Folding bicycles have been around for decades, and in the last few years this versatile frame style has been applied to electric bikes. Folding ebikes are designed to fold into a compact form, facilitating transport and storage. When folded, the bikes can be carried into buildings and on public transport, making them idea for urban commuters and students. Folding electric bikes are also popular for those in compact living quarters or aboard a car, boat or plane. Before checking out our recommendations for the 10 Best Folding Electric Bikes for 2019, read this article to familiarize yourself with key folding ebike specifications.
New folding electric bikes come in a variety of styles, including standard full-size ebikes like the X-Treme Baja, lightweight sub-compacts like the e-Mazing B.O.B., fat tire folders for sand and snow like the Lynx Pro, and powerful all-terrain models for outdoorsmen like the BackCountry Stalker.
But before you buy a folding eBike, make sure to evaluate its component parts, and know its specifications (aka Specs). In this article we will discuss the most important components and specs to understand. After reading this article, you will be ready to choose from one of the 10 Best Folding Electric Bikes for 2019.
Folding mechanisms vary from model to model, but typically include a heavy-duty hinge and locking clamp at the center of the frame. The hinge will be welded to the frame and built from the same material, usually chrome moly steel or 6061 aluminum.
The clamp on a folding ebike is usually made from high quality aluminum. When the clamp is locked in place, the frame will be rigid and will not exhibit any additional flex at the hinge point. You should never ride a bike with a loose or weak clamp. Some models require the bike to be folded to access the battery, which is integrated into the folding bike frame. After every ride, the clamp should be wiped clean of any surface moisture or debris.
Sticking with the mechanical components of an electric bike, most ebikes come with a conventional drivetrain, which includes the chain, sprockets, derailleurs, cables and shifting triggers (a lever or button). While most ebikes have traditional exterior gears, there are a few that internally geared hubs, which do not have a derailleur. There are also a few ebikes that feature a carbon belt drive instead of a chain, which may be paired with a IGH and allow for a grease-free transmission.
Why do bikes have gears in the first place? Well, gears are there to enable us to maintain a comfortable pedaling speed (or cadence) regardless of the gradient or terrain — something that no one single gear is capable of.
The gears on your folding ebike can be used with or without the electronics. You can ride an ebike like a conventional bike, just coasting and pedaling, and engaging the gears to suit your riding. When you do decide to engage the motor - by either pedal assist or with the throttle - you can continue to adjust the gears to give you the perfect amount of resistance.
Folding electric bikes typically come with mechanical disc brakes, although some more expensive models feature hydraulic disc brakes. With mechanical disc brakes, when you pull the brake lever, it pulls a cable which will cause the caliper to grip the rotor, providing excellent stopping power. This is much improved over the older style V-brakes or cantilever brakes. With hydraulic disc brakes, the steel cable is replaced with hydraulic fluid, which will delivery even more stopping power than a mechanical disc brake.
A feature you will find on most ebikes is an automatic motor cutoff, which is triggered when you pull either brake lever. This is important, so that when you engage the brakes to stop, the motor will stop accelerating the bike.
Brake maintenance should be performed regularly, especially if you are riding your bike everyday. Make sure the brakes engage even when you only pull slightly on the lever. If there is some slack before the brakes engage, then you probably need to tighten up your brakes a bit. With mechanical brakes, you can tighten the cable by twisting a screw at the point where the cable enters the brake lever housing. In the case of hydraulic brakes, you will need to replenish your fluid, so that the brakes are highly responsive when activated.
All folding electric bikes will have a motor to power the bike, either by engaging the Pedal Assist System (PAS) or using the twist or thumb throttle. The motor is typically a DC brushless electric motor, which is highly efficient and long-lasting. The motor will be integrated into the rear hub, the front hub, on the bottom bracket (known as a mid-drive). The nominal output for a ebike motor will range from 250W on sub-compact ultra portable models like the Fairweather, to 1000W or more on some high end fat tire electric mountain bikes (e-MTBs).
When using the Pedal Assist System (PAS) to power the bike, you will pedal, and the motor will help you along. The higher level of PAS you set, the more power the motor will put out, and the faster you will go and the easier you will climb hills and ride against headwinds. This is true for the use of the throttle as well. The more power you demand from the motor, the more it will output.
The housing of electric bike motors is designed to keep the internal parts free of moisture or dirt, but they are by no means waterproof. Therefore, when riding your folding ebike, make to wipe off any water that may accumulate on the motor housing, and avoid soaking the motor in puddles, creeks or ocean waves.
The battery on electric bikes is one of the most confounding components for many new ebike riders, but it really isn’t all that complicated. Just like the battery in your mobile phone, the typical ebike battery is comprised of cells with primarily lithium-ion chemistry, with specifications for voltage and amp-hour (from which you can derive watt-hour).
Most folding electric bikes will have a battery and motor pair rated at either 36 volts or 48 volts. There are a few bikes with 52V systems, and beyond that you can see 72V systems used in do-it-yourself (DIY) setups. Voltage represents the electric potential difference, electric pressure or electric tension is the difference in electric potential between two points. A higher voltage rating will mean that more power can be delivered to the motor during the same increment of time.
The Amp-Hour (Ah) specification represents the storage capacity of the cells, and thus the potential riding distance or range you can expect from a full charge. Ebikes in the US typically have 10.4Ah, 11.6Ah, 14.5Ah, 17.5Ah, or even 20.0Ah or more. But you pay for this extra capacity. Regardless of the Ah capacity of your ebike battery, the range you can expect from a single charge will be affected by a number of factors, including terrain, weather, rider and payload weight, tire inflation, and riding style. Our recommendation is to get the biggest battery you can afford, and maintain it properly to extend the life of your battery.
Many of the questions I get from customers concerns the battery. Where are they made? Are they safe? How long will they last? Can replacement batteries be purchased? And so on…
First, let’s keep in mind that an ebike battery is made of of several components. There are the battery cells themselves, often from name brand manufacturers such as Panasonic, LG, and Samsung, but also from top brands with no name recognition in the US such as TH Brand. More important than brand name cells should be the ebike manufacturer, because they are the ones specifying the battery components and working directly with the Chinese factory. The cells are wired together and connected to the battery management system (BMS), which is the electronic device which regulates the flow of power into and out of the network of cells. So when you plug your battery into the wall to charge, you are actually activating the BMS, which distributes that charge to 48 or more individual cells within the battery casing, cutting them off as the reach full charge and providing feedback to the charger.
Much more could be said about batteries, but this article is focused on the key component specs for your next folding electric bike.
The controller is the simply the brains of your folding electric bike. The controller, usually mounted in a small box within or next to the battery case, controls all the electronics of your ebike. The sensors that monitor your speed and cadence send signals to the controller, as do the throttle and PAS control panel or display. The controller is also responsible for serving as the interface between the battery and the motor.
Controllers on ebikes are often no-name OEM products, and have a higher failure rate than electric batteries or motors. The good thing is that they are easily replaced by the manufacturer. This is another reason to select a high quality brand, so that you can rely on them to spec a good controller for your folding ebike.
The wheels on your folding ebike are going to be like the wheels on a conventional bike, with a metal rim for mounting the tube and tire, connected by spokes to the hub. The one main difference is that most ebikes will have an electric motor built directly into the wheel’s hub, whether it is in the front or rear of the bike. The wheels on an electric bike will spin on their axle just like a regular bike, and if the motor is not engaged, it will have no effect of the wheel (i.e., there is no drag effect of having a motor hub built into the wheel). It should also be noted that almost all ebikes on the market today do not include regenerative brakes or motors, so you will not be able to use the ebike motor as a generator to store power in the battery.
Folding electric bikes often feature 20” tires, and while the width of the tires can range from 1.75” to 4.0”, the fat tire format of 20” x 4” is widely popular. The fat knobby tires will cut through snow and sand better than a narrower gauge tire, and the tires can also have their pressure adjusted, from a low of 5 psi to a high of 30 psi.
One of the newer types of wheels found on folding ebikes are made from a magnesium alloy model, with rigid struts taking the place of steel spokes. The main benefit of having a molded mag wheel is that is does not fall out of true like a spoked wheel, and it provides lighter weight stability and stylish looks.
In the end, folding ebikes are very similar to conventional ebikes, and even conventional bicycles. If you would like to learn about all the folding ebikes we carry, check out our Folding Electric Bike Collection. And for our picks for the best folding ebikes on the market today, check out our recent article 10 Best Folding eBikes for 2019.