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RR 4T 350 EFI/390/430/480

RR 4T MY 2015

The Beta RR Enduro project continues to grow and improve, boosted by successes on the racetracks and by the great commitment of the technical and R&D departments in Rignano sull’Arno. The RR Enduro 2015 models are lighter and more agile, and their great power and torque are more easily controlled. They are the ideal bikes for enthusiasts and the winning solution for victory-hungry racers.

The RR Enduro 4T 2015 range evolves with updates to all models of the “RR 4T Factory MY14” version and the introduction of many new technical features. The main objectives during development were to make the bike lighter and easier to control, and improve overall handling making it more enjoyable and easier to ride and, above all, more effective. The engine-block components have been made lighter and redesigned to reduce the inertial masses, and the engine sizes have been reduced to make handling easier and minimise weight. Compared with the larger capacity of the previous model, the absolute power and torque figures remain unchanged thanks to a new camshaft profile and a new exhaust system; in addition, a better distribution of the torque curve has been obtained to get more out of the engines.

Electronic Injection System

The main innovation of the RR Enduro 4T 2015 range is the electronic injection system mounted on the 350 model. The system was developed together with Synerject and has a 42 mm-diameter throttle body. Electronic injection ensures precise carburation control under all usage conditions, the air-petrol mix is optimised for any altitude thanks to a temperature and pressure gauge. The engine offers immediate and smooth response with any driving style. Also, thanks to the adoption of a stepper motor mounted on the throttle body, an accurate minimum rotation speed and a reduced engine braking are always guaranteed.


The whole range is equipped with engines that have been completely renewed, both in terms of looks and performance. The total weight has been reduced by 1kg on the 430 and 480 engines, compared with the previous 450 and 498, and by as much as 1.5kg for the 350 (derived directly from the 2014 factory model) and the 390 (which will replace the 400). The central guards have been completely redesigned, made lighter and modified internally to house a new oil-pump drive system, which is simpler and more effective thanks to elimination of a drive gear. The flywheel chamber has been redesigned in order to minimise pumping losses, and the entire shape has been reworked thanks to the introduction of ribs that stiffen the engine block. The covers, clutch and flywheel have also been modified with a view to reducing weight and, at the same time, increasing the rigidity of the parts themselves.

  • The crankshafts have new shoulders and a new con rod, lighter and with optimised inertia, making the bike quicker to deliver power and more agile thanks to a reduction of the gyroscopic effect.
  • More specifically, the con rods are shorter and lighter, and feature a new design. The redesign is aimed at reducing the alternating masses and the size of the engines. The 390-430-480 cc engines, in fact, have the entire combustion unit positioned lower down compared to the previous models. This means that masses are more compact and closer to the centre of gravity, significantly improving the bike's agility.
  • The piston is lighter and more robust, thanks to a structure derived from Formula 1 called “box-in-box”, which enables a reduction in vibrations and an increase in performance. The gudgeon pin is coated with a Diamond-Like-Carbon (DLC) treatment to minimise friction and wear.
  • The camshafts were developed with a new profile to boost performance, especially at low speeds, and to provide greater linearity of output. On the 350 and 390 version has been adopted a complete set of titanium valves.
  • The cylinder features a new design for the water jacket to improve the removal of heat and increase the efficiency of the whole cooling system. The head has been completely redesigned both in terms of the conduits and combustion chamber, in relation to the needs of the new engine sizes, and externally.
  • The starter motor has been significantly improved and is more powerful and lighter compared with the previous models. The balance shaft has been completely redesigned in relation to the different balancing of the primary masses of the crankshaft unit; the result, also here, is a significant reduction in weight. The intake sleeve has been completely redesigned for the new engine sizes to guarantee better fuel supply, optimal filling of the engine and therefore a better yield, particularly at low rotation speeds.


The silencer has been redesigned with new internal passages and a larger diameter of the manifold connection hose. The performance and precision of engine response have increased considerably, bringing them as closely in line with the different fluid dynamics imposed by the revision of the engine sizes and the combustion unit as possible.


The Sachs USD ? 48 fork developed in close collaboration between Beta and Sachs features numerous important innovations: a new design of the extension piston with “three slot” geometry in order to improve the oil flow and make it more direct so as to absorb violent shocks more progressively. To improve the general smoothness of the fork, particularly on the initial breakaway friction, a spring-support release system has been included to eliminate rotational friction, the design of the sleeves and sheaths has been modified increasing the distance between the slider DUs, also reducing their height. Finally, the spring profile has been redesigned to guarantee better insertion inside the sleeve. All the connections have also been adjusted, increasing precision.

Shock absorber

Ideal for the most extreme off-road riding and compliant with the standards required by FIM regulations.

Handlebar pads

Ideale nella guida più estrema in fuoristrada e conforme agli standard richiesti dalle normative FIM.


The padding has been redesigned with softer foam


The renewed look streamlines and adds character, maintaining the classical Beta colours.