THE QUADRILOGY Selectorized Leg Extension + Seated Leg Curl Machine (HOMEGYMCON 1 OF 2))

THE QUADRILOGY™ Leg Extension + Seated Leg Curl

THE QUADRILOGY is the fourth generation of our popular Leg Extension + Seated Leg Curl machine. It builds upon the feel, functionality, and adjustability of previous versions while incorporating higher felt resistance*, significant structural upgrades, premium materials, and numerous improvements developed from customer feedback.

The Quadrilogy is also one of the first selectorized Temple of Gainz machines available with our patent-pending Beyond Power VOLTRA Digital Resistance Integration. This optional configuration allows a compatible Beyond Power VOLTRA to replace the traditional weight stack, reducing the initial cost of the machine while providing greater control over resistance, eccentric loading, and resistance-curve customization^.

Estimated Shipping Timeline

Machines are currently in production, and orders are being accepted for production units.

Weight Stack Configuration: Machines equipped with a standard selectorized weight stack are estimated to begin shipping in mid-September 2026.

VOLTRA-Only Configuration: Machines equipped with the integrated VOLTRA mount and VOLTRA cable-routing components, without a weight stack or guide rods, are estimated to begin shipping in late September 2026.

All shipping dates are estimates and are subject to production, freight, and other delays. Please review our payment and cancellation policies, which apply to all purchased and unfulfilled orders.

What Is The Quadrilogy?

The Quadrilogy combines two highly effective lower-body isolation exercises, the leg extension and seated leg curl, into one heavy-duty machine with a compact footprint.

A fully adjustable back pad moves forward and backward to accommodate a wide range of users and body proportions. The extended seat pad and multiple back-pad positions provide additional support for taller users and those with longer legs.

The movement arm offers ten starting positions, while the leg roller includes five adjustment positions. The thigh pad provides eight secure starting positions for the seated leg curl. Together, these adjustments allow users to customize their starting position, range of motion, and alignment for both exercises.

Laser-engraved adjustment numbers on the movement arm, leg roller, and thigh pad make it easy to record and consistently repeat preferred settings.

The recessed front crossmember provides greater clearance and range of motion at the beginning of the leg extension and the end of the seated leg curl. The repositioned thigh pad and updated handle placement further improve comfort, stability, and ease of use.

What’s New for the Quadrilogy?

Structural Enhancements and Increased Rigidity

The Quadrilogy features extensive structural improvements designed to increase stability, rigidity, and long-term durability.

• Two additional crossmembers have been added to the lower and rear portions of the frame for increased structural reinforcement.
• Major frame connections have been upgraded to hex bolts secured with reinforcement plates.
• The thigh-pad and movement-arm mounting points have been heavily reinforced with welded triangular brackets, additional through-bolts, and reinforcement plates.
• The leg-roller assembly has been redesigned with additional triangular supports and reinforced bearing brackets on both sides of the movement arm.
• The leg-extension handles now use rounded mounting brackets designed to reduce play and movement while improving overall stability.

Larger Cam and Higher Felt Resistance*

The Quadrilogy frame and movement mechanics have been redesigned to accommodate a significantly larger cam. The larger cam increases the felt resistance during the leg-extension movement compared with previous versions.

The seated leg-curl pulley assembly has been engineered to create a mountain-peak-style resistance curve. Resistance begins at a moderate level, increases toward its highest point through the middle portion of the movement, and gradually tapers near the end range.*

The included 120 kg / 264 lb weight stack, combined with the machine’s updated cam geometry, provides substantial loading capacity for progressive overload across a wide range of users and training levels.

Premium Material Upgrades

Solid Guide Rods: The Weight Stack Configuration now includes upgraded solid-metal guide rods. These provide greater rigidity and allow the machine to be transported fully assembled when appropriate equipment, securing methods, and handling procedures are used.

Aluminum Pulleys Standard: Aluminum pulleys now come standard on all Quadrilogy configurations.

Knurled Aluminum Handles: Knurled aluminum handles replace the previous rubber-grip handles and come standard on both the leg-extension and seated leg-curl handle assemblies.

Updated Branding

The Quadrilogy introduces a new metallic Temple of Gainz shield logo, a redesigned and streamlined exercise instruction label, and new Temple of Gainz purple-themed weight-stack decals.

The exercise instruction label is optional. The purple portions of the weight-stack decals may also be trimmed away by the customer to create a black-and-white appearance, if preferred. Any decal modification is performed at the customer’s discretion.

Configuration Options

The Weight Stack Configuration includes a 120 kg / 264 lb selectorized weight stack, solid-metal guide rods, the standard weight-stack cable, aluminum pulleys, and knurled aluminum handles.

The VOLTRA-Only Configuration includes the integrated VOLTRA mounting system, VOLTRA-compatible cable routing, a direct 1:1 attachment option, and a hook attachment point for an optional 1:2 pulley configuration.

The VOLTRA-Only Configuration does not include a Beyond Power VOLTRA, DIY Dock, weight stack, guide rods, climbing pulley, or the standard weight-stack cable. A compatible climbing pulley is required for 1:2 operation and must be purchased separately.

Compact Footprint

Despite its versatility, adjustability, and heavy-duty construction, the Quadrilogy delivers heavy-duty functionality within a manageable footprint suitable for home gyms, personal-training studios, and light commercial facilities.

Please review the dimensions shown in the product gallery, including the machine’s minimum and maximum dimensions across its available adjustment positions.

*Felt Resistance Disclaimer

Published pulley ratios, weight-stack values, and resistance descriptions are provided for general reference and do not guarantee the exact force experienced by every user. Actual felt resistance may vary based on cam geometry, cable routing, pulley configuration, machine settings, seat and pad positions, user height and limb length, exercise technique, range of motion, movement speed, cable tension, friction, maintenance condition, manufacturing tolerances, and any digital resistance settings used.

The nominal 1:1 pulley ratio describes the cable-routing relationship and should not be interpreted as a guarantee that the force experienced at the leg roller will exactly match the selected weight throughout the entire movement. Resistance changes through the range of motion based on the cam profile, movement-arm position, and user setup. Comparisons with other machines, free weights, cable systems, digital resistance devices, or prior Temple of Gainz models are inherently approximate.

^Beyond Power VOLTRA Compatibility, and Safety Disclaimer

The Beyond Power VOLTRA and DIY Dock are manufactured and sold separately and are not included.

Users must follow all operating instructions, warnings, resistance limits, setup requirements, and safety guidance provided by both Temple of Gainz and Beyond Power.

For additional information regarding VOLTRA use and digital resistance integration, please review our Digital Resistance Integration Disclaimer before purchasing or using the machine.

By purchasing the VOLTRA-Only Configuration or using a VOLTRA with the Quadrilogy, the purchaser acknowledges that they have reviewed and accepted the Digital Resistance Integration Disclaimer and understand the applicable operating instructions, resistance limitations, safety guidelines, inherent risks, and user responsibilities.

Future Weight Stack Conversion

Customers who purchase the VOLTRA-Only Configuration may later purchase the components required to convert the machine to the traditional Weight Stack Configuration, subject to availability and compatibility.

The current estimated price for the conversion package is $649, plus applicable taxes and freight shipping. Freight shipping may cost approximately $400 or more, depending on destination, carrier rates, delivery requirements, and accessorial charges.

Pricing and availability are subject to change. Installation is not included.

Delivery and Assembly Expectations

Please review our Shipping Policy and Product and Assembly Disclaimer before purchasing, including all delivery, inspection, installation, and assembly expectations.

By completing a purchase, the customer acknowledges and agrees to the applicable shipping, assembly, payment, cancellation, safety, and product-use policies.