Ethos also addresses residual vibration via ISO TECH, a patent-pending technology that acts as a second shield for the rider. “There are towers that extend out from the base frame that connect to the seat frame, and inside those towers are polymers,” Rettler said. “They are available in different densities or durometers. No matter what density you use, you always get the vibration-damping benefits of the chair design through the seat frame isolation, and then these secondary shields, the polymers. They absorb any of the residual vibrations that traveled through from the base frame up through the towers.”
K0005 Performance Requirements
While reducing everyday vibration is significant, Ethos must also fulfill other K0005 requirements, such as a high level of adjustability, plus an ultralight weight that facilitates propulsion and transporting the chair.
“I didn’t want to lose any energy going to the wheels or efficiency in pushing,” Ludovici explained. “There are other ways to dampen vibration. You can have soft casters on the front; you can have soft wheels on the rear. But that slows you down. You use a lot of energy, and you don’t roll as far. With the Ethos, you’re able to use performance tires front and rear and get the efficiency of the pushing, but the way the seat frame is somewhat separated from the base frame with the elastomers, the seat then becomes part of your body. It’s the difference between riding on top of something and being [part] of something.”
Rettler said Ethos’s design also provides optimal weight distribution: “The benefit of integrating the caster into the base frame and not attaching it to the seat frame is now you have this ability to manage the wheelbase. That caster telescopes in and out of that base frame, so you get about 4″ of adjustability of that front caster. No other rigid frame does that.
“The result is that you can optimize the placement of the wheel, you can optimize the chair setup for performance or for more stability, but you’re not sacrificing one for the other anymore. You can also balance the weight of that rider across the wheelbase in such a way that no other chair allows you to do.”
Ludovici agreed: “You can get a fairly aggressive center of gravity and still be able to push the casters way forward for stability. I’ve always had a pretty on-the-edge center of gravity, but if I lean forward to pick something up, I want the front of my chair stable. I get as long a wheel base as I can squeeze into a chair without making it extra long. You can pick up stability that way, and it doesn’t really hurt your performance.”
Experienced K0005 users won’t need to change their routines to use Ethos. “For transfers, because the casters aren’t tied to the front frame, it gets rid of that bar or tube that’s usually there,” Ludovici said. “You can get closer to things when you transfer. As far as pulling it in and out of the car, the crossbrace is placed in pretty close to a medium balance point, so if you pick it up by the cross tube, it’s not heavy one way or the other.
“People say that monotube frames are the easiest and the most compact, but it’s not really true because you’ve got a bunch of parts sticking out from underneath that monotube. If you pull it across your chest to put it in a car, you’ll usually bump yourself. With the Ethos, there are three different heights of the bottom frame to try to keep the distance between the seat and the bottom of the frame relatively minimal.”
Ethos is available in seat widths from 12″ to 20″ and seat depths from 14″ to 20″, with a 275-lb. weight capacity. Its transport weight is 11.6 lbs., and seat-to-floor heights are 13.5-20.5″ (front) and 13-20″ (rear). Choose the best polymer to further dial in the ride; Ki provides the ISO TECH guide to help.
“Alan doesn’t like to sense any compression on the front end of the chair, so he rides a very dense polymer,” Rettler said. “For someone that might go into spasms when they ride over a rough surface, a really soft polymer might be preferred to help minimize spasticity.”
Ethos challenges conventional wisdom: It’s an ultralightweight, highly adjustable chair that can also reduce the vibrations that users feel. No loss, all gain.
“It doesn’t sacrifice weight,” Rettler said. “The chair responds the way a full-custom dual-tube does. The ride is incredible. Then to have this opportunity to tailor the ride experience and have adjustability that no other chair gives you? Through changes in abilities, injury, sensitivity, age, etc., Ethos can adapt. The ability to optimize the ride without a sacrifice to weight or performance while also providing the vibration damping benefits for a more comfortable ride? It’s a beautiful thing.”