WHAT'S THE BASIS FOR THE "70% EASIER TO CONTROL" CLAIM?
Basic physics! Wind hitting the canopy from the side causes the umbrella to rotate in your hand. The torque created at your hand is equal to the wind force (F) on the canopy times the distance (D) between the canopy and the grip location; T=FxD. By reducing the distance between grip position and canopy, the torque is reduced. Since you have to counter the wind-generated torque to keep the umbrella in position, it's better to hold the umbrella closer to the canopy. But holding the skinny shaft introduces another problem: grip ergonomics.
A "power grip" requires a grip diameter of 1¼ to 2 inches. Grabbing the skinny shaft (½ inch diameter) results in a "precision grip", with a grip strength that is ~75% weaker than a power grip. While holding the shaft in calm conditions doesn't create a lot of strain (since you're not required to counter wind forces, just the weight of the umbrella), holding the shaft in windy conditions quickly creates stress in fingers & hand as you squeeze to maintain control and push against the wind to keep the umbrella in position. In the 20mph wind case from above, the torque on the hand could be up to 40 lbs at the handle and 20lbs at mid shaft!
As a side note, grip ergonomics is the reason most hand tools that require application of force (e.g., hammer, paint roller, broom, rake) have a grip diameter of 1¼ - 2 inches. And imagine trying to lift weights at the gym with a ½ inch diameter bar!
Using a power grip located closer to the canopy provides much more comfortable, reliable and sustainable control. And it enables you to respond more quickly to swirling winds and sudden gusts. The combination of grip size and location is the key to staying dry.
So the elegant GRIP2 design addresses human factors by placing the right-sized grip in the right location for comfortable and reliable control with one hand (in most wind conditions; a two-handed grip is recommended in extreme wind conditions).
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