Kyosho announces the new Ultima RB5 electric racing buggy. It’s a virtually all-new design that is the result of years of R&D and includes the collective experience of the world’s most experienced RC racing drivers and engineers from the world’s most experienced RC racing company. The main goal of the new Ultima RB5 is simple – to win the next IFMAR World Championship.
The new Ultima RB5 only shares rear hubs with the Lazer ZX-5 and a few common hardware items, but the essential and distinguishing components of the car, such as the chassis, transmission, bulkheads, shock towers, suspension and the sleek aerodynamic body, are all new. Each aspect of the car is specially designed and tested to produce maximum performance. Likewise, the materials chosen for this new Ultima are exhaustively tested – all with the goal to create the ultimate no-nonsense competition car that’s ready to take on the world.
The chassis plate is light and strong, featuring a specially formulated carbon fiber composite for the best balance of performance and durability. Strategic braces molded into the chassis enhance the stiffness without adding any unnecessary weight. Separate front and rear “clips” allow fast and easy removal of the front or rear end of the car, which makes maintenance and repair much easier. Designed to accept stick packs and racing-style 6-cell matched packs, the RB5 chassis features an adjustable battery mounting position that allows you to shift weight bias to suit track conditions and your driving style.
The new transmission features a smaller, more compact housing that keeps the motor as low and close to the transmission as possible, which reduces CG and improves bump handing. The three-gear transmission features an internal ball differential that uses standard 3/32-inch diff balls and 1/16-inch thrust balls. The differential is also externally adjustable, and a dust cover fits over the adjustment holes so the thrust bearing lasts much longer. An injection molded gear cover is included, which better fits the motor plate to minimize dust and debris for longer gear life.
The rear suspension arms are symmetrical so a single replacement arm can be used on either side of the car, saving money and space inside your pit box because you don’t need to carry as many replacement parts. The inside of the arms are attached to the chassis using separate suspension mounts, which will allows anti-squat adjustment. The rear wheel hubs feature three lower hinge-pin holes, which allow modification of the ride height with minimal disturbance of the suspension geometry. Vertical ball studs for the both the inner and out rod ends of the upper link mean the rear suspension geometry can be fine-tuned with shims.
Longer, straighter and symmetrical suspension arms connect to a narrow front bulkhead. The bumper/skid plate, suspension block, nose plate and front bulkhead all come together to form a very rigid assembly, to which the front suspension arms mount. The standard position of the suspension mount produces 25 degrees of hinge pin angle in the front suspension arms, but simply flipping the suspension mount increases the hinge pin angle to 30 degrees. The added flexibility of having adjustable hinge pin angles means you have more options when it comes to setting up your car. Like the rear arms, a single replacement arm can be used on either side of the car.
Offset steering hubs make high-speed handling a dream, while floating axles ride in bearings that are mounted in the hub instead of the wheel This moves the weight of the bearings inboard for more responsive suspension, the bearings are under less stress, and they’re better shielded from the elements. This means the front wheel bearings last longer and run smoother. The front track width is also easily adjusted, which means the amount of steering response is easily increased or decreased for track conditions and driver preference.
Ball bearings provide smooth movement of the steering bellcranks, which are mounted on the chassis at the same angle as the suspension arms. This eliminates bump steer and produces more accurate Ackerman geometry throughout the entire range of steering motion. The steering plate (center link) features horizontally mounted ball studs, which mean Ackerman can be fine tuned using shims behind the ball studs, offering a nearing infinite range of adjustment.
Captured Hinge Pins – A simple button head screw captures all the outer hinge pins of the Ultima RB5. The rear inner hinge pins are truly captured between the suspension mounts, and the notched inner front pins are secured with a setscrew through the front suspension mount. This means that the hinge pins are much more secure and less likely to come loose.
Low-Profile Shock Towers
The front shock tower is mounted as far back on the chassis as possibly, as are the shocks, to keep the mass as low as possible. Likewise, the rear shock tower is also designed to keep a low profile, yet allow enough suspension travel to ensure the best possible handling. The shock towers are molded from an exhaustively tested composite, which is much more costly to produce than shock towers made from woven graphite, but will also provide greater durability.
Threaded Aluminum “Triple” Shocks – Kyosho is well known for silky smooth shocks and the new “Triple” shocks included with the Ultima RB5 are no exception. The shock body consists of three major components – a top cap, threaded body, and a lower cap. The aluminum shock bodies feature a threaded spring pre-load collar for quick and easy adjustment. The threaded adjuster features an O-ring that prevents the preload settings from moving, which ensures consistent performance from start to finish. The lower shock cap allows quick and easy maintenance of the double O-ring seals.
no less than ten versions of the new body for the RB5 were thoroughly tested to maximize performance and to ensure that you have the best-looking car on the track. The entire R&D team as well as the factory drivers were involved in the development, and the finished product is the best-performing body ever used on a 2WD buggy according to the team.
Category: 1:10 competition 2WD electric buggy
Wheelbase: 10.63 in. (270mm)
Track width: 9.84 in. (250mm)
Weight: 57.2 oz. (1620g)
Chassis: Molded carbon composite
Transmission: Compact 3-gear
Differential: Externally adjustable ball-type
Transmission ratio: 2.6:1
Slipper: Double-disc, spring-loaded
Bearings: Teflon-sealed (transmission); metal shielded
Suspension: Lower H-arm w/steel turnbuckles
Shocks: 3-piece threaded aluminum, oil-damped
Driveshafts: Steel CV-type