S&M Big Jumper 26" BMX Frame

The Big Jumper is S&M's 26" wheeled dirt jump frame designed for suspension forks and disc brakes. Features integrated chain tensioners, tapered headtube for modern forks, and geometry optimized for 100-120mm travel suspension. Built with increased tire clearance, engraved headtube, and T-slot seat tube for improved quick-release clamp compatibility. Made in the USA and available in four top tube lengths from 22" to 23.5".

Key Features

• Tapered headtube compatibility – Accepts 1.5" tapered steerer tubes (42mm upper/52mm lower in 45×45 style) for modern suspension forks with increased front-end stiffness
• Integrated chain tensioners in dropouts – Built-in adjusters eliminate need for separate tensioner hardware and allow precise chain tension adjustment for single-speed setups
• Disc brake mount with adapter system – Post-mount disc tab accepts 160mm rotors with included 20mm IS-to-post adapter, or 140mm rotors with 0mm adapter
• Four top tube options – Available in 22", 22.5", 23", and 23.5" lengths to accommodate different rider heights and cockpit preferences
• T-slot seat tube design – Improved seat tube slot profile provides better clamping surface for quick-release seatpost clamps compared to traditional round slots
• Increased tire clearance – Accommodates 26" x 2.25" tires when slammed or 2.35" tires when pulled back slightly in dropout slots
• Engraved headtube graphics – Permanent branding on headtube won't wear off like decals

Technical Specifications

• Top tube lengths: 22", 22.5", 23", 23.5"
• Rear end (chainstay) length: 15.1" (slammed)
• Head tube angle: 69°
• Seat tube angle: 73°
• Bottom bracket height: 12.6" (0.400" drop from axle centerline)
• Standover height: 10"
• Head tube: 120mm tall, integrated 42mm/52mm (1.5" tapered), 45×45 style
• Bottom bracket: 73mm Euro BB
• Dropouts: 3/8" slots, 135mm spacing with integrated tensioners
• Brake mounts: 160mm disc with 20mm IS-to-post adapter (140mm with 0mm adapter)
• Seatpost size: 27.2mm
• Seat clamp size: 30mm
• Maximum tire: 26" x 2.25" (slammed), 2.35" (pulled back)
• Maximum sprocket: 30T (standard chainline), 32T (with additional spacers)
• Frame weight: 6.15 lbs (22" top tube)

Compatibility and Ideal Use Cases

Designed for 100-120mm travel suspension forks or equivalent rigid forks with 1.5" tapered steerer tubes and integrated headsets. Requires 73mm Euro bottom bracket, 27.2mm seatpost, and 135mm rear hub spacing with 3/8" axle. The disc brake mount works with hydraulic or mechanical disc systems using post-mount calipers and 140-160mm rotors. Best suited for dirt jumping, pump tracks, and transition riding where 26" wheels provide better rollover, bump absorption, and braking compared to 20" BMX bikes. The longer wheelbase and slacker 69° head angle prioritize stability at speed and on landings over quick steering response. The 22"-23.5" top tube range accommodates riders approximately 5'8" to 6'2" tall, though individual fit preference varies based on riding style.