S&M ATF XL Frame (20" Wheels)

Product Overview

The S&M ATF XL is an extended-geometry version of the ATF frame engineered for riders 6'1" and taller. Features a 5" integrated head tube, 9" standover height, and top tube options up to 22" for proper fit on taller riders. Built with butted Thermal-X chromoly tubing and 4Q-Baked dropouts for durability across street, park, and dirt applications.

Key Features

• Extended XL geometry – 5" integrated head tube and 9" standover provide adequate clearance and reach for riders over 6'1" without the handling compromises of upsized standard frames
• Four top tube options – 21", 21.25", 21.5", and 22" lengths allow precise cockpit sizing based on torso length and arm reach preferences
• Butted Thermal-X tubeset – Variable-thickness chromoly tubing removes material from low-stress zones while reinforcing critical areas to reduce weight without sacrificing impact resistance
• Integrated seat clamp – Built-in clamp eliminates external hardware for cleaner aesthetics and removes a common failure point from overtightened traditional clamps
• 4Q-Baked dropouts – Heat-treated 14mm slot dropouts increase material hardness to prevent flex, cracking, and thread wear under high torque loads
• Mid BB height (11.7") – Balanced bottom bracket position provides stability without excessive pedal strike risk during grinds or low-clearance obstacles
• Thread-on 990 brake mounts – Removable U-brake bosses maintain clean frame lines when running brakeless, sold separately for riders who need braking capability

Technical Specifications

• Top Tube Lengths: 21", 21.25", 21.5", 22"
• Rear End Length: 13.4"
• Head Tube Angle: 75°
• Head Tube Style: Integrated (45°/45°, 41.8mm internal diameter)
• Seat Tube Angle: 71°
• Seat Clamp: Integrated
• Seat Post Size: 1" (25.4mm)
• Bottom Bracket Height: 11.7"
• Bottom Bracket Style: Mid
• Standover Height: 9"
• Brake Mounts: Thread-on 990 (mounts sold separately)
• Dropouts: 14mm slot, 4Q-Baked
• Gyro Tabs: None
• Weight: 4.75 lb (2.15 kg)
• Tubeset: Butted Thermal-X chromoly tubing

Compatibility and Ideal Use Cases

This frame is designed for standard 20" BMX wheels, not cruiser class. Requires forks with integrated race systems (45°/45° angular contact bearings with 41.8mm crown race diameter). The integrated seat clamp accepts 1" (25.4mm) diameter seat posts only—verify compatibility with your existing post. 14mm slot dropouts work with 14mm bolt-on axles or 3/8" axles using adapter sleeves. Thread-on 990 brake mounts must be purchased separately if you run brakes. No gyro tabs means this frame supports brakeless or direct-cable brake setups only. Best suited for riders 6'1" and taller who need extended reach and standover clearance for technical street riding, park sessions, and transitions. The 13.4" rear end length and 75° head tube angle provide responsive steering while maintaining stability at speed.