The BodyKore GR639 Leg Curl / Extension is a commercial selectorized strength machine that pairs two complementary lower-body movements in one station. The leg extension isolates the quadriceps through a guided knee-extension arc, while the leg curl targets the hamstrings as the knee flexes, giving balanced front-and-back thigh development from a single piece of equipment. Its dual-function design is ideal for facilities that want complete leg training without dedicating floor space to two separate machines, and it suits beginners, general members and advanced lifters alike.

A 220 lb selectorized weight stack powers the GR639, adjusting with a single pin so users can switch between curls and extensions or change loads in seconds. The sealed guide-rod system provides the smooth, consistent resistance expected on a high-traffic commercial floor, with a quiet, predictable feel rep after rep. As athletes get stronger, the stack upgrades to 340 lb, letting one machine keep pace with progressing members and protecting the facility’s investment over the long term.

Built on a rolled steel oval-tube frame finished in black or silver, the GR639 is engineered for durability under daily commercial use. The movement arm tracks on hardened guide rods for a stable, repeatable path through both the curl and extension, and adjustable thigh and ankle pads position the knee joint correctly so resistance lines up with the working muscles. The result is a biomechanically sound platform that maintains tension through a full range of motion and helps users train hamstrings and quads with clean, controlled form.

Measuring 68" x 50" x 65" and weighing 582 lb, the GR639 occupies roughly 24 square feet, giving it a planted, stable feel without crowding the strength area. It is backed by a lifetime frame warranty per BodyKore, reflecting its heavy-duty build. The dual-function GR639 is well suited to commercial gyms, hotel and multifamily fitness centers, physical-therapy clinics and serious home gyms that want both hamstring and quad isolation from one durable, light-commercial machine.

Specifications

Downloads

• BodyKore GR639 Leg Curl / Extension Spec Sheet (PDF)