Gronk Fitness Selectorized Dual Ab / Back

The Gronk Fitness Selectorized Dual Ab / Back is a selectorized core strength machine designed for abdominal crunches, back extensions, trunk flexion, trunk extension, and guided core stabilization training. This dual-function ab and back machine helps users strengthen the abdominal muscles, lower back, spinal erectors, and core support muscles in commercial gyms, school weight rooms, personal training studios, and serious home gym environments.

Built with a solid steel frame, selectorized single-stack resistance, self-lubricated bushings, high-grade pulleys and cables, an aluminum weight stack pin, ergonomic seat and backrest, and marine-grade double-stitched upholstery, it provides smooth movement and fast resistance changes for multiple users. The compact dual-purpose design allows facilities to train both anterior and posterior core strength from one professional strength station.

Key Features

• Dual-function abdominal and back extension machine for complete core training
• Selectorized single-stack resistance system allows quick weight adjustments
• Designed to target the abdominal muscles, lower back, spinal erectors, and core stabilizers
• Solid steel frame supports demanding residential and commercial strength environments
• Self-lubricated bushings help create smooth and consistent exercise motion
• High-grade pulleys and cables support reliable selectorized resistance performance
• Aluminum weight stack pin allows fast resistance selection between users and sets
• Adjustable seat and backrest help users find a more secure training position
• Ergonomic seat and backrest improve comfort during abdominal and back extension movements
• Marine-grade double-stitched upholstery adds durability for repeated facility use
• Compact 51.2" L x 37.4" W footprint fits efficiently into strength training layouts
• Final-stock Gronk Fitness selectorized machine for buyers seeking remaining available inventory

Feature Highlights

• Dual Ab And Back Training: This machine combines abdominal flexion and back extension into one selectorized station, helping users train both sides of the core without requiring separate machines for abs and lower-back work.
• Selectorized Single-Stack Resistance: The adjustable weight stack allows users to change resistance quickly with a selector pin, making the machine practical for personal training, circuit training, school weight rooms, and commercial gym floors.
• Smooth Pulley And Bushing System: High-grade pulleys, cables, and self-lubricated bushings help provide consistent resistance through the movement path, allowing users to focus on controlled core contraction and proper form.
• Adjustable User Positioning: The adjustable seat and backrest help accommodate different body sizes and exercise setups, which is important for facilities serving a wide range of members, athletes, and training clients.
• Commercial-Ready Comfort: Marine-grade double-stitched upholstery, an ergonomic seat, and supportive backrest padding improve comfort while helping the machine withstand repeated use in higher-traffic training spaces.

Exercises

The Gronk Fitness Selectorized Dual Ab / Back v2 supports abdominal crunches, trunk flexion, back extensions, trunk extension work, core stability training, high-repetition abdominal sessions, lower-back strengthening, and machine-based core circuits. Users can adjust the selectorized resistance to match their strength level, training goal, and desired movement difficulty.

Who This Is For

This machine is ideal for users who want guided abdominal and lower-back strength training from one compact selectorized station. It is well suited for commercial gyms, school and athletic weight rooms, personal training studios, apartment fitness centers, rehabilitation-oriented fitness spaces, and serious home gyms that need durable core training equipment.

Specifications

• Product Type: Selectorized Dual Ab / Back Machine
• Brand: Gronk Fitness
• SKU: 5408-G2
• Category: Core Strength Machine
• Primary Exercises: Abdominal Crunches and Back Extensions
• Target Muscle Groups: Abdominals, Lower Back, Spinal Erectors, and Core Stabilizers
• Resistance System: Selectorized Single Stack
• Length: 130 cm / 51.2 inches
• Width: 95 cm / 37.4 inches
• Height: 146 cm / 57.5 inches
• Product Weight: 106 kg / 233.7 lbs
• Load Capacity: 80 kg / 176.4 lbs
• Frame Material: Solid Steel
• Pulley System: High-Grade Pulleys and Cables
• Bushing System: Self-Lubricated Bushings
• Weight Stack Pin: Aluminum Weight Stack Pin
• Seat: Ergonomic Adjustable Seat
• Backrest: Ergonomic Adjustable Backrest
• Adjustability: Adjustable Seat and Backrest
• Upholstery: Marine-Grade Double-Stitched Upholstery
• Assembly: Assembly Required
• Status: Final Stock
• Application: Residential and Commercial Strength Training

Warranty

Important Warranty Notice: Warranty coverage applies according to the full Gronk Fitness warranty policy, including all terms, conditions, exclusions, proof-of-purchase requirements, and use-environment definitions.

• Residential Coverage: Lifetime frame, 2-year upholstery, lifetime parts, lifetime attachments, 3-month cosmetic, and 1-year labor.
• Commercial Coverage: 10-year frame, 1-year upholstery, 5-year parts, 1-year attachments, 3-month cosmetic, and 1-year labor.

Resources

• Gronk Fitness Dual Ab / Back Assembly Manual
• Gronk Fitness Warranty Information
• Sell Sheet