Electric Bike – DIY Life Guide

What problems do electric bikes have? Item need fixingBattery Terminals meltedController shorted outBolts came off back wheelThrottle BrokeWires meltedBattery holder brokeCost to fix$10$54$15$25$5$5Numbers come from my experience What is the lifespan of an electric bike? Electric bikes can last a lifetime with proper maintenance and part replacement. The most expendable part of an ebike is the battery which can fade in storage over time. Batteries should be replaced every 5 years. The controller is also very sensitive and will need to be replaced occasionally. Are electric bikes high maintenance? Electric bikes can be easily maintained for a low cost. Over time the bike will need to undergo the same tune ups a regular bicycle will require. Below are 6 common problems with an electric bike components specifically. These will be common problems that will happen in electric bike kits that have been added onto a bicycle frame. Some of these problems won’t happen with factory made ebikes. Inferior pin tab terminal https://youtu.be/1gkOTmHcxKU #1 Problems with an electric bike: Terminals on my battery melted My bike kit was 1500w rear hub engine matched with a 52v 17AH battery pack. The terminals on the battery pack were cheap iron taps that slid into the battery holders iron tabs. The connection of these iron tabs is what transmitted energy to the engine. These metal tabs were too thin and prone to melting when exposed to higher voltage than it was designed for. My 1500w engine was very powerful and drew more energy than these cheap components were able to handle. Xt90 pigtail I melted my first set of terminals that came with the battery. I then replaced these terminals with identical replacement terminals which also melted. After the second failure of the battery terminals failed I knew I need to upgrade the terminals that could handle more voltage. I decided to upgrade to high voltage gold plated Xt90 pigtails that would be heat resistant and more durable. How I fixed it Before starting flip the switch to shut off the battery. To complete this process I took the battery apart and unsoldered the old terminal from the wires connecting the cells. I then re soldered the higher voltage xt90 pigtail on to the battery pack. To finish I cut a hole in the side of the battery pack for the wire to go through. Then I completed the same process for the terminals on the battery pack holder. I unsoldered them and pulled out the wire. The wire runs from the battery pack to the controller. Instead of running the other side of the xt90 pig tail through the battery pack holder I let the wire run free and zip tied it to the frame of the bike. The allowed an easy connection between the pigtail that was coming out of the battery and the pigtail that runs to the controller. The battery would fit on the battery pack holder as it did before but the wires would be sticking out of the side of the battery. The wires from the controller were zip tied to the frame and ran to the pigtail on the battery. The xt90 pigtails are designed for much higher voltage and are durable to overheating and shorting. They are a better choice to ensure the longevity of usefulness of your battery. #2 Problems with an electric bike: Controller shorted out A very common problems with an electric bike is the controller shoring out. If the electric bike won’t move when you turn the throttle or it moves slightly and stops that is a common sign that the controller is the culprit. You may also see the wheel spin backwards as well. If anything is acting funky usually its a sign the controller has fried out. The controller is the brain of the bike and controls the components of the bike. Controllers are built in China and the quality of them can vary. First configuration of ebike. Battery on back rack. Bike controllers will usually short out for a few reasons. If the bike crashes or goes over a bumpy patch the sudden shaking can do damage to the controller. If the controller gets too hot it can cause damage. As pictured above I originally had my controller stored in a bag which did not allow proper ventilation and caused a short. The components of the controller are sensitive and can also short out if exposed to to any water. Usually the controller casing with have water sealing protection but there are no guarantees if the controller encounters heavy rain or complete submersion. Controller on rear rack How I fixed it There are not a lot of fixes for a shorted controller as its usually cheaper just to buy a new controller than hunt down the shorted pieces. To make sure the issue is with the controller and not another component of the bike you want to open up the controller. Put your nose over the open controller and if you smell a burnt smell then its official your controller is fried. Get same brand parts Order a new replacement controller with the same brand of your other components. You don’t want to order a “universal” controller that is off brand because there is no guarantee it will be compatible with the other components of the ebike. You also want to make sure you rearrange your bike so that your controller is out in the open and attached to metal as a heat sink. After my controller shorted I mounted my replacement controller to the metal rear rack so this rack could act as a heat sink to keep the controller cool. #3 Problems with an electric bike: Bolts came off back wheel Most electric bikes that are built from a kit will add an engine and battery pack to an existing bicycle. Regular bicycles are not designed to withstand the speed and rigor that an ebike will endure. One of the most common problems with an electric bike is that the nuts on the back bolt will unscrew with the additional speed. If your nuts come off the bolt there is nothing holding the wheel to the frame. This leaves you open to the wheel coming off while you are biking. Obviously the wheel coming off is very dangerous and could cause injury and damage to the bike. How I fixed it I bought a torque arm conversion kit and installed it on the rear axle of the ebike. The torque arms are installed on both sides of the axle to hold the wheel to the frame. These arms stop the nuts from unscrewing and will hold the bike together in the event of a nut unscrewing and falling off. The kit will include the adjustable tightening band, torque arms and hardware needed to install. The nuts will be held in place no matter how fast you go. How to install torque arm To install the torque arm unscrew nuts off the rear axle. Slide the torque arms over the rear axle in the hole. Attach the tightening band through the hole of the torque arm and wrap around the frame of the bike. This connection to the frame is what holds the wheel in place. Do this process on both sides of the wheel. Finish the install by screwing down nuts on the rear axle over the torque arms. #4 Problems with an electric bike: Throttle broke Most throttles that come with bike kits will be twist throttles similar to a motorcycle or dirt bike. Some may prefer these throttles but I found my throttle was easily broken. The throttle was made of plastic and the spring mechanism inside deteriorated with use. After a while the twist throttle broke entirely. How I fixed it I unscrewed the old throttle from the handlebar and detached the quick connect from the controller. This ill need to be replaced with a new throttle device. I personally prefer a thumb throttle accelerator as I feel they are more comfortable, safer and more durable over time. If your bike doesnt already have it I would also recommend a pedal assist sensor that will make it easier to accelerate by pedaling without a throttle. Make sure to order replacement parts that are compatible with the bike kit. #5 Problems with an electric bike: Wires melted and shorted out Depending on the brand of kit you purchase it can have varying quality of wire insulating and shorting protection. These wires connect the controller, battery and motor. Do electric bikes overheat? When the ebike is running at full power the wire will become hot and the wire insulation may melt off. If 2 wires next to each other melt it will cause a short circuit and the bike won’t work. You will smell a plastic burning smell and should be able to identify where it is shorting out. Wires melting is one of the most common problems with an electric bike because the voltage is so high. How I fixed it The wires may have become unattached may need to resoldered onto the connections. If there is any soot on the wire from burning or melting than it must be cleaned off. Only a clean wire with a clear connection will transmit electricity. The soldered areas and all exposed wiring need to be thoroughly wrapped in high heat electric tape. Wrap any other areas that are heating up. The electric tape can withstand temperatures much higher that the wire insulation. #6 Problems with an electric bike: battery holder broke Where to place the battery on an ebike is a tough choice. Misplacement can cause problems with an electric bike by threatening the battery. The weight of the battery means the only option is attach it to the frame of the bike. My original design of my bike had my battery mounted to a rear rack over the back tire. I mounted the battery on the rear rack because the frame of the bike didn’t have space. The problem with holding the battery on a rear rack is that the battery is very heavy and this will wear on the rear rack causing it to eventually fail. I was going very fast and hit a bump and my rear rack snapped right in half with the weight of the battery. I needed to bite the bullet and modify the battery holder so it was attached directly to the frame. How I fixed it I needed to place my battery in the center of the frame of the bike. This was a problem be because the battery pack holder was too big to fit in this space. The battery slid into the battery pack holder to be securely attached to the bike. There were two holes in the frame of the bike where screws would screw in for the water bottle holder. I used these screw holes to insert screws that would hold the battery pack holder. To modify the battery holder I took it apart. I drilled holes through the plastic and metal part of the battery holder so it would fit for the screw holes on the frame. After drilling the holes I screwed in the screws into the frame of the bike to attach the battery holder. I also used adhesive on the screws to make sure they stayed screwed into the frame. After it was screwed in I put the batter pack holder back together and slid the battery onto the holder to test it out. More resources: https://www.ifixit.com/Guide/How+to+Repair+Electric+Bikes/75971