Chase RSP 5.0 OS20 Frame Dirt

Product Overview

The Chase RSP 5.0 OS20 in dirt is a premium aluminum BMX racing frame built on race-proven geometry refined through feedback from pro riders Connor Fields and Joris Daudet. Constructed from 7005-T6 ultralight aluminum with hydroformed and muscle-formed tubing, it features tapered headtube, internal cable routing, disc-brake-only design, and oversized OS20 geometry for larger riders. The frame represents the culmination of iterative upgrades to Chase's iconic RSP platform, delivering responsive handling and structural rigidity for competitive racing.

Key Features

• 7005-T6 premium ultralight aluminum – Aerospace-grade aluminum alloy provides superior strength-to-weight ratio with reduced weight compared to standard 6061-T6 frames
• Double-butted hydroformed top tube – Variable wall thickness in the top tube reduces weight while reinforcing the seat tube junction for improved rigidity and responsive feel
• Triple-butted hydroformed down tube – Three-stage wall thickness optimization maximizes strength at stress concentration points while minimizing material elsewhere for optimal stiffness
• Muscle-formed rear stays – Advanced forming process creates optimized tube profiles that improve rear-end stiffness and acceleration response during hard racing
• Internal cable routing – Brake housing routes internally from headtube through down tube, bottom bracket, and exits chain stay (Expert XL and larger) for clean aesthetics and protected routing
• Tapered integrated headtube (1-1/8" to 1.5") – Modern tapered geometry on Expert XL and larger sizes provides a stiffer headtube interface and improved steering precision
• Integrated 1-1/8" headtube (Mini, Junior, Expert) – Standard headtube design on smaller frame sizes for universal sealed headset compatibility and broad parts availability
• Disc-brake-only design – Dropouts restructured specifically for disc brake compatibility with improved clearance for various brake calibers and rotor sizes
• Post and flat-mount compatible – Works with both postmount and flatmount disc brake adapter systems for flexible brake setup choices (adapter sold separately)
• CNC-machined closed dropouts – Precision-cut 3/8" (10mm) closed dropouts with integrated tensioners keep the rear wheel locked in position without movement
• Integrated chain tensioners – Built-in tensioners eliminate the need for separate tensioner devices on most frame configurations
• Press-fit bottom bracket (Expert XL and above) – Press-fit 86mm BB provides a lighter, stiffer bottom bracket interface compared to traditional threaded systems
• Euro BSA bottom bracket (Mini, Junior, Expert) – Traditional 68mm threaded bottom bracket on smaller frame sizes for broad component compatibility
• OS20 geometry – Oversized wheel format (20" wheels with larger diameter) optimized for taller, heavier riders seeking improved comfort, stability, and rolling characteristics
• Dirt colorway – Earthy brown finish with professional graphics and durable paint application
• Race-proven pedigree – Geometry refined through professional race feedback and proven at the highest levels of BMX racing competition

Technical Specifications

• Material: 7005-T6 premium ultralight aluminum alloy
• Color: Dirt (earthy brown)
• Wheel size: OS20 (20" wheels with oversized rim diameter)
• Headtube design: Integrated tapered 1-1/8" to 1.5" (Expert XL and larger)
• Bottom bracket: Press-fit 86mm (Expert XL and larger)
• Rear axle: 3/8" (10mm) bolt-in, closed dropouts with integrated tensioners
• Brake system: Disc brake only (postmount and flatmount compatible with adapter)
• Tubing construction: Double-butted, triple-butted, hydroformed, and muscle-formed
• Internal cable routing: Yes, from headtube through frame to chain stay exit (Expert XL and larger)
• Aero seat post tube: Yes
• Available frame sizes (20"): Mini, Junior, Expert, Expert XL, Pro, Pro+, Pro XL, Pro XL+, Pro XXL, Pro XXL+, Pro XXXL, OS Pro XXL, OS Pro XXXL
• Available frame sizes (24"): Cruiser Pro, Cruiser Pro+
• Included components: Chain tensioner and bolts, housing damper foam
• Not included: Aero seat post, aero seat post clamp, disc brake adapter, brake housing

Compatibility & Ideal Use Cases

The Chase RSP 5.0 OS20 frame in dirt is designed for BMX racers using OS20 wheels, forks, and tires—primarily larger and heavier riders seeking improved comfort and rolling characteristics while maintaining competitive racing geometry. It requires an OS20-compatible fork for proper geometry and tire clearance. The frame is disc-brake-only and requires a separate disc brake adapter (postmount or flatmount, sold separately). Compatible with standard 3/8" (10mm) BMX rear hubs and sealed bearing headsets. Select Expert XL or larger sizes for tapered headtube and press-fit bottom bracket performance; Mini, Junior, and Expert sizes feature integrated 1-1/8" headtubes and traditional 68mm bottom brackets. Not compatible with rim brake systems, non-OS20 forks, or traditional threaded bottom bracket cranks on Expert XL and larger sizes.

DOWNLOAD RSP 5.0 FRAME BRAKE SETUP NOTICE

Please note: Brake fluid on paint that is not silicone-based can act like a paint thinner and eat away at the coating of your paint, causing it to peel. Due to different types of paints/decals/materials used for BMX parts, do not let the Brake Fluid touch any part of the bike, as there can be significant self infliced damage due to this.

Integrated Tapered Head Tube
For stiffer tapered steer tube fork

NEW Integrated Cable Routing
Routed from head tube to chain stays

NEW Restructured Enclosed Dropouts
To offer better clearance for a wide array of disc braking with internal built-in tensioners

Aero System shape
To improved aerodynamics and a slightly stiffer feel.

Press Fit Integrated BB86 Bottom Bracket
Simple and easy way to install

Born from some of the best alloys for building BMX race bikes, our special 7005-T6 SpeedLite alloy is the perfect blend for our Hydroforming process, giving the RSP frames the core strength needed to produce unmatched speed on the track, while keeping the overall weight of the frame down to a minimum.

Chase utilizes the triple butting on our line of RSP 5.0 frames. A triple-butted tube means it has three different wall thicknesses along its length. Chase uses this technology to reduce the amount of material used when building the RSP 5.0 frame, decreasing its weight by 15% compared to last years frame tubes used to construct the frame. Lighter where it can be and stiffer where it needs to be means no excess weight on the bike that gives you an advantage with the RSP 5.0 frame and against the completion.

Chase utilizes tapered tubing to offer you the most durable, yet light weight products, to help you achieve optimum results on the BMX race track. Our tapered items, use multiple thicknesses in the same tube, so the tube can be reinforced where needed with precision to help reduce stress areas where needed and lighten up the areas that don’t require extra materials. In aluminum the result are tube walls that eliminate stress points, boosting strength, reducing weight and improving fatigue life. The advantage is clear : Tapered tubes enhances strength and durability, at less weight.

Hydroformed tubes have two main advantages. First, the narrow axis is a flatter surface, which means more surface area to carry the load, so it is stiffer & stronger across the minor axis. Secondly, the deeper axis is stiffer since the stiffness varies to the cube of the diameter, stronger to the square. When using an oval shaped tube on a typical BMX frame it helps reduce flex but only in one direction, but on the Chase frames, the tubes are oval in both directions in the main flex areas and these tubes help reduce flex in both main directions.

Chase RSP 5.0 Frames feature the Aero seat post tube, seat post, and seat post clamp into BMX racing. This is to not only to help gain fractions of a second on the track with improved aerodynamics, but the Aero tubes also offers a slightly stiffer feel. We know BMX bikes don’t need to go fully aero testing into a wind tunnel, but when races are won or lost by fractions of a second, every advantage will help.

All Chase Frames feature Muscle Forming for Chain and Seat Stays, a technique to give the back end of the ACT & RSP frames the stiffness and design shape we wanted and needed for optional design a special mold and process were needed to let us build the ultimate frame. Used with Carbon Fiber or Alloy to do just that, while letting us design the exact shape, design, and thickness to offer the optional designed back end on the Chase frames.

For the Chase RSP 5.0 frames, we have restructured the dropouts to offer better clearance for a wide array of disc brake calibers, improving the overall braking performance. Like the RSP 4.0, we have designed them to be able to take the extra force created by using a disc brake and disc brake mount, now compatible for both post mount & flat mount disc brake system.

While each rider is unique, Chase has developed Bio Fit sizing for our frames to offer riders the ultimate size options for BMX racing. The sizing used for the Chase line has been carefully designed to give riders the optimum power output in the size range offered. Our commitment to details and offering many size options, gives you a custom fit BMX frame, that you can buy right at your local Chase BMX Dealer..

Chase RSP 5.0 Frames use a Integrated Tapered Headtube. Tapered head tubes offer a combination for the bearing sizes. Our tapered head tubes have a 1-1/8” upper diameter to 1.5” lower diameter. this allows you to run a tapered steer tube fork, or use a full 1-1/8” fork steer tube, with the offered 1.5” lower bearing, when the headset has an optional 1-1/8” to 1.5” fork race option.

Chase RSP 5.0 Frames use a Press Fit style Bottom Bracket tube. Press Fit BB are a simple and easy way to install a Bottom Bracket, where the Bottom Bracket you supply for your frame has the Bearings in cups and simply press into the frame, eliminating the chance of damaging BB threads, with the traditional Euro BB. The BB is usually lighter and easier to install and remove as well.

Chase RSP 5.0 Frames feature an Fully enclosed, Extra long (2.3″ or 60mm) axle area slot, 10mm drop outs. The Enclosed system also houses an Internal system with built-in alloy tensioner, allowing you to use the full length of the dropout.

Chase RSP 5.0 Frames feature new Internal Cable Routing from the Head Tube, through the Down Tube & Bottom Bracket, and exits out of the Chain Stay (exits out of the bottom of the down tube for small sizes), giving you the factory look, as well as providing protection for the brake cable and graphics, since the cable does not rub against the frame.

GEOMETRIES :

NOTE: RSP 5.0 frame weights listed are weighed exactly how the frames arrives to you, with paint, decals, & clear coating.