Frog Legs is the world-wide expert in wheelchair suspension. with over 14 years experience we manufacture the original and best wheelchair shock absorbing caster forks available. Attention to even the smallest detail has resulted in the lightest, strongest, most functional high-resilient urethane caster wheels developed specifically for wheelchairs.

About Mark Chelgren

Mark Chelgren completed his education in Astro- and Geo-Physics at the University of California in Riverside. Chelgren worked through college as a Manager and Auditor for Forbco Management in Anaheim, Ca. and then as a Geo-Physist for GeoSoils in Temecula.

In 1994 Chelgren befriended members of a quadriplegic rugby team. Having a technology progressive, crank head bicycle mentality, he began asking what was really missing from the ultimate wheelchair ride. The answer was undoubtedly that Wheelchair riders were tired of being jostled and bounced around from pretty minor bumps. Everyday life is not smooth. Chelgren's studies conducted in partnership with Iowa State University prove that 80% of the vibration that enters a wheelchair comes from the front caster forks and wheels. Primary ailments caused by the rough ride of traditional caster systems are muscle spasms, lower back pain and skin shear to name just a few. Frog Legs eliminate 76% of all vibration in a wheelchair. The forks also provide improved mobility and stability that prevent the rider from being pitched out of their chair onto the pavement. The decision was made - focus on the front wheels.

Mark met his wife on RAGBRAI in 1995. Janet Beisch was a native Ottumwa girl, graduate of IHCC living in Cedar Rapids working as a computer consultant.

In 1996 Chelgren re-located to Iowa and worked with Janet to publish and circulate a business plan for Frog Legs. In 1997 Chelgren received a patent for his suspension caster forks and began production from a facility in Vinton, IA. 

1999-2001 Recognized by Govenor Tom Vilsack in his official State of the State address, Chelgren is asked to co-chair an economic development committee.

2006 Chelgren relocated Frog Legs to Ottumwa and purchased a facility at 14470 Terminal Avenue. After years of experience, countless hours of consulting with clients, and attention to even the smallest detail, Chelgren’s Frog Legs are renowned for manufacturing the lightest, strongest, most effective wheelchair suspension systems and wheels in the world.

2007-2008 Chelgren appliee for patient of metallic and polyurethane area-spring / force-dampening material. The patent covers eleven applications including military, construction, and shipping arenas. Initial partnership / lease-of-technology agreement with South Carolina based corporation, Safe Ports, who specializes in International Security and Shipping has been completed. Safe Ports has begun work to complete ballistics testing and will then initiate marketing strategy focused on military and shipping relationships.