Going Electric? Here’s Our eBike Primer

When it comes to making the switch to electric, there are a lot of factors to take into consideration. Needless to say, with the options available to new and experienced ebike riders out there, it’s at least as research-worthy as a bike purchase and probably more so.

In this omnibus blog post (which we’ll be sure to keep updated), we’re looking at the many factors you’ll want to consider toward your ultimate ebike purchase. We hope you find it helpful, and as always, we’re here to help answer any questions you might have.

Hub Vs. Mid-Drive. What’s with all the ‘hub’-ub?

The first major decision the budding ebike rider must gear up to is whether to go with a hub motor or mid-drive motor system.

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Hub or mid-drive ebike motor

A hub motor ebike is an electric bike with a motor on either the front or rear wheel hub. A mid-drive motor ebike is an electric bike with a motor installed in the bottom bracket of the bike. When it comes to choosing between these two designs in my opinion, it’s not a matter of one being better than the other. They don’t lend themselves to easy apples-to-apples comparisons.

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Rear hub ebike motor

In a nutshell, the difference between the two is where and how the “e-power” is applied to the power train and this has a good number of implications for the the bike, the experience of riding it and its long-term durability.

While mid-drive motors are housed within in the bottom bracket, applying direct support to the crank, chain and gears, hub motors are installed within (you guessed it) the “hub” of a wheel, and may be in the front or the rear wheel. While there are a great many new, cool and er, “different” ways to e-power a bike, these two types represent the industry standards.

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Mid-drive ebike motor

The first thing riders will notice between these two systems is the difference in the experience of riding them. While the mid-drive motor provides a relatively subtle and seamless boost to ordinary riding, front and real hub systems deliver a noticeable pull or push respectively.

The other big difference is that because hub motors are directly connected to the wheels that continue to turn as you coast or ride down a hill, some of them (BionX for example) have been designed to convert those rotations into regenerative power delivered back into the battery allowing for so called “engine braking”. Mid-drive motors, confined to the free crank and hub don’t provide this “regeneration mode” efficiency.

Another key difference is the way the bikes’ weight is distributed between a front-heavy front hub, back-heavy back hub and the fairly balanced weight  distribution of a mid-drive motor.

I’ll now take a more personal tack in comparing these two systems.

Hub Vs. Mid-Motor: My Opinion

Personally, I prefer the mid-drive motor design because it makes me feel like it’s working in concert with my pedaling rather than driving or pulling me. As such, I feel a bit more in control, and this relates directly to the design.  As the motor is now directly driving the chain which is threaded through the bike’s mechanical gear system, the mid-drive design provides a relatively seamless, synergistic pedaling and gearing experience which maximizes the output and range from the motor.

This manifests itself in two important ways that for me make mid-drive systems a winner; The added efficiency not only means the bike provides greater range and distance, but also more power when you really need it, say when climbing a tough hill.

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A hub motor on the other hand, creates a heavier wheel which can translate into a feeling of sluggishness.  With a mid-drive system, separate from the wheels, integrated into the drive train, and in a center position with a  low center gravity, it provides better weight distribution, balance and handling.

But to maximize the mid-drive ebike’s power advantage, it is important to know how to use its mechanical gears properly. For example, and just like with a standard bike, if you catch yourself in the wrong gear on a hill, you may find the motor gets bogged down from the sudden spike in required torque. The good news is that the learning curve on gearing on a mid-drive ebike is pretty flat. After a few rides, you’ll find yourself gearing like a pro, and once you’ve mastered the concept, you’ll love how seamlessly a it can work with your natural pedaling and cadence.

It’s also important to remember that because the wheels of a mid-drive ebike are free of any additional components they not only spin free, but they can also be easily removed when it’s time to change a tire or make repairs.

Another advantage of a mid-drive motor is the fact that by enclosing the bottom bracket and crank it better protects its essential components. Additionally, and because it’s not in the path of water, dirt, snow or debris kicked up by the wheels, the mid-drive motor is in a better place to stay clean and last longer.

Mid-Drive Drawbacks

There are a few drawbacks to mid-drive motor ebikes that buyers should be aware of. On top of the fact that they will tend to wear out the drive-train – the chain, cogs and rings – more quickly, mid-drive motors don’t allow for power regeneration, or so called “regeneration mode”. So there again, due to the fact that more is required of the motor, component and battery life may be reduced. As such, you may find yourself replacing your drive-train and cassette as well as your battery more often than a hub motor ebike. That isn’t to say this will necessarily ever happen, it’s just something to be aware of.

Some mid-drives are also a bit noisier than hub motors, but when you’re cruising on an ebike with the wind in your hair, you may never even hear the motor noise.

The great news for mid-drive ebike buyers is that many major brands now have lines on the market and they seem to be the most popular choice for a lot of the hardtail or dual suspension ebikes.

While the decision between a hub motor and a mid-drive motor system is probably the most important one an ebike buyer will make, the options certainly don’t end there. Now we’ll take a look at the hub motor systems to see what makes them tick.

The Push/Pull of Rear Vs. Front

Like front or rear wheel drive in a car, (and eliminating the snowy winter issue) it’s really a matter of feel.  Not surprisingly, on an ebike, the rear hub motor feels like a push from behind, while a front hub motor feels like it’s pulling from up front, and it is usually very powerful. But to help figure out which one is better for you (beyond trying them both, and finding out for yourself), it’s good to get to know some of the mechanics and physics of the systems.

Knowing that virtually all standard bikes already employ a rear wheel power train, we immediately see a balance of features and benefits for both. While rear wheel hub power more directly connects to your pedaling, a front wheel hub introduces an “all wheel” power system that combines your human power  on the back with electric support up front. The single biggest drawback of the front hub motor is that it can be difficult to handle when the path gets slippery, or in tight turns.  Before looking at the differences in depth, let’s take a look at some of the elements common to both ebike power systems.

Power Re-Generation

Similar to the way an alternator re-powers the battery in your car, some ebike motors allow you to recoup some power through the process of normal cycling. Switching into re-generation mode or using re-generative breaking, you can add compression, or resistance that both slows you down, and re-powers your battery. Again, this is similar to letting your car ride a low gear down a hill to save on brakes and power up the battery.

For some hub motor brands this can re-generate about 10% of power back into your battery which is a great way to save some power and keep you ebiking longer and for greater distances.  And of course, re-gen mode is a great way to save your brake pads.

If you are a rider that doesn’t get manual shifting, you’re not alone. If so, a hub motor may be perfect for you because it drives the wheels that don’t necessarily need to work with the bike’s mechanical gears.

The next question to ask yourself is whether or not you want throttle control.

Pedal-Assist Vs. Throttle Control

While some ebikes are “pedal-assist only” which offers you motor power exclusively when you pedal, throttle control-added ebikes have both, allowing you to hold down a button to move the bike and not pedal at all. Some riders may never use the throttle, but many people also love having the option. For example, when you’re stopped on a hill, (and we know how hard it can be to get going sometime) the throttle is a very nice thing to have to get you moving again. The throttle can also be great on a long stretch of road when you may want to give your legs a break from pedaling. Keep in mind that prolonged use of the throttle can quickly drain the battery and limit your range.

Will that be Torque or Cadence?

Another question I often ask my customers is how much effort they  like to put into their pedaling. The answer helps me determine if the person should go for a torque-sensing motor or cadence-sensing motor.

A torque sensing motor (available in both hub or mid drive systems) measures the amount of effort the rider is giving, and in turn gives a scaled response in power assistance. The harder you pedal, the more power you yield from the motor. As such, there is a bit of variation in motor power when you don’t pedal with the same speed or effort consistently. If you are an avid or experienced rider, a torque-sensing motor may be more up your alley because it is a more natural feeling.

Cadence-sensing motors offer power whenever there is movement or cadence in the cranks regardless of the effort or actual torque. As long as you’re pedaling, the motor will give you consistent power output so that you can pedal lightly or forcefully, it doesn’t matter. If you’re a novice rider or a rider with less leg power, a cadence-sensing system could be your best bet.

Once you’ve weighed the differences above and are closer to a decision on the type of ebike you prefer (and again, there’s no substitute for trying them out), you’re in a good spot to narrow your selection down by ebike brand. This is usually the point at which price comes into play, and there you’re most often comparing motor power and battery capacity.

Power

Ebike motors are gauged in Watts and generally rated at 250W, 350W or 500W and this. In Canada, the legal limit for ebikes is 500W, but in the U.S., the limit goes up to 750W. Wattage is of course the measurement of the motor’s power, similar to horsepower in car. The higher the number, the more powerful your motor is. But remember, the more powerful the motor the more battery capacity it needs.

Capacity

Battery capacity is also essential to your ebike buying decision. How far do you want to take your ebike and what kind of riding will you be doing? A battery’s capacity is measured by its voltage and amperage rating; when you multiply the two, you will get the total number of watt hours (Wh). For example, a 36V battery with a 11Ah rating will give you a total of almost 400Wh. A 36V battery with a 8.8Ah rating will give you about 300Wh. A 48V battery with a 11Ah rating will give you almost 530Wh.

And here’s where the math gets a bit more involved.

All ebikes have different assist levels. Say, for example you ride a 500W ebike and you have 5 power assist levels. When you’re on level 1, you may only be using 100W or a fifth of the motor’s total power. A 530Wh battery will power a 500W motor for at least an hour if you’re using the motor at its full 500W power rating or on the highest assist level. If you’re cruising on level 1, and only using about 100W, then a 530Wh battery should technically last you about 5 hours. How many kilometers or miles is that? Well, that would depend on your speed. If you average about 30km/h, then in one hour you would have traveled about 30km. In 5 hours of travel time at that speed you could go a distance of 150km.

Range is not only affected by the motor wattage output and the battery capacity. There are many other factors that can determine range. For a mid-drive motor system, the rider’s ability to use the bike’s mechanical gears effectively can also be a big factor in range. Other factors such as terrain, load, and even weather can make a difference.

The Wrap

So there you have it. If you’ve read this far in this fairly long post we can guess that you may be interested in buying an ebike at some point in the future. I hope through these pages that I have helped you understand what to look for in an ebike and helped you move a little closer to determining what type is best for you.

If not, or you still some questions, I invite you to come down to the Reckless Electric store to speak to me and take a look at the truly awesome selection of ebike brands we have. We’ll be happy to let you take some test rides to see what ebiking is all about and which types and models suit you best.

One last thing to remember when buying any bike, but particularly an ebike with all of its complex components and moving parts. Every ebike will need servicing at some point down the road. At Reckless Electric, we offer comprehensive service for all the ebikes we sell. We are friendly, flexible, and knowledgeable. That’s just how we roll!

Thanks for reading and Happy eBike Shopping!