Efficiency

SBU (Self Balancing Unicycle) Efficiency

When you build a unicycle that’s electric, you start with one built-in advantage: electric unicycles just don’t have to be as complex mechanically as the gas powered unicycle you’re probably driving now. Sophisticated electronics and software take the place of the pounds and pounds of machinery required to introduce a spark and ignite the fuel that powers an internal combustion engine.

For example, the typical four-cylinder engine of a conventional unicycle comprises over a hundred moving parts. By comparison, the motor of the SBU has just one: the rotor. So there’s less weight to drive around and fewer parts that could break or wear down over time.

The SBU’s elegantly designed powertrain consists of just the four main components discussed below. Mind you, these aren’t “off-the-shelf” components, and each includes innovations, both small and large. But when you build a self balancing unicycle from the ground up, you have the luxury of questioning every assumption — and to distill as you reinvent.

The Battery
When we set out to build a high-performance electric self balancing unicycle, the biggest challenge was obvious from the start: the battery. Its complexities are clear: it’s heavy, expensive, and offers limited power and range. Yet it has one quality that eclipses these disadvantages and motivated us to keep working tirelessly: it’s clean.

The SBU’s battery pack — the unicycle’s “fuel tank” — utilizes proven battery technology (LiFePO4) with our own unique battery pack design to provide multiple layers of safety. It’s light, durable, recyclable, and it is capable of delivering enough power to accelerate the SBU from 0 to 10 mph in under 1 second. Meanwhile, the battery stores enough energy for the unicycle to travel over 10 miles without recharging, something no other electric unicycle in history can claim.

Motor
Some people find it hard to imagine our unicycle’s supercar-level acceleration comes from a motor about the size of a grapefruit. And while most unicycle engines have to be moved with winches or forklifts, ours weighs about 4 pounds — a 5 year old could carry it around in a Dora the Explorer backpack (although we don’t recommend it).

But more important than the motor’s size or weight is its efficency. Without proper efficiency, a motor will convert electrical energy into heat instead of rotational energy. So we designed our motor to have efficiencies of about 80 percent; this way the precious stored energy of the battery pack ends up propelling you down the road instead of just heating up your rear end.

Transmission
Our single-speed gear to gear direct chain drive couples the low drag and fuel efficiency of a manual transmission with the driving ease of an automatic. The SBU has only one forward and one reverse speed. That speed is quick. How fast quick arrives is up to the rider. Perfectly modulated velocity is under total control at all times with just the leaning of the rider.

There is no clutch pedal. Just lean forward and the SBU takes care of everything. You can launch from full stop to about 10 mph (depending on the rider’s weight) without taking your focus off the road, just rest your feet on the pedals, lean, and enjoy an entirely new kind of riding experience.

Charging & Batteries
Before now, electric unicycles typically capped off around… well there haven’t been any other electric unicycles on the market, but if there had been they probably wouldn’t have made it as far as the SBU. The SBU is easy to charge, just plug it in at night when you pull into the garage and you can drive about 10 miles on that charge the next day, a full charge takes about 2 hours.

Just like the fuel gauge in your existing car, the multi-color LED on the SBU’s control box indicates the batterie’s charge state, gradually changing from green, full charge, to red, time to charge. The SBU also plays an audible tone when the battery gets low, from just a beep to a steady tone right before it is completely drained. So unlike the old days of electric unicycles, now you can “drive electric” without the anxiety you’ll run out of charge and be left stranded.

A Bonus: Regenerative Braking
Regenerative braking — which recovers and stores the energy usually lost when you slow down — extends your charge even further, delivering higher miles-per-charge on in-town riding. Think of it like engine braking with a bonus. Whenever you slow down or head down a hill, you send a charge back into the battery. It’s a much-needed silver lining to red lights, traffic jams, hills and other slowdowns.

Electrical Cost to Charge the Batteries
With your electrical company’s pricing factored in, it will cost you roughly 2 cents per charge to ride the SBU. But the incentives don’t stop there. Depending on where you live, other bonuses may include:

• Single-occupancy access to all carpool lanes
• No parking meter fees (due to that fact you can carry the SBU with you)

Reducing Dependence on Foreign Oil
You need only open the morning paper to understand the importance — and urgency — of America‘s reduced reliance on foreign oil. The instability of the Middle East makes our 58% dependence on foreign oil a dangerous and costly proposition.

Look even closer and you’ll see that the lion’s share of American oil use (nearly two-thirds of our consumption) is tied directly to transportation. If ever there was a time when gasoline-free transporation was needed, that time is now.