Photo credit: Stealth Bikes   

1.  Fast Electric Bikes are expensive to buy

The technology is now here to make a fast electric bike. There has never been a better time. Lithium battery technologies have greatly improved in the last 5 years that make spectacular results achievable.

The best option if you want to own an electric bike that is fast, is to build it yourself. There is only one established manufacturer (see our article on the  pictured Stealth Bomber) that is offering a turn key fast bike (50mph) and it is indeed expensive ($12,000). If you build the bike yourself you can make a  similiarly fast bike for $3000 but it probably won’t be nearly as safe, reliable and clean looking as the Stealth. Depending on your building skills your bike might turn out to be downright dangerous and ugly.

Why does a fast bike cost so much money?  Componentry (controller,  and motor)  that will withstand high speeds is expensive. And mostly Good lithium batteries capable of high energy discharge are expensive, and to go this fast for any length of time you need a lot of quality lithium (the bigger battery the higher the discharge it can withstand).

Read how an ebike can actually save you money.

2.  Fast Electric Bikes are illegal

Why are not more manufacturers making fast electric bikes for the public? An electric bike that goes over 20mph is suppose to have a license plate to be operated on the roads in the USA. Oh yeah and don’t forget turn signals, horn, mirrors which would just ruin the idea of a bike.

It is possible your fast electric bike can get you in trouble with the law, especially if you ride recklessly.

If it can be proven that you electric bike goes over 20mph, depending on your jurisdiction, it could be considered by the law as being an unlicensed motor vehicle.

As long as an electric bike goes under 20mph it is classified as a bicycle, and penalties for traffic infractions are much smaller than on a full fledged motor vehicle.

Read our Story on 2013: Year of the fast production Ebike

Read our story on USA Ebike Law

Liveforphysics on the fastest electric bike on the planet 80mph

3.  Fast Electric Bikes are inefficient

Once you go over 30mph on an electric bike, the power it takes to push the bike through the wind  becomes substantial.  Electric bikes are much more efficient at 20-30mph range than they will be at the 30-50 range.  Although it is true you will be using a lot more electricity than you would if you are going slower, the price of the electricity to run even a  large electric bike is pennies per charge. But if you want to go fast, to hold all this extra energy, you will need a much heavier battery. Lugging a heavy battery around sucks as all electric bike riders know, but it is the price you have to pay for high speed.

Usually you could pedal assist your electric bike to provide some human power to make your e-bike go farther on the same battery.  However pedaling  on a fast electric  bike can be a frustrating experience.  The bike above puts out over 100,000 watts. Imagine if the rider (liveforphysics) was pedaling he would get maybe an extra 100 watts of power. Most riders of high power bikes do not bother with pedaling unless the battery dies. Which happens quickly at high speeds.

There is one electric bike builder, Cedric Lynch, who tried to address the issues of efficiency loss at high speed due to wind resistance and came up with this electric bike design which could go at speeds as high as 60mph very efficiently….with his high power set up he did not bother with pedals:

Cedric Lynch in his “Feet First Streamliner”

4.  Fast Electric Bikes are heavy

The bike above (Death Bike) is probably the fastest electric bike in the universe (do not let its “super slow bicycle” decal fool you). It also pays the price with its weight,  at over 200 pounds. The motor, battery and controller on this e-bike are  enormous.

Some slimy e-bike manufacturers claim ridiculous top speeds on petite looking ebikes.  If you want an e-bike to go fast you need to bulk up the bike.

As an example of what is necessary to go fast, the Stealth Bomber mentioned earlier weighs in at 120 pound.  The Stealth Bomber needs 1500 watt hours of battery in order to get a reasonable  range at high speed. The Bomber is a bear to pedal if the battery dies. Stealth Bikes is a reputable company with a quality product and they do not exaggerate performance numbers.

Fast electric bikes because of their big battery and big motor are heavy. For a 50mph bike, expect your bike to weigh at least 100 pounds with todays motor and battery technologies.

5. Fast electric bikes are bulky and not pretty

The bike above has a drive train built by “Thud”  and is on our list of 10 fastest bikes. As you can see it is not pretty or petite.  When e-bikes are built to go fast they usually do not look very slick although there are a few (very expensive) exceptions. (check out our elegant garage built bike list for some examples) Fast E-bikes generally pay the price of looking ugly to achieve their high speeds.

Take a look at the huge bikes in our Top 10 Utilitarian  Ebike List

            Photo credit: Zombiess   

6. Fast electric bikes are not stealthy

A high performance motor and battery is hard to hide. Even when a builder takes the time to hide unsightly wiring, and make his bike look clean he still will have enormous electrical components hanging out.

Another factor with fast electric bikes is they usually make a lot of  motor and chain noise (especially mid drives), so not only do you not look like a regular bike, they also dont sound like one. If your goal is to fit right in with the other bicycle riders,  you should not aspire to own a fast electric bike. Also if you ride too fast (over 25mph) it will also be a dead give away.

The bike pictured above uses a hub motor (Cromotor) and is therefore relatively quiet.  However would you be fooled into thinking this is a regular pedal bike if you saw it parked outside your neighborhood donut shop?

7. Fast electric bikes are unreliable

Once you start riding an electric bike at speeds of over 30mph you have become a test rider. As long as you have used a lot of common sense on the construction of your frame, forks,  tires and wheels you should be safe. However more than likely you can count on your fast set up being somewhat unreliable.  The bike above (built and pushed by Thud)  is set up with RC components which are lightweight, powerful, efficient, and slick looking but not very reliable. The pusher seen above fried two motors, and roasted one battery pack in less than 3 miles of racing. An expensive day at the track.

If you ride a fast built yourself e-bike, plan on break downs as part of the equation. And fast electric bikes because of their weight etc. are not easy to pedal when they do break down. Pushing your heavy ebike home being passed by pedal bikes is not a glamorous duty.

            Photo credit: Kingfish   

8. Fast electric bikes are expensive to upkeep

As parts break on your fast electric bike  your cost of ownership will add up. Nowhere is this more seen on than on lithium batteries. The faster you discharge a lithium battery, the shorter its life span will be. The cost of replacement of a large racing lithium battery pack is expensive.

Pictured is Kingfish who rode his fast electric bike 1500 miles from Seattle to California in a 2 week  trip. Pictures is the batteries he used for that trip. Each of those packs cost around $50. By the next summer time, 8 of those battery packs had gone bad. Although nothing beats the performance and density of lipo batteries, if not well constructed with a good bms, they usually do not last very long in a high performance application.

9. Fast electric bikes can be dangerous

The pictured electric bike broke its front fork in its first race and sent the rider/builder tumbling over the handlebars and onto the pavement. Luckily he was not hurt. In fact serious injuries have so far been rare in the United States. However the danger always exists when going fast on 2 wheels, and electric bikes are no exception. Especially when fast bikes are built without quality components. Remember most bicycle components although inexpensive were designed for low speed.

Another example of wheel failure comes on liveforphysics 80 mph bike while joy riding the day after the race. At high speed the wheel came unlaced. Luckily the rider was not hurt:

Photo credit: Liveforphysics

10.  Fast electric bikes are risky for the e-bike movement

In New York city e-bikes are illegal. The fine for riding an electric bike in NYC is $5000. The reason for the clamp down is bicycle messengers riding hot rodded electric bikes at high speeds freaked out the citizens. (read our story on NYC illegal Ebikes) . This is an example of what can happen if fast  e-bike riders are not responsible and ride recklessly.  A few bad apples could potentially spoil the entire barrel.

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