are power bikes safe?
what kind of maintenance is required?
Aside from keeping your battery charged, maintaining a Power Bike is the same as any bicycle. After the bike’s been ridden about 100 miles you’ll need a basic tune-up. This is standard procedure for all new bikes as they’re broken in.
How fast will they go and what kind of range will they get on a battery charge?
Our Power bikes will have a maximum assisted speed of around 40 mph and from 12-90 miles depending on the battery, terrain, weight, and level of pedal assist. Charging time is between 2-6 hours.
Is the motor loud?
Power bike basics, How does the voltage work?
That is a pretty simplistic way of putting it but it is the closest analogy to a car.Electric bike batteries typically come in 24V, 36V, and 48V batteries. More volts = more POWER.
Here is another analogy: electricity is water. If it is water flowing through the wires (tubes), then higher voltage means that the water (energy) moves faster, and through a smaller tube.
Amp Hours (ah) = The Gas Tank
“Your mileage may vary” is the car terminology for average miles per gallon, but I think that crosses over to power bike range claims as well!
What will affect the bikes range?
What power assist setting you are using? Most power assist bikes have several assist levels. Our Power bikes have a throttle that you can vary the assist with. This is pretty common sense, but the more assist you use the less range you will have.
Are you climbing a lot of hills? Range will go down.
Are you riding into a lot of headwind? Range will go down.
Are you carrying heavy cargo on your bike? Range will go down.
Some bikes may have a very inefficient motor (lost energy in the motor due to friction, etc.) that causes decreased range, but these days most power bike motors are fairly efficient (there is room for improvement!)
What is the condition of your bike? A well adjusted bike goes farther i.e. well lubricated chain, proper tire pressure, etc.
What is your tire pressure? Lower pressures = less range. There is a nice balance between too high a pressure (not comfortable) and too low a pressure (not efficient). 50-60 psi is a good pressure range for street riding.
Are you pedaling at the right times? Pedaling at critical moments (when accelerating or climbing), you will go farther.
Pedal more => More range and healthier for you
If you are concerned with range I recommend going with a large capacity battery pack. Some power bikes use a standard 10 ah pack with an option to upgrade to say a 15 ah pack.
What are watt hours?
Basically it is the the combination of the volts and amp hours to give you the total energy in the battery pack.
You may see this in the specifications for a power bicycle but it is not as common as the volts and amp hours specs.
Volts x Amp-hours = the amount of energy in the battery, or watt hours (WH). It is a way to compare batteries of different voltages or AH ratings.
Bike #1 has a 24 Volts and a 20 AH battery = 480 watt hours.
Bike #2 has 48 Volts and a 10 AH battery = 480 watt hours.
Both bikes have similar energy on board. And if they have roughly equal motors and riders, they will probably perform in a very similar fashion. The higher voltage bike may accelerate faster and climb better – at the expense of some of that energy.
Another bike has 24 Volts and a 6 AH battery = 144 watt hours. That bike is not going to go nearly as far as the other two.
How do I care for my lithium Ion Battery?
1. Owners Manual – Read and follow the owners manual and warning stickers supplied with your bike.
Explain braking as related to a power bike
Explain the terms used in Power Biking
- POD (Power on demand): On an power-bike with POD control, the speed of the motor is controlled only by a throttle. The rider may still pedal, but it is not required to pedal to activate the motor.
- PAS (Pedal assist): In contrast to POD mode, pedaling activates the motor. Some systems sense torque and increase aid as you increase effort. With PAS, there is no need to use the throttle, though some systems allow the throttle to work as an override when you want full power.
- Newton meter (defined in power-bike terms): A unit of torque in the SI Units (International System of Units, a complete metric system of units of measurement for scientists) system. Used to measure and rate the rotating force produced by a power-bike motor. The most important factor in determining how well a motor will climb hills and accelerate.
- Lithium-ion: The most commonly used power-bike battery type. Common lithium-ion chemistry used in power-bikes include lithium ion phosphate (LiFePO4) and lithium manganese oxide (LMO). Lithium-ion batteries are prized for their high-energy density, low self-discharge, and lack of “memory.”
- Watt: A unit of power in the SI system. Used to measure and rate the capacity of an e-bike motor to do work. A motor that is consuming more watts generally feels more powerful and usually reaches higher speeds.
- Watt hour (Wh): A measurement of electric charge. Watt hours rate a battery’s energy content. A watt hour is the amount of work required to produce one watt of power for one hour. When used to rate the capacity of e-bike batteries, watt hours are generally derived from the battery’s nominal voltage multiplied by its capacity in amp hours. This measurement is useful because it allows easy comparison of the energy content of several batteries, irrespective of voltage: a 36-volt, 10Ah battery would be labeled 360Wh; a 48-volt, 7.5Ah battery would also be labeled 360Wh.
- Volt: A unit of electric potential in the SI system. Production power-bikes generally run at 36 or 48 volts. In general, higher voltage means better electrical efficiency.
- Amp: An amp, or ampere, is a unit of current in the SI system. Amps measure the amount of charge flowing in an electrical system.
- Amp hour (Ah): A measurement of electric charge. An amp hour is the charge transported by a constant current of one ampere for one hour. A battery with a capacity of 10 amp hours can theoretically supply a constant current of one amp for 10 hours, two amps for five hours, and so on.
- Throttle: A handlebar control similar to that found on motorcycles or scooters, it is used to vary the speed of the motor. Power-bike throttles are usually twist-grip, thumb-lever or push-button types.
- Brushless: Conventional electric motors have a rotating armature wrapped with wound copper-wire coils. The armature and windings generally rotate inside a case with fixed magnets. These motors use brushes to conduct current between stationary wires and the rotating shaft. A brushless motor is constructed in reverse. The copper-wire coils are fixed and the magnets rotate. The brushless motor does not need brushes (no wear and no dust from the worn brushes to contaminate the engine), but it does require controller circuitry to operate.
- Hub motor: A motor that is incorporated into the hub of a wheel and drives it directly. The hub motor’s axle is held fixed in either the front or rear dropouts, and its shell is spun by internal electronics. Most modern electric bikes use hub motors.
- Direct-drive hub motor: The simplest type of hub motor. The magnets are fixed on the inside surface of the hub, and the windings are permanently attached to the axle. When power is applied, the hub is made to rotate around the axle. The advantages of a direct-drive hub motor include quiet (often silent) operation, few moving parts, and the ability to regenerate power into the battery (because the magnets are always moving over the coils). However, because the motor is always mechanically engaged, there is “cogging,” a drag that can be felt while coasting. Direct-drive motors must also be larger (and usually heavier) than comparable geared hub motors to achieve the same performance.
- Regenerative braking: Sometimes referred to as “regen,”direct-drive hub motors are capable of recovering a small amount of energy back into the battery while the bike is coasting. When active, the motor’s drag on the wheel increases markedly.
- Geared hub motor: These are hub motors built with internal planetary reduction gearing. In contrast to direct-drive motors, they can be smaller, more efficient and produce more torque. Geared hub motors are mechanically disengaged from the bicycle wheel when not powered, so they avoid the coasting drag experienced with direct-drive motors. These advantages come at a price; geared hub motors are more expensive, can be noisy (for electric, but still very quiet compared to any internal combustion system) and have moving parts that can wear out.
- Front drive: A front-drive bike has the hub motor in the front wheel. This is rarely used on production power-bikes, but is quite common for conversion kits.
- Rear drive: A rear-drive bike has the hub motor in the rear wheel. The vast majority of production power-bikes with hub motors are rear drive.
- Center drive: A center-drive bike mounts the motor or drive unit in the center part of the bike’s frame. The most modern center-drive units supply power to the bicycle chain, so the motor gains the advantage of any available gear options from the rear cassette and derailleur.
- Controller: The “brain” of an power-bike. Typically, the controller acts as a smart connection between the other components on the bike: motor, battery, throttle (if applicable) and the pedal assist.
- Pedelec: A chiefly European term meaning an power-bike with only a pedal-assist function and a speed limit of 25 km/h.
What are some of the benefits of Power Bikes
Powerbikes can be a useful part of cardiac rehabilitation programs, since health professionals will often recommend a stationary bike be used in the early stages of Rehab. Exercise-based cardiac rehabilitation programs can reduce deaths in people with coronary heart disease by around 27%; and a patient may feel safer progressing from stationary bikes to power bikes. They require less cardiac exertion for those who have experienced heart problems. Powerbikes can also provide a source of exercise for individuals who have trouble exercising for an extended time (due to injury or excessive weight, for example) as the bike can allow the rider to take short breaks from pedaling andalso provide confidence to the rider that they’ll be able to complete the selectedpath without becoming too fatigued.
Some individuals have even lost considerable amounts of weight by using a powerbike. By making the biking terrain less of an issue, people who wouldn’t otherwise consider biking can use the electric assistance when needed and otherwise pedal as they are able.
Power-bikes are zero-emission vehicles, as they emit no combustion by-products. However, the environmental effects of electricity generation and power distribution and of manufacturing and disposing of (limited life) high storage density batteries must be taken into account. Even with these issues considered, power bikes claim to have a significantly lower environmental impact than conventional automobiles, and are generally seen as environmentally desirable in an urban environment.
The environmental effects involved in recharging the batteries can of course be minimized. The small size of the battery pack on an power bike, relative to the larger pack used in an electric car, makes them very good candidates for charging via solar power or other renewable energy resources.
The environmental credentials of power bikes, and electric / human powered hybrids generally, have led some municipal authorities to use them.
Both land management regulators and mountain bike trail access advocates have argued for bans of electric bicycles on outdoor trails that are accessible to mountain bikes, citing potential safety hazards as well as the potential for electric bikes to damage trails. A study conducted by the International Mountain Bicycling Association, however, found that the physical impacts of low-powered pedal-assist electric mountain bikes may be similar to traditional mountain bikes.
A recent study on the environment impact of power bikes vs other forms of transportation found that power bikes are about:
· 18 times more energy efficient than an SUV
· 13 times more energy efficient than a sedan
· 6 times more energy efficient than rail transit
· and, of about equal impact to the environment as a conventional bicycle.
One major concern is disposal of used lead batteries, which can cause environmental contamination if not recycled.
There are strict shipping regulations for lithium-ion batteries, due to the safety issues. In this regard, lithium iron phosphate batteries are safer than lithium cobalt oxide batteries.
What is the difference between a Hub Drive & Mid Drive Motor
It’s a question that has been around since the dawn of power-bikes. You get an power bike for the first time and get addicted to the boost. Three weeks after riding you’re on the hunt for more power and looking at other motors.
Hub driven bikes are commonly powered by DC motors, typically brushless as they; perform better, are more reliable, and quieter (than brushed). If you want to know how a DC motor works or the difference between a brushed and brushless DC motor, Youtube can help you with that. Find one with animations as they help illustrate how they work with more details.
You’ll find a typical torque and power curve below for a DC motor.
With DC motors, torque is always maximum at zero speed which is called the stall torque. As you can see above, the motor’s torque will drop in a linear fashion with speed/rpm. The theoretical power curve will be a parabola shape and peak somewhere in the middle. Here’s a plot of the Fat-E Mini below.
With mid drives, they’re almost identical to hub motors however mounted at the bottom bracket of the bike. It directly connects to your cranks and gears. Because of this, you get a better power/torque curve. Imagine the hub drive dyno, but then add a plot for each gear like this:
Yeah a little crazy, but it’s pretty much the hub drive dyno for each gear. The curve stretches out with each higher gear. Do we remember what was said about power/torque plots? It’s the area underneath the curve that really shows the performance of a machine, especially when they’re rated at the same peak power/torque.
Let’s just assume that the peak power numbers for the Hunter are identical to that of the Fat-E Mini. Comparing the characteristics of each plot, you have the mini with one power curve whereas the hunter has multiple power curves (as many as the gears it’s fitted with). These multiple power curves are essentially combined which obviously would sum up to a large area – greater than a hub drive power plot (not always true, but typically). So in terms of performance, the mid drive is a clear winner.
How do they compare in handling?
As we should know by now the mid drive is installed on the bottom bracket with the battery/controller installed on the down tube. This keeps the bike’s center of the gravity very low and centered. With a hub drive, the center of gravity is generally a little higher than the mid drive by offset – either to the front or rear.
Depending on the wheel size, the hub motor could sit either higher or at the same height as a mid drive would. This results in the center of gravity being somewhat similar in terms of height, however the front or rear hub will shift the weight, either towards the front or rear. This will affect handling, and is especially the case with the front hub. Having a 3kg wheel that you turn with, will greatly impair the handling of a bike.
How does the mid drive stack up against the hub drive with price, maintenance and other things?
Frankly the mid drives trumps the hub drive in almost everything but price. They are more costly and when something does go wrong, they are more expensive to fix than hub motors. Another thing to consider is that hub motors are readily available with many options on the market. These motors are also easy to install and allow retrofitting. Mid drives on the other hand are a different story.
With many manufacturers producing complex high end mid drive motors, it makes it difficult, close to impossible to fit it to your current bike. Unless you’re a fabricator who can make a custom frame, it’s most unlikely for you to be able to buy a mid drive on a weekend and fit it on your daily commuter.