When Bill Eggert takes his new invention out for a spin, it looks like an elliptical exercise machine that escaped from the health club and is rolling down the streets of St. Paul.
That’s what the 48-year-old inventor has essentially created: an elliptical trainer with wheels.
The St. Paul resident has had jobs ranging from bartender to data analyst, but he said he’s always been a bit of an inventor, coming up with schemes for a new way to produce ice or to generate electricity from the temperature changes between Minnesota winters and summers.
About four years ago, he started tinkering with an idea that started when he developed some running injuries.
“Tendons, knee stuff,” he said. A physical therapist suggested low-impact exercise like swimming or bicycling.
“I hadn’t been on a bike in 15 years,” he said. He went out for a 90-minute ride and didn’t feel like he got as much of a workout as he did from running.
“But my butt hurt from the seat,” he said. “My wrists hurt from the way I was holding the handlebars.”
He thought, “There’s got to be a better way to get exercise that’s outside, that uses a wheel.”
His goal was a weight-bearing but low-impact all-body workout. Just like an elliptical trainer.
“Would there be a way to get one of those things moving outside?” Eggert wondered.
The basic setup is a tricycle with a single drive wheel in the rear and two steering wheels in the front.
To propel the thing, the rider stands on the footpads connected to pivoting sliding shafts and makes elliptical stepping motions. You push and pull on arm levers at the same time. Both the footpads and the arm levers provide energy to a chain drive.
There’s an eight-speed internal geared Shimano Nexus hub. If you pedal backward, that will engage the coaster brake. You can also use a rim brake controlled by a hand lever.
The biggest challenge for the inventor was how to steer the machine while still exercising the arms. Eggert’s solution is a clever control linkage that allows you to turn the front wheels simply by twisting the hand levers.
Eggert has been tweaking variables like ground clearance, wheel size, wheel base and weight distribution to dial in the ideal performance characteristics.
Photo by Chris Denbow