OVERHEATING AN E-BIKE CAN BE A BUZZ KILL, LITERALLY

OVERHEATING AN E-BIKE CAN BE A BUZZ KILL, LITERALLY

Too much load on an e-bike motor can get it hot enough to trigger an error code that will usually trigger a fail safe mode. It’s one of the most common problems people find with budget brands. Truthfully, the majority of the bikes that can experience this issue are hub drive systems. Simply knowing what the realistic capabilities of a hub-drive are will help you know if one is right for you. 

 Dealers are getting a taste of a momentum in sales they’ve never experienced as the e-bike segment rapidly expands. Therefore, the more informed you are the better chance you’ll make the right purchase for your style of riding. Getting most dealers to tell you what they have isn’t right for you is a long shot. 

On one hand you have the consumer’s responsibility to be honest about where they live or ride the bike. For example, if a heavier rider lives on a steep hill, they may need a different e-bike than a 90 pound 4th grader. Then again selling e-bikes is a business like any other. Ultimately, the more informed you are, the better chance you’ll have to get the right bike. 

Hub-drives are found on so many bikes these days and have proven to be a success for the majority of people.

POINTING THE FINGER AT HUB-DRIVES

Electric motors similarly to combustion engines struggle to dissipate heat as more load is applied. Load, in the case of electric bikes, comes almost exclusively in the form of hills. Steep hills can be too much effort for the average 250 Watt hub-drive to handle without any assistance from the rider. Some bikes do have more powerful motors, even up to 750 Watt in many cases. However, they’re mostly used in heavier bikes which somewhat offsets the gain in power. 

250 Watts is enough power to comfortably propel a 50-75 pound bike and its rider on flat ground until the battery runs out. Hills are a different story though and in extreme cases hub-drives can only handle a couple minutes before an overheating error can stop you. Most companies use a fail safe error code that will put you in a limp mode or just cut power till it cools down. 

If you bring your bike to the point of an error too many times, you run the risk of wearing the motor and other components out much faster. Usually the insulation around the copper coils that make up the bulk of an electric motor is the first thing to breakdown. As more load is applied at lower speeds, the more the other components start to breakdown. Sections of the copper windings will also start to char after a while.

As a general rule, the more you can feel resistance on your legs the less the motor has to work and potentially overheat.

DON’T EXPECT A FISH TO CLIMB A TREE

Hub-drive systems used on cheaper e-bikes do not utilize advanced technology that is available. Often, basic electric motor and sensor technology used doesn’t lend itself to the demands of steep hills. The basic technology we’re referring to is sold in the majority of e-bikes ranging from about $1000-$2000. 

You can usually look at the rear hub of one of the bikes in that price range and see a Bafang stamp on it. Bafang is a Chinese company that produces a massive amount of electric motors for the majority of hub-drive bikes. They’re more impressive than you may think though, and we’ve even heard of Bafang motors with over 30,000 miles on them. So, how they’re treated is the key factor. 

The number of mid-drives that have overheated are almost unmentionable in comparison to hub-drives. Mid-drive e-bikes are known for being able to hold their own on rides with massive elevation gains. It doesn’t mean they don’t get really hot though. If you’ve ridden a mid-drive bike, you’ve probably felt how hot it can get at the top of a long climb. However, with the newer generation motors we’ve heard of only a handful of overheating errors in the past few years. In just about every case it was an extremely long climb on turbo mode just trying to let the motor do all the work and often a heavier rider.

Mid-drive e-mtbs like this Husqvarna with a Shimano EP8 are known for being able to climb until the battery runs. out.

TIPS FOR KEEPING IT COOL

Often hub-drive bikes have a throttle which is overused in general, but particularly on steep hills. It doesn’t take long for error codes to present themselves when used in that way. Spending $2000 on an e-bike doesn’t make it a motorcycle. Therefore, actually putting more effort into pedaling up hills will be the best error code prevention. Not to mention add some life to the system overall.

Shifting knowledge is one of the most crucial things to know when it comes to riding hills. Many people are getting back into riding with the help of e-bikes. If you’re one of those riders, you may not even be familiar with modern shifters and how they work. You absolutely must understand how to use them via your dealership, friends, or YouTube because it will change your riding experience for the better. 

Being in a gear that allows your legs to spin at a relatively high cadence will give you the best chance of helping the bike get up hills. Cycling science tells us that it is easy to put more power out at a higher cadence. In other words, try to spin your legs a little faster as opposed to a little harder. As much as you can, try to feel a bit of resistance on your legs when climbing. If you are getting too tired or sweating more, then take a break.

Like we said it doesn’t take long for most hub-drives to get warm on steep hills but they do cool down quickly. A 2-5 minute break is a fair amount of time to let it get back to proper operating temperature. If you start to get errors on flat ground with minimal load you may have a separate problem which you should consult a shop about. 

FINAL THOUGHTS

Usually companies don’t tell the whole story when it comes to the potential of their bikes overheating. One company we won’t name says that it’s possible to overheat your bike in extreme conditions like, “the peak of summer heat”. Sure it’s the truth, but not the whole truth. In reality we hear of this happening to people on a weekly basis. Many people figure it out and quickly adapt their riding, while others are left angry that their machine doesn’t do what they thought it would. 

Hub-drive e-bikes are sold in mass quantities and this article isn’t about throwing shade on them. Truthfully, their benefits outweigh this one weak point, but it’s important to know about before buying one. All e-bikes whether mid or hub-drive come in many different styles, quality, capability and price ranges. Do the research and take your time in deciding which bike is best for you.