Engineered and manufactured in-house at the XRAY factory located in Slovakia, Europe, the XB4 is a fantastic demonstration of XRAY’s attention to detail in all of its products. The XB4 is created by XRAY’s design staff using premium European materials and sophisticated German and Swiss machines.

XRAY’s Ty Tessmann achieved the first ROAR National Championship for the XB4. Tested and successfully run in the highest competition races now you can enjoy the winning platform.

XRAY XB4 has been one of the most successful 4WD off-road cars in the EOS racing series, winning 4 overall season titles. In 2019 it was again Bruno Coelho winning the season title in one of the most competitive races in the world.

The XB4’20 chassis was lengthened to increase stability, while maintaining the desired the chassis flex for the best balance of traction and steering. The chassis was also narrowed in the front and rear sections to create the clearance necessary for the new suspension holders and narrower geometry.

The chassis accommodates the lower motor mount and allows the motor to be placed lower in the chassis that improves the cornering speed and stability.

CNC-machined from high-quality Swiss 2mm 7075 T6 aluminum, the chassis is strategically machined in low-stress areas to make it as light as possible without affecting strength or rigidity; and it is additionally black-coated for increased lifespan.

The all-new super-strong narrow bulkheads provide the needed clearance for the new narrow suspension holders on the XB4’20. This additional clearance allows for a wider range of track width adjustments and for moving the inner suspension pivot closer to the vehicle centerline. The new bulkheads have a perfect fit to the all-new front and rear differentials and are reinforced to increase their reliability.

The XB4 bulkheads allow super-fast & easy diff exchange and servicing by dismounting only 4 screws from the front of the bulkhead and bottom of the chassis. This super-fast diff access is available at both front & rear. The bulkheads have minimal ball-bearing play, resulting in increased gear teeth lifespan and minimized gear stripping. 

All-new graphite plate is used for the rear bulkhead height adjustment. Increasing height of the gear box makes the car more reactive in the high traction conditions and is suggested for use on carpet tracks.

For the low traction conditions, it is suggested to remove the graphite plate to place the bulkhead lower and thus generate more traction. Suggested for dirt tracks.

The all-new gear differential was completely redesigned both in front and rear, featuring a split design of the cover and crown gear. The differential case also has greater internal oil volume to increase consistency of the diff action, yet it is significantly narrower to fit into the new narrower bulkheads and to move the rotating weight closer to the centerline.

The super-smooth, low maintenance gear diff includes a composite case and cover with internal satellite gears that are precision-molded from special XRAY-developed graphite composite material, ensuring a long lifespan and super-smooth, efficient operation.

Gear differential features all-new diff-outdrives designed for use with 2.5mm pin.

The all-new split design of the gear differential features a separate lightweight crown gear and a separate diff cover. The split design results in significantly lower rotating mass and improves the serviceability.

The crown gear is now CNC-machined from HUDY Spring Steel and is ultra-hardened making it very strong and reliable with a longer life span. The split crown gear allows for a simpler exchange to optional gears without requiring a rebuild of the internal diff assembly.

To improve the gear engagement both crown gear and pinion gear have more teeth and new geometry that results in smoother engagement and increased efficiency.

The all-new shorter slipper clutch reduces rotating mass and improves efficiency. The new slipper components shorten the entire central assembly to reduce weight yet still provide a greater adjustment range for both low and high traction conditions. Both outdrives are shorter and are also updated for the 2.5mm driveshaft pins now used throughout the XB4’20 drivetrain.

The adjustable 3-pad slipper clutch ensures smoother clutch operation and more efficient braking, and clutch adjustment is easier, more consistent, and ultra-fine. The lightweight slipper clutch plates have a machined relief which decreases the friction surface to assist with clutch slip adjustment.

The slipper clutch pads are made from ultra-efficient SLS material with very high slip efficiency. The clutch outdrives are super lightweight, manufactured from HUDY Spring Steel™ and additionally hardened for extra lifespan & reliability. The slipper plates are machined from premium Swiss 7075 T6 and additionally hardened, then given a black final surface treatment.

The optional central differential was also completely redesigned. Using the same universal diff case and internal parts found in the new front/rear differentials, the central diff has greater internal oil volume to increase consistency of the diff action, yet at the same time it is significantly shorter than the previous version to fit the new narrower central assembly and to minimize rotating mass.

The maintenance-free super-smooth gear diff includes a composite case and cover with internal satellite gears that are precision-molded from special XRAY-developed graphite composite material, ensuring a long lifespan and super-smooth, efficient operation.

Gear differential features all-new diff-outdrives designed for use with 2.5mm pin. The gear diff set includes 81T spur gear and 78 and 84T spur gears are available as an option.

The central differential is recommended for use on clay, bumpy Astro and low-traction tracks to increase traction.

 

 

Available as option only #364904

The diff outdrives were redesigned with a smaller design for the new front and rear differentials and the new narrower slipper clutch assembly. The center outdrives now feature the same 2.5mm pins used on the front and rear diffs.

To reduce rotating weight, the super-lightweight diff outdrives are machined from HUDY Spring Steel™ material which allows additional material to be removed on the outer part of the outdrives, further reducing the weight without effecting durability. The inner part of the outdrives is additionally hand-ground for perfect fitment into the diff case.

The outdrives are hardened using XRAY’s own special hardening process to provide extended lifespan and reliability.

Everything is new on the central driveline – drive shafts, motor mount, slipper clutch, drive gears, bevel gears. Everything is new, lighter and more compact for improved efficiency and reliability.

The front and rear driveshaft lengths are updated to match the new differential width and suspension geometry; the front drive shaft is 83mm long and the rear drive shaft is 75mm long.

The safety collar on the front driveshaft secures the pin, while the ball bearing captures the pin in rear axles, both preventing the pin from coming lose during a run.

XB4 constant velocity drive shafts are manufactured from world-renowned HUDY Spring Steel™ and feature 2.5mm drive pins for maximum drivetrain efficiency. The drive shafts are some of the world‘s thinnest yet most durable drive shafts used in electric off-road cars. Hardened with a proprietary hardening process, the drive shafts provide unbeatable lifespan and reliability.

The motor mounting plate features a new shape for easier access to the pinion gear set screw. The inner motor screw is now recessed into the mount for improved clearance around the center spur gear.

The motor is connected to an eccentric mounting plate, with the assembly then inserted into an integrated motor holder/drivetrain support. The design allows quick & easy motor rotation to adjust gear mesh, and still securely holds the motor plate using only a single screw.

To ensure the motor will not loosen in a serious crash or due to insufficient tightening, the motor plate has a bayonet mounting system which prevents it from being dislodged from the motor holder. By rotating the motor mount plate to the opposite direction, the motor can be quickly removed from the vehicle.

Removing the motor or adjusting the gear mesh is easy and fast, with changes possible in only a few seconds.

The central assembly features a new upper top deck to match new layout of the motor mount and central bulkheads on the chassis plate. The entire assembly is more compact with weight placed as close to the chassis centerline as possible. The new upper deck also fits the optional central differential’s new case design and dimensions.

The graphite central upper deck holds ball-bearings in the motor mount and bulkhead assembly, while the upper deck allows easy access for slipper clutch adjustment.

The XB4’20 includes the updated roll center mounts for the rear uprights.

The upper roll center is adjusted at the camber linkage via shims (up/down & in/out), while the lower roll center is adjustable via eccentric inserts for 9 different positions (up/down & in/out).

The multi-function uprights have the upper roll center position in the middle of the axis of the driveshaft joint to help generate more traction and increase stability.

There are three different uprights available: hard (included), graphite (optional), and aluminum (optional), each suitable for particular track conditions.

The rear shock tower has a new design so it can be mounted in front or behind the rear bulkhead. The rearwards assembly put more weight on the rear with more downforce to the rear as well generating more rear traction, suggested for low traction tracks.

The optional rear aluminum shock tower features new three different wing mounting positions for improved adjustability.

Both front & rear shock towers are machined from premium-grade graphite and are lightweight & strong, with multiple shock positions and roll center adjustment positions.

All-new narrower suspension holders move the inner pivot location closer to the vehicle center allowing to use longer and shorter suspension arm alternatives and new suspension geometry. The narrower design increases rear traction.

The aluminum suspension holders feature Integrated Suspension Settings (I.S.S.™) which allows for quick & easy suspension geometry set-up.

Machined from premium Swiss 7075 T6 aluminum and black coated.

The reinforced servo saver stands are now machined from one piece to simplify assembly and to improve steering precision, especially in high traction conditions.

The dual arm steering system is very simple yet effective and features an easily adjustable, integrated servo saver. Ackermann is easily adjusted by quickly changing the steering link mounting positions on the steering plate.

Bump steer is adjusted for more aggression by inserting a shim between the steering block and steering linkage.

The servo mount has a more compact and stronger design. The servo mount is now secured to the side guard to eliminate any unwanted servo movement that can occur in very high traction conditions. The reduced deflection translates into more consistent and precise steering response while cornering. 

XRAY Instruction Manuals have become the industry standard, being simply the best manuals you will ever get with an RC model car. Whether you are a first-time builder or an experienced racer, all the instructions are straight-forward and easy to understand. The full-color instruction manual contains large 3D illustrations that show all assembly details in the clearest possible way.

Download the new Instruction manual here: XB4´20 Instruction Manual

At the heart of XRAY's philosophy is a firm commitment to perfection in engineering, design, performance and support… all made possible by state-of-the-art in-house manufacturing. The XB4 is the epitome of perfection that is typical for XRAY.

Dipl. Eng. Juraj Hudy
XRAY Chief Designer

“Being part of the R&D team, I know how much time, energy, and effort is put into developing all of our cars. Chasing perfection is a never-ending process, and as such we strive to bring you an improved & better-handling XB4. You will be amazed by the handling & reliability improvements of the new XB4, which will help bring you to the Winners’ Circle.”

Martin Bayer
XRAY Factory Team driver
European Champion

Successful development of the XB4 – like all other XRAY platforms – would not have been possible without the involvement of the entire racing team working the entire year to test new ideas, prototypes, and improvements. The racing team travels to all major races around the world to provide XRAY drivers with first-class support & service so they can be assured that they always get 1st class treatment as part of the XRAY team.

The XB4 incorporates the legendary and innovative Multi-Flex™ adjustment technology, which allows tuning of chassis flex for different track conditions.

Regardless if the track has low, medium, or super-high traction, you can adjust the chassis flex to suit track conditions to gain a competitive advantage.

The graphite chassis brace – machined from high-grade graphite material – is installed in the lower part of the composite brace connected directly to the chassis. The brace reinforces the rear of the car and generates more stability while increasing traction.

The chassis brace is a vital part of the Multi-Flex™ setting.

When using the graphite chassis brace, the composite rear lower brace must be removed. 

The side guards allow the motor mount to be connected to avoid any unwanted negative flex coming from the servo in very high traction conditions.

The side guards allow the motor to be positioned as low as possible on the chassis to improve cornering speed and stability.

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

Molded from a hard composite material, the side guards are an important part of the chassis flex adjustment for the majority of track conditions. For very-low-traction tracks, optional medium stiffness side guards are available.

To improve protection against dust, Velcro® double-sided tape is included to ensure a perfect seal of the body to the side guards, to reduce the noise level of the running car.

A very handy, compact electronics plate allows for mounting the speed controller for quick & easy removal and assembly, and was redesigned to fit the new chassis and side guards.

Precision-molded spur gears are made from XRAY's exclusive secret blend of composite material, allowing the gear to run true yet be robust enough to handle high-performance brushless motors. The spur gears are designed to have the lowest possible weight while staying strong and light. Each gear is stamped with the tooth number for easy identification.

The XB4 is equipped with an 81T spur gear which suits the majority of tracks. For additional tuning, optional 75T, 78T, 84T and 87T spur gears are available.

The lowered motor bulkhead reduced the CG of the motor and central slipper clutch/diff, improving cornering speed and stability.

Machined from the premium Swiss 7075 T6, the motor bulkhead is strong and lightweight.

The correct suspension geometry is one of the most important features of any RC model car, while at the same time being one of the most difficult and challenging features for a designer.

 

The suspension is always a mixture of:

• design and shape of individual suspension parts

• flex and hardness

• materials used

• mounting system

• geometry and position of mounting points of connecting parts

 

From the suspension arms, through the suspension blocks, to the light yet robust steering blocks, every suspension part has been specially designed for the 1/10 off-road racing platform to provide responsive racing characteristics in all conditions. 

Rear suspension arms accommodate the multi adjustable uprights. The outer pivot of each arm features small screws to secure the hinge pins and prevent separation in a crash. This floating hinge pin reduces suspension bind.

The suspension arm itself is rigid enough to provide a responsive feel, yet soft enough for extreme durability. The exclusive composite mixtures used for suspension arms offer a perfect balance between reliability & performance.

There are two different suspension arms available: hard (included), and graphite (optional), each suitable for particular track conditions.

Suspension arms allow for quick & easy wheelbase adjustment. Using included 2mm shims, both front and rear suspension arms can be moved either forward or rearward to adjust weight balance depending on track conditions.

By moving the arms to the front, the balance and weight of the car are transferred more to the rear; this is recommended for medium- and high-traction conditions.

By moving the arms to the rear, the balance and weight of the car are transferred more to the front.

The tiny yet tough steering blocks are molded from a special composite mixture for maximum strength.

Composite steering block inserts allow for very quick & easy lower roll center adjustment. With additional shims and extra inserts, fine tuning the roll center is easily achieved.

For maximum drivetrain reliability, larger 5x12 ball-bearings are used in the outer position with increased dynamic load. On the inner position, the smaller 5x10 ball-bearings are used for minimized unsprung weight. 

The 1-piece caster blocks are very lightweight, yet the construction makes them very stiff and rigid. The non-adjustable caster angle is preset to 9°. Roll center position can be quickly & easily adjusted by inserting different thickness of shims atop the caster block (between the block and the vertical ball stud).

The non-adjustable caster is preset to 9°, however the position of the adjustable eccentric bushings in the I.S.S.™ suspension holders influences the caster as well. (For example, if the eccentric bushings have the roll center in middle position, the caster angle is 9° which when added to the 9° caster block gives a total of 18° caster. The total adjustability range for caster is 16-20°.)

Optional caster blocks with 6° and 12° built-in caster angles are available for further suspension geometry adjustment.

There are four different caster blocks available: medium (optional), hard (included), graphite (optional) and aluminum (optional), each suitable for particular track conditions.

The new hard caster blocks increase stability in high-traction conditions, and help to increase cornering speed.

To guarantee maximum reliability, all turnbuckles are manufactured from special HUDY Spring Steel™ material for turnbuckles which features a tougher core. These turnbuckles are used for front & rear upright linkages, steering system, and also for the servo saver.

The big-bore shocks are membrane free, but still allow for easy, consistent building and rebound setting using a bleed-screw shock cap design.

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

Shock pistons are made from Delrin® and are molded using ultra-high precision molds. All-new 2-hole pistons (1.6mm and 1.7mm holes) are now included in the set.

The all-new shock springs are shorter to allow more fine ride height adjustment especially on carpet tracks. The XB4 springs have been specifically designed to complement the big-bore shocks.

There are two types of springs in offer:

• Linear – The spring rate is constant during the entire spring compression. Springs with different linear spring rates are available as optional tuning parts.

• Progressive - The main advantage & benefit of progressive springs is that as the car initially enters the corner the springs work like softer springs to provide maximum traction. As the chassis begins to roll in the middle of the corner, the spring rate progressively increases until it works like a stiffer spring which allows the car to maintain maximum cornering speed.

XB4 springs, like all other XRAY springs, are manually measured, selected, and matched into pairs to guarantee precisely equal length and damping characteristics.
Each spring is laser-engraved with stripes to indicate the firmness; the more strips, the harder the spring.

Anti-roll bars are manufactured from special spring steel material and are included to stabilize the front & rear ends of the car. The roll bars are easily mounted to the diff cases and can be adjusted with the linkages.

Both front & rear anti-roll bars are interchangeable since they have same design and shape. The thickness of each anti-roll bar is laser-engraved for easy identification. Anti-roll bar wires of different thickness are optionally available for fine-tuning.

Ultra-lightweight 12mm wheel hex drive hubs are CNC-machined from Swiss 7075 T6 black-coated aluminum. These ultra-true hex hubs have a clamping design which ensures ultra- solid mounting of the wheel on the hub.

The rear alu hex hubs are specially machined to reduce rotating weight while guaranteeing wobble-free wheel mounting.

To adjust track-width, optional offset wheel hex drive hubs are available.

With the weight balance adjustment, the XB4 features two different battery straps: short -or- long. Using the longer battery strap, the battery pack can be installed either frontwards or rearwards; the included foam back spacer ensures the battery pack will not fall out.

Beefy 6mm thick body posts are made from special composite material for maximum strength. The body supports are rounded to have a better fit and provide better support for the car body.

To improve protection against dust, Velcro® double-sided tape is included to ensure a perfect seal of the body to the side guards, to reduce the noise level of the running car.

The XB4 includes a completely redesigned, low-profile Alpha body with super-smooth airflow and revised downforce characteristics. The Alpha body helps the XB4 by increasing steering & stability while also improving handling in jumps.

The front part of the body has a new high-downforce area. The sides of the body have upper downforce areas to generate more mid-body downforce, and the straight sidewalls improve stability. The upper part of the body was redesigned with a smooth flow channel for stability.

The XB4 bodies are available in different thicknesses for fine tuning the performance of the car.

Stylish and effective rear wing was designed to work perfectly with the XRAY XB4 body. Made from strong Lexan™ material, the wing is supported on the wing mounts by extra flat shims to better support and extend the life of the wing.

Optional thicker 1.5mm (#363511) and 2.0mm (#363512) rear wings are highly reliable with less chance of breakage, while at the same time influencing the performance of the car as well. The thicker wing gives higher traction and stability, but gives reduced steering.

The included XB4 wheels feature countersunk center area to allow the wheel nut to be positioned further into the wheel.

The wheels are perfect for high-competition racing. The wheels are made from a very flexible material, while still being ultra-durable to withstand impacts. The side of the wheel is aerodynamic for maximum performance. The wheels were designed to provide maximum traction.

Internal reinforcement ribs make the wheels as stable as possible and eliminate deformation. The wheels feature a 12mm internal hex.

The chassis design focuses on balanced weight distribution and weight transfer. The chassis features pre-drilled holes for additional weights for optimum car balancing. Centerline holes are pre-drilled for easy balancing with the HUDY Chassis Balancing Tool #107880.

All-new larger ball-bearing used in the rear uprights for increased reliability. The XB4 features greased ball-bearings for front steering blocks & rear uprights to increase lifespan in dusty conditions. The remaining bearings are degreased and oiled with AeroShell® Fluid 12 for maximum smoothness and long life.

A full set of high-speed ball-bearings are used throughout the drivetrain to ensure maximum efficiency.

HUDY Exclusive Silicone Oils are manufactured in Europe and each batch is laboratory tested and calibrated to ensure the highest possible consistency and quality from batch to batch. Based on the industry-standard cSt rating, the new line of oils will be easy to identify, adjust, and feel.

When following any set-up sheets by XRAY or XRAY team drivers, you can be sure that the oils you will get for your car are exactly same as those used by the factory racing team, thus ensuring very exacting set-ups and handling.

HUDY Chem Series.

The extensive and impressive range of adjustment possibilities includes: caster, camber, toe, kick-up, anti-squat, ride height, downstops, track-width, lower roll center, upper roll center, roll center positions, bump steer, wheelbase, Ackermann, adjustable shocks, adjustable front and rear diff and adjustable XRAY Multi-Flex™.

The XB4 includes premium #106210 HUDY Graphite Grease which is a high-performance, advanced-technology semi-fluid lubricant which incorporates both extreme pressure additives and finely-dispersed graphite for load carrying. It is intended primarily for the lubrication of rotating parts and loaded gears. In addition to providing outstanding load carrying, it is formulated to have excellent adhesion and resistance to "fling-off" under extreme conditions. The grease reduces wear and increases parts life.

The XB4 is one of the most adjustable electric off-road car in the world. Whether you are a hardcore racing fanatic or a club-level sportsman, you can very easily adjust the XB4 to suit your racing style, race track type, and all track conditions. To fully understand the set-up possibilities we recommend the legendary HUDY Set-up Book, loaded with over 40 pages of high-quality pictures and easy-to-understand RC car set-up explanations. Whether you are a novice driver or experienced racer, you can easily learn many set-up tips & tricks and improve your set-up skills, ultimately translating into improved racing performance with your XB4. The HUDY Set-up Book is available for download exclusively at www.hudy.net

Owning an XRAY model racing car is an experience on its own. Not only will you own the most premium luxury model racing car in the world, but you will also become a member of the prestigious family of XRAY owners with direct support and service from the XRAY factory. XRAY brings you the most up-to-date RC Web site on the Internet, with daily racing news and latest product developments. If you have any questions, problems or comments, you can ask the XRAY Support Team or any XRAY Factory Team Driver on the XRAY Support Forum. You can even upload your own set-up sheets or download from the thousands of different set-up sheets available from all around the world at the exclusive XRAY Virtual Set-up Sheet Database, the world’s largest set-up sheet database. And that is only the start of the VIP treatment you get by joining Team XRAY.