PHOTOS: KEN FREUND
SUMOSPRINGS ‘AIRLESS AIR BAGS’ TAKE THE RATTLE AND ROLL OUT OF YOUR RIDE
by KEN FREUND
B ang, clang, shake, rattle and roll! If your motorhome has a jarring ride or sounds like a barrel full of bolts when it’s going down the road, read on. We recent- ly installed SumoSprings, an interesting concept dubbed the “world’s first airless air bags.” De- signed to reduce banging and rocking, smooth out the ride and provide additional load support, SumoSprings basically take the place of air bags and mount on sim- ilar brackets. However, they don’t require any air lines, compressors, gauges or maintenance. In fact, the company’s motto is “fit it and forget it.”
SumoSprings are cylindrically shaped suspension aids made from dense micro-cellular polyurethane, with exclusive additives that provide a graduated spring-rate curve. They’re manufactured in a high-tech proprietary multistage hot-casting process, producing a unique closed-cell micro-cellular urethane. This results in progressive compression under load; they become firmer the more you compress them, which
helps eliminate harsh bottoming out. According to the manufacturer (SuperSprings International Inc.), they are compressible by up to 70 percent of their orig- inal height, making them ideal for high-dynamic load- ing compared with the typical 20 percent compression for material used by other manufacturers. They’re also extendable to 30 percent of their unloaded height with full memory rebound, which lets them act as a shock absorber on the upstroke too.
SuperSprings engineers designed and tested SumoSprings for excellent abrasion resistance, and the company says the product is highly resilient to oils, salts and UV rays. The ribbed profile provides minimal transverse expansion, so unlike an air-inflated bag that expands laterally when compressed, SumoSprings compress without bulging when under load. That allows them to work in confined spaces where air bags might rub other suspension parts.
SumoSprings are significantly larger than a larger bump stop and act as variable-rate springs
MOTORHOME l September 2010