Faster SBU V3 Self Balancing Unicycle is ready to roll
By Paul Ridden
March 5, 2012
Inner city congestion, rising parking charges, pedestrian-only zones and other measures to persuade folks to leave the car at home can seem a little at odds with the increasing pace of our busy working lives. Getting the train to work is all well and good but if the office is quite a distance from the station, then workers are faced with hopping on more public transport or taking along a portable personal vehicle like a folding bicycle, mini scooter or unicycle. If you want to avoid having to hit the showers before sitting at your desk, then motorized versions of most are now available. Regular readers will already know that we're quite fond of the electric unicycle, particularly when it's combined with self-balancing mechanisms. One of the first to be featured was the SBU from Focus Designs, the third version of which has just been released.
Unlike pedal-powered unicycles, the SBU (self-balancing unicycle) doesn't take many, many hours of dedicated practice before users can confidently zoom past friends and family without looking like an arm-flapping, unstable idiot. The training time for the original was said to be around a couple of hours for the average user, but this was reduced further with the second version to about 20 minutes - although some folks might take to it in as little as five minutes. This short learning curve continues through to V3, with the option of attaching Noob Wheels (at US$85 for a set of two) under each of the foot wedges to help with balance.
There have been quite a few changes and improvements brought to the new model, beyond the funky new wheel design. The first is an increase of top speed at the expense of range. Focus Designs - the electronics designer behind the Solowheel - has gone for higher voltage 53V/2.5Ah Lithium iron phosphate (LiFePO4) battery packs for a range of at least 7.5 miles (12km), but the rider may be able to stretch that up to 10 miles (16 km). The SBU V3 manages a top speed of 15 mph (25 km/h) and zero to 10 mph (16 km/h) in three seconds from its 1000-Watt BLDC electric motor.
This is claimed to be enough for a sprint ride of about an hour or two hours around the city at a more leisurely pace. The multi-color LED status indicator in the center of the power button will keep you posted on the remaining charge and, when the juice does run out, the SBU won't just come to an abrupt halt and throw you off to the amusement of onlookers. It will gently slow the unit down while maintaining balance. There's a power override key lock, too, for the prevention of accidental activation during storage.
"For 95 percent of previous customers polled as well as a sampling of random people questioned this falls within an adequate range for both their commute and just plain zipping along town," the company's David Martschinske told us. "We've debated a bigger and longer range version but when it came down to it we needed to blend portability with range. It would be much more expensive and bulkier to effectively increase the range while still maintaining the performance boost of a higher-voltage battery. A lot of thought went into the decision of a higher voltage pack and users love the performance boost on SBU V3."
As before, the forward and backward axis self-balancing aspect is taken care of by onboard sensors with 1,000 balance calculations being made per second for rapid correction. Left and right leaning action is left to the user. A user leans forward to move, back to brake, left and right to turn. The SBU V3 also features some clever technology that will automatically slow down (Push Back) the vehicle if it detects that the rider is trying to push it beyond its capabilities.
Braking is undertaken by the hub motor, while regenerative braking technology also features, and there's variable speed control. Turn assist algorithms are said to provide stability throughout a turn, and the vehicle is able to climb a 30 percent grade hill.
Other obvious design changes can be seen in the new three-piece frame that's constructed from 6061 aluminum alloy with black semigloss powdercoating, and Version 3 is now shipped fully assembled instead of requiring partial assembly by the user.
"The look of the old frame was a little too boxy for us," said Martschinske. "We've completely gone back to the drawing board with the design and made this new SBU smaller and a lot sexier (at least in my option). We also removed the cheap looking stickers for labels and upgraded to laser marking."
"The old frame would get dinged up corners upon any crash," continued Martschinske. "This new frame is actually protected by the seat. In the event of any crash no part of the frame (except for the foot wedges) will hit the ground, resulting in a clean frame after any crash. The foot wedge would occasionally twist on impact and would require re-tightening quite often. It was rather annoying for customers (as well as us). The new foot wedge is much sturdier and designed to prevent any twisting. It is also capable of laying completely flat upon storage."
The design tweaks also result in Version 3 being a little lighter than the previous version at 27 pounds (12.2 kg), and the inclusion of a standard one-inch diameter seat post means that if you don't like, or are too short/too tall for the seat provided, you can slide in your own.
The SBU V3 is available now for US$1,795.
To help you judge whether the self-balancing unicycle is for you, have a look at the following promo video from Focus Designs.