lack troubleshooting guides. All you can do is to apply the basic repair techniques that you do know, and see what happens.
To Be Continued?
I had planned to describe some specific eBike faults that I discovered and fixed, but this is already getting too long. It might continue in a separate thread, or perhaps I should propose an eBike repair session for the next Bike!Bike! Perhaps I am completely wrong and most shops already know how to fix eBikes.