Revolutionary & unique chassis design

First 1/10 off-road 2WD chassis with Multi-Flex Technology™

CNC-machined Swiss 7075 T6 alu backbone provides stability and stiffness, allowing torsional flex

Precision-engineered composite chassis plate absorbs vibration and works with Multi-Flex Technology™ to allow independent front and rear flex adjustment

Top deck comprised of graphite top deck and alu front brace connected via bushing

Front, center, and rear drivetrain bulkheads keyed to composite frame

Super-easy and fast diff access

Lengthwise & lateral reinforcing braces

Integrated 25° front pre-angle

Well-designed layout for optimum weight distribution and balance for carpet and astro surface

Smart & innovative motor mount with eccentric mounting plate gives solid mounting, and allows for quick & easy mesh adjustment

Composite battery straps

CNC-machined shock towers made from premium-grade 3.0mm thick graphite material, includes variable shock mounting positions

Optional weight mounting positions

Beefy 6mm thick body posts


ISS™ suspension holders for quick & easy suspension geometry setting

Complete set of CNC-machined Swiss 7075 T6 alu eccentric bushings included

Suspension arms made from exclusive composite mixtures, perfect balance of reliability and performance

CNC-machined SFA™ graphite stiffeners for quick & easy flex adjustment (optional)

Wheelbase adjustment for frontward/rearward weight balance adjustment, or wheelbase shortening/lengthening

Caster blocks made from lightweight & robust composite mixture have preset 6° caster angle

Tiny & tough steering blocks molded from special composite mixture for maximum strength

Compact, strong rear uprights with multiple upper & lower roll center mounting position

Anti-roll bars made of special spring steel, interchangeable between front & rear


Shaft-driven 2WD drivetrain with 1:2.5 internal ratio

Adjustable central slipper clutch made with HUDY Spring Steel™ and ultra-efficient SLS material, gives quick & easy tuning of power delivery from motor to drivetrain

CVDs made from world-renown HUDY Spring Steel™ have the world’s thinnest but most durable drive shafts used in electric off-road cars

CVD assembly features composite safety collars to ensure a captured mounting pin

Drive shafts are hardened by a proprietary process, providing unbeatable lifespan and reliability

Precision-molded, lightweight, robust 81T spur gears

Lightweight 14mm wheel hex drive hubs CNC-machined from Swiss 7075 T6 black-coated alu

Full set of 18 high-speed, blue-sealed ball-bearings, degreased and oiled with Aero Shell® Fluid 12


Super-smooth, super-light maintenance-free composite gear differential is ideal in most types of tracks

Adjustable gear differential stiffness via oil viscosity

Super-lightweight diff outdrives made from HUDY Spring Steel™ are hardened for extended lifespan and reliability

Optional externally-adjustable ball differential for low-traction tracks


Dual-arm steering system is simple yet effective

Integrated easily-adjustable servo saver

Quick & easy Ackermann and bumpsteer adjustment


Big-bore, membrane-less shock absorbers for easy, consistent building and rebound setting

Up-stop and down-stop travel adjustment

CNC-machined shock body, lower nut and bleed shock caps made from Swiss 7075 T6 alu for maximum strength, hardcoated for extra durability

Super-precise Delrin™ molded shock pistons

Shock rods machined from special steel material, precision hand-ground for maximum smooth operation, and additionally hardened for increased lifespan

SLP aluminum shocks have been shortened by more than 7mm to provide maximum stability under all track conditions, while reducing traction roll under high-traction conditions

Specially-designed shock springs compliment new big bore shocks; available in linear or progressive

Shock springs are manually selected for maximum precision, equal length, and equal damping characteristics, laser-engraved for easy identification

Premium silicone shock oils created specially for XRAY use industry-standard cSt ratings

Body, Wing & Wheels

DMX high-performance, low-profile aerodynamic body specially designed by XRAY for perfect fitment and optimal downforce, made from premium-quality Lexan® material

Stylish, effective rear wing made from strong Lexan® material perfectly complements new DMX body

Specially-designed XB4 wheels are perfect for high-performance racing, featuring aerodynamic shape and special reinforcing ribs

Assembly, Set-up & Support

Premium 3D full-color Instruction Manual & supplementary sheets

To fully understand the set-up possibilities we recommend the legendary HUDY Set-up Book (available for download exclusively at which is loaded with over 50 pages of high-quality pictures and easy-to-read RC car set-up explanations

Exclusive Virtual Online Setup Sheet database with thousands of set-up sheets for race tracks around the world

Premium, unmatched XRAY online support

Adjustment Possibilities:

Fully-adjustable front and rear suspension geometry: caster, camber, toe, kick-up, anti-squat, ride height, downstops, track-width, roll center, wheelbase

Multi-Flex Technology™

ISS™ holders and machined inserts

SFA™ graphite plates for suspension arm flex adjustment

Adjustable gear differential stiffness via oil viscosity

Roll center upper & lower adjustment, front and rear

Adjustable HUDY aluminum turnbuckles (steering, front & rear upper links)

Multiple upper and lower shock mounting locations at front and rear

Adjustable Ackermann and bump steer

Adjustable front and rear anti-roll bars

Chassis pre-drilled holes for weight balance adjustment

XB4 2WD Specs:

Class: 1/10 electric 2WD off-road car
Width: Adjustable 245-250mm
Length: 362mm
Wheelbase: Adjustable 284-290mm
Weight: 800g
Ready-to-run weight: 1615g
Chassis: CNC-machined Swiss 7075 T6 aluminum
Chassis tray: Composite 1-piece
Front upper deck: Machined 2.1 mm laminated carbon graphite
Suspension: Adjustable suspension via Integrated Suspension System I.S.S.
Rear suspension: Lower arm with adjustable upper camber link
Front suspension: Lower arm with adjustable upper camber link and with 6° caster blocks
Rear upright: Composite 0° toe-in with dual arm mounting and 3 roll center positions
Shocks: Big bore membrane free shock absorbers with Delrin pistons
Shock towers: Machined 3.0 mm laminated carbon graphite (front + rear) with multiple shock mounting and camber link roll center positions
Type: 2WD
Primary: Pinion / spur
Drive shafts: HUDY Spring Steel™ CVD drive shafts
Central shafts: HUDY Spring Steel™ Direct Connection Shaft™
Differentials: Sealed gear differential, 6 gear, silicone-filled
Slipper clutch: Adjustable
Bearings: Rubber-sealed high-speed bearings
Primary ratio: 1:2.5
Differential pinion: 14T front
Differential crown gear: 35T front
Spur gear: 81T (84T option)
Motor pinion: Not included
Camber: Adjustable front + rear
Front Caster: 6° static +23°~27° caster in chassis = 29°~33° total caster range
Toe-in: Adjustable front + rear
Downstops: Adjustable front + rear
Front kick-up: Adjustable 23°~27°
Rear anti-squat: Adjustable 1° ~ 5°
Anti-roll bars: 1.2mm front / rear
Ackermann: Adjustable
Bump steer: Adjustable
Steering: Centrally-positioned dual steering system
Body, Tires, Wheels & Misc
Body: XRAY XB4 DMX body
Tires: Not included
Wheels: XRAY Aerodisk 14mm Wheel hex hub
Adjustment Possibilities Standard adjustment: Camber, toe-in, caster, track width, wheelbase, kick-up, anti-squat, roll center, Ackermann, bump steer
Instructions: Full-color manual with 3D graphics (40 pages)
Set-up book: Not included. HUDY 2-color off-road set-up book (40 pages) can be downloaded in the „Download section“ and it shows 1/8 off-road models in photographs contained within it. However, the methodology and set-up theory are the same for all modern 1/10 off-road cars.
Packaging: Carton box with vinyl bags with parts
Additionally included: HUDY Graphite Grease, Silicone Oils, Authentication Certificate, Set-up sheet, Parts list & Exploded view, Decals
Items Not Included
Radio system (transmitter and receiver), steering servo, motor, pinion gear, LiPo battery packs, speed controller, charger, tires, inserts, double-sided tape, CA glue, bearing oil, medium-grade (blue) threadlock, universal tool for all nuts and turnbuckles and other tools

All specifications are subject to change without prior notice. Pre-production prototype is shown, final specifications may slightly vary. In some pictures optional parts may be shown. All option parts are not included and must be purchased separately. The color of some aluminum parts may vary from kit to kit and some of the kits may not include all the orange or black parts as shown. Some of the spare parts or option parts may not be available at the moment in the orange or black color as shown.