Your ebike motor breaks and no local bike shop will touch it. How do you get back on the road?

Step 1: How to Get Into This Fix in the First Place

The ebike revolution is rolling along nicely, supported by an increasingly robust ecosystem of component suppliers, bike designers, and knowledgeable retailers. I bought my first ebike in 2012, the only model sold by the only local store selling them at the time. The manufacturer went bust, as most early manufacturers did, and when I needed a replacement battery a few years later the supply of that peculiar type had all but dried up. (A good friend talked me into building my own battery, an unsuccessful effort but an important harbinger of repair jobs to come.) There was nothing my local bike shop could do for me then. Lesson 1: If you're not buying a major brand, you may find yourself without support further down the road.

I bought a second ebike in 2019. By that time many local shops had ebikes in stock, but none of them sold a bike I wanted (to spend that much money on). I ended up buying an Amego Infinite from a well-established vendor in Toronto, far from where I live. Though I did not realize it at the time, this meant that getting the e-parts of my ebike serviced would require shipping those parts to Canada: you are unlikely to find a shop willing to work on that part of a bike unless they sold it to you, or at least carry it. Bike shops are perfectly justified in this: every piece of electronics and every motor has its own peculiarities, and no repair customer is going to be willing to pay for the hours required to learn how to repair a novel system. Lesson 2: If you aren't buying local then regardless of the brand you're probably going to have to fix your ebike yourself.

The pandemic ended my bike commute and for some months my ebike sat in the garage. Eventually I realized I wasn't going to be commuting again anytime soon, so found another use for it: I live near open space full of trails and fire roads, so I put knobbly tires on the Infinite and began exploring the beautiful but rocky roads hereabouts. This took a toll: sprung spokes, leaking front fork, and eventually a broken motor. Lesson 3: If your bike wasn't built for the specific type of riding you're doing, it's going to break.

With a broken bike and no one to fix it, I turned to the Internet for parts and advice. There I found people who had the same bike model, similar problems, and a wealth of experience, sometimes all in one. My DIY friend had moved far away, but these people gave me a sounding board and some virtual company as I puzzled my way forward. Yet even with the help of their advice, it proved impossible to find a replacement motor (the easiest possible solution) and in the end I had to break my motor down and fab my own replacement part. Lesson 4: Expect to get your hands dirty.

You can take these lessons and ride off or dig into the details, below.

Step 2: Backing Into the Repair

The Infinity has a throttle, which is useful for making a fast start at a stop sign, but isn't really meant to be used to goose the bike up a steep, overgrown path. That's what I was doing when suddenly the motor stopped pushing. It was still going--I could hear it spinning--but somehow that spin wasn't getting to the wheel. And so ended that ride.

At the time, the internals of an ebike motor were a mystery to me, and not one I was particularly interested in exploring. The bike wasn't under warranty and I figured the motor was shot, so I tried to find a replacement. Between the original US manufacturer of the Infinity and the Canadian vendor who sold it to me there turned out to be a single replacement motor in stock, a 500w version, but one that should fit into the hub, thus saving me the cost of having someone build a bike wheel around it. Fortunately (as it would turn out) that one motor went to someone else, who discovered that due to a small change in its design it did not in fact fit into his hub and thus wouldn't have fit mine either. He ended up buying a whole new wheel with the motor built in. I tried to as well, but mysterious shipping issues arose and I never did get my motor. That cost me months but not money.

If I wasn't able to replace the motor I had no choice but to repair it. I'd already pulled the motor from its wheel housing but there wasn't anything visibly wrong with it. Perhaps a component I couldn't see had failed? The only obvious candidate was the clutch, a metal disc with, I assumed, complicated bits inside, and the sort of thing you hear about slipping. Replacements were cheap and easily obtainable online so I ordered one, plus the gear puller I'd need to get the old clutch off. These items having arrived, I pulled the clutch and in the process discovered that the pin that holds the clutch and planetary gears in place relative to the axle was in two pieces (light and dark, pressed together, as shown here).

Step 3: On the Road Again

As a temporary measure, I tried superglue--you never know--while I began my hunt for a replacement pin. The glue was useless (does superglue ever actually repair anything?) and the motor manufacturer confessed that this little bit of metal wasn't a standardized part, just something they whip up at the factory. They were willing to send me one, but I felt sure I could find or make a piece to fit that slot (and probably a sturdier piece at that). This I did (it's the shiny bit of hex wrench sitting in the slot above), and that stopped the motor from slipping. Again, much time but very little money.

In retrospect what surprises me is that this magic technology is so simple. The ebike motor is made up of a few discreet parts, each of which is separately replaceable. Yes, those parts, and their connections to one another, can fail in any number of ways, but the process of elimination goes quickly when there's only a few things to consider. So, as I've written elsewhere, keep your hands out of your battery, but don't hesitate to dive right into that motor: it may well be the fastest way to get back on the road.