All-new XB4 1/10 off-road 4WD platform

Designed for highest performance at all levels of racing

New 2-in-1 concept allows use of either a short LiPo battery pack -or- saddle packs, and forward/rearward positioned motor

Engineered with attention to smallest details

Manufactured with legendary artistic craftsmanship from premium European materials

EFRA, ROAR, FEMCA spec compliant for stock and modified racing

Super easy to build, set up, maintain, and drive

Developed, designed and styled by Dipl. Eng. Juraj Hudy, manufactured exclusively by XRAY in Europe in the world's most sophisticated RC manufacturing facility

Revolutionary on-road platform with new benchmark for premium quality, reliability and performance

Premium XRAY service & support


Smarter chassis weight balancing options supports the 2-in-1 concept, allowing repositioning of battery packs, motor, electronics, and servo on different sides of the car

Unique XRAY Multi-FlexTM technology for easy chassis flex adjustment

Swiss 7075 T6 hardcoated 2.0mm aluminum chassis with countersunk holes for flush, smooth underside

Tough composite side guards perfectly fit the chassis to seal against dirt and protect from side impacts

Compact radio plate allows for mounting the receiver and speed controller for quick & easy removal and assembly; an antenna mount allows the electronics to be located in one place for easy servicing

Graphite front & rear upper decks for each of the 2-in-1 concept configurations, designed to work with different battery pack styles

New higher battery straps included to accommodate all possible battery configurations in the 2-in-1 concept (short battery pack -or- saddle packs)

New servo mounts allow the servo to be installed on either side (left or right)

Thicker 3.5mm graphite front shock tower & 3.0mm rear shock tower with multiple shock mounting and roll center positions

Reinforced front & rear bulkheads which allow access to the differentials using only 4 screws

All-new central bulkhead supports the 2-in-1 concept, allowing the slipper clutch to be oriented either frontwards or rearwards

Front & rear lower composite braces reinforce the chassis assembly with the desired flex

Differentials & Drivetrain:

Front & rear gear differentials with adjustable oil viscosity, featuring 35T crown steel gears and 14T steel pinion gears

Molded front & rear gear differentials for super-smooth, maintenance-free operation, features long-lifespan HUDY Spring Steel™ outdrives

All-new innovative aluminum motor mount allows left-or-right mounting to position the motor forwards or rearwards

Motor eccentric mounting plate inserts into an integrated motor holder/drivetrain support, allowing quick & easy motor rotation for gear mesh and secure clamping with a single screw

Robust central slip-adjustable clutch with 81T main spur gear molded from exclusive secret blend of composite material

Internal 1:2.5 drive ratio

All-new centric-design slipper clutch with ultra-efficient SLS material for more efficient & precise slip adjustment, and HUDY Spring Steel™ hardened outdrives for extra lifespan and reliability

Optionally-available central differential for use on clay and low-traction tracks

Constant velocity drives (CVD) are manufactured from special HUDY Spring Steel for reduced weight and increased durability. The shafts are hand ground for maximum precision

Two sets of CVD drive shafts for each of the 2-in-1 concept configurations

Reinforced safety collars for all CVD drive shafts to keep mounting pins securely in place

Ultra-lightweight 14mm wheel hex drive hubs CNC-machined from Swiss 7075 T6 and additionally black-coated have ultra-true hex clamping design which ensures solid mounting of the wheel

Optional 14mm offset wheel hex drive hubs available for super-fine track-width adjustment: -0.75mm, +0.75mm and 12mm: 0mm, -0.75mm, +0.75mm, 1.5mm, 2.25mm

Full set of 22 high-speed, blue-sealed ball-bearings used throughout the drivetrain to ensure maximum efficiency, degreased and oiled with Aero Shell® Fluid 12 for maximum smoothness and long life


Swiss 7075 T6 aluminum suspension holders front and rear

Integrated Suspension Settings (I.S.S.) for quick & easy suspension geometry setting using eccentric bushings inserted into aluminum suspension holders

Specially-designed suspension components manufactured from carefully formulated custom composite mixtures to ensure proper flex and durability

Race-perfected suspension geometry for superior performance and versatility in all racing conditions.

Lightweight 1-piece caster blocks with preset 9° caster with easy adjustable roll center position featuring larger openings for quick and easy disassembly of CVDs; optional 6° caster blocks available

Front chassis feature pre-angled caster of 8° and with the variable I.S.S. settings a range 16~20° of total caster can be achieved

Tiny yet robust steering blocks molded from a special composite mixture for maximum strength featuring adjustable lower roll center.

Very compact 0° toe-in rear uprights feature 2 different lower roll center positions + 3 different upper roll center positions, staggered inner/outer bearing sizes for improved load support and unsprung weight, and wheelbase adjustability via included shims

Oversized outer bearings to for increased dynamic loads

HUDY Spring SteelTM material for turnbuckles (featuring a tougher core) is used for front & rear upright linkages, steering system, and servo saver

Anti-roll bars manufactured from special spring steel material to stabilize the car at both front and rear are mounted to the diff cases & can be easily adjusted via linkages; laser-engraved markings for easy identification, available in different sizes for fine-tuning


Simple, effective dual-arm steering system with integrated adjustable servo saver ensures perfect steering and easy Ackermann and bump steer adjustment


Consistent, reliable membrane-free big-bore shocks with bleed-screw shock cap design feature up-stop shock rod travel adjustment (via O-rings) and downstop adjustment (via shims under pistons)

Swiss 7075 T6 aluminum shock bodies, lower nut & bleeder shock caps are hard coated in black

Super-precise molded Delrin™ pistons are offered with different holes & diameters for precise shock adjustment; for custom adjustment, a set of blank pistons (no holes) are also included

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

Premium shock springs designed specifically for big-bore shocks; manually measured, selected and matched into pairs to guarantee equal length and damping characteristics; laser engraved for easy identification

Full line of linear -or- progressive shock springs available

Premium silicone oils laboratory tested and calibrated to ensure highest possible consistency and quality

Bumper, Body, Wheels:

New composite rear wing holder was reinforced for better strength, reliability, and lifespan

Redesigned front lower bumper now protrudes from the bottom of the chassis to absorb all impacts from contact between the chassis and the track surface

Beefy 6mm thick body posts from special composite material for maximum strength

Newer more aggressive XB4 body is high-performance, low-profile, and aerodynamic to perfectly fit the new wider XB4 layout, with new profiles to increase stability and incorporated air channels for proper airflow

Specially designed 14mm hex hub wheels for high-competition racing; featuring reinforcement ribs to eliminate deformation and molded from very flexible material to retain shape even after impacts

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 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, roll centers, Multi-Flex™

Adjustable front & rear gear differential action (via oil viscosity)

Adjustable slipper clutch

Adjustable HUDY Sprint Steel™ turnbuckles (steering, front & rear upper links)

Multiple upper & lower shock mounting locations at front & rear

Adjustable Ackermann and bumpsteer

Adjustable front & rear anti-roll bars

Chassis pre-drilled holes for weight balance adjustment

XB4'15 Specs:

Class 1/10 electric 4WD off-road car
Width Adjustable 245-250mm
Length 352 mm
Wheelbase Adjustable 279-281 mm
Weight 850 g
Ready-to-run weight 1650 g
Chassis CNC-machined Swiss 7075 T6 aluminum2.0mm
Front upper deck Machined 2.0 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 9° 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 3.5 & 3.0 mm laminated carbon graphite (front & rear) with multiple shock mounting and camber link roll center positions
Type Full-time shaft-drive 4WD
Primary Pinion / spur
Drive shafts HUDY Spring Steel™ CVD drive shafts
Central shafts HUDY Spring Steel™ Direct Connection Shafts™
Differentials Sealed gear differential, 6 gear, silicone-filled
Slipper clutch Adjustable
Bearings Rubber-sealed high-speed bearings
Primary ratio: 12.5
Differential pinion 14T front / rear
Differential crown gear 35T front / rear
Spur gear 81T
Motor pinion Not included
Camber Adjustable front + rear
Front Caster 9° static +7~11° caster in chassis = 16°~20° total caster range
Optional 6° static +7~11° caster in chassis = 13°~17° total caster range
Toe-in Adjustable front + rear
Downstops Adjustable front + rear
Front kick-up Adjustable 7° ~ 11°
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 body wide
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 (48 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