Q: Where can I buy one?
A: The BOWGO (patented) is not yet commercially available, but we are negotiating licenses to manufacture and market this as a product. If you want to be informed when the BOWGO is available, just send us email at bowgo@cs.cmu.edu and please let us know how you heard of BOWGO and this website.

Q: What does this have to do with robotics?
A: The idea for the bow spring arose from efforts to develop a highly efficient and resilient leg for hopping and running robots. The leg has worked well in small hopping robots (a few pounds in mass), but we wanted to determine what problems would occur if we scaled the technology to a much larger scale. The performance of the BOWGO confirms that hopping and running robots on the scale of 200 pounds are feasible and will be able to operate efficiently.

Q: What makes the BOWGO superior to conventional pogo sticks?
A: First, the FRC spring allows much greater energy storage (2-5 times) for its weight than a steel coil spring. Second, the bow-shaped spring precludes the sliding friction inherent in long coil springs due to lateral buckling. Third, guide rollers minimize plunger sliding friction.

Q: How high can one bounce on the BOWGO?
A: The BOWGO easily clears the ground by 10-20 inches. Our present height record is 48 inches. For comparison, you should take a look at Pogomatic, a powered pogo stick developed at UC Berkeley.

Q: Can I put one spring on each foot and do two-footed hopping and running?
A: Yes, this is certainly possible. The feeling of hopping on a single, large spring is quite different from the feeling of running with a smaller spring under each foot. In fact there is a product that attaches to each foot, called Powerskip that is available for about $1,000. You should also look at the Kenguru Boots as well as Bionic Boots which are also described here in an article.

Q: On what surfaces can the BOWGO be used?
A: The large, rubber foot is suitable for dirt and firm, grassy surfaces. With a special foot, we have hopped on sand and gravel. We have even considered a snow-shoe! We avoid concrete and other hard surfaces because of safety concerns, and stay clear of obstacles that could cause injury.

Q: Is the BOWGO difficult to ride?
A: The skill needed for moderate hopping on the BOWGO is comparable to that needed for a conventional pogo stick. Higher hopping requires more practice and greater concentration to maintain body attitude during the long flight phases.

Q: For what size riders is the BOWGO suitable?
A: The current prototypes are designed for riders weighing about 150 pounds, and have been used successfully by riders weighing 120-200 pounds. A heavy rider is more apt to "bottom" the plunger, while a light rider may find the spring too "harsh." The BOWGO design can be tailored to particular rider size and weight, just as commercial pogo sticks are sized for various weight ranges.

Q: Is riding the BOWGO good exercise?
A: Subjectively speaking, we find that 20-30 minutes with the BOWGO provides an entertaining and invigorating workout for the whole body. Like skiing or skate-boarding, the BOWGO introduces and element of control that challenges balance skill and involves whole-body motion. We have noted improved strength and endurance in bicycling after training with the BowGo. There is evidence that the repeated, sustained periods of acceleration and free-fall provide general strengthening of the body tissues.

Q: What are the limits of performance for the BOWGO?
A: BOWGO performance may be limited by energy or control. The spring must be able to store elastic energy equivalent to the potential energy at the height of the bounce, and the rider must be able to produce the force necessary to store that energy in the spring. The rider must also put in energy each hop to make up for losses due to friction, spring hysteresis, ground-contact and impact losses, etc. For long flight times, the rider must minimize the rotational motion (pitch and roll) at take-off to maintain an upright posture for landing.