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Photo Credit: Cristanio Morello

Beta Motors have just dropped a proverbial bombshell with the announcement of a 125cc two-stroke enduro bike.

Playing the cards very closely to their chest, it seems Beta have caught everyone on the hop with news that they are releasing an all-new RR 125 two-stroke as part of their 2018 model range.

This is a completely new project and the result of a long development cycle which completes the entire range from 50cc bikes to big thumping 480cc engines.

The heart of the RR 125 2T MY 2018 is dedicated to competition and is targeted at the Junior and Youth categories of the World Enduro Championship and the Cadets, Junior and E1 categories of the Italian Enduro Championship, as well as all the categories reserved for small 2-strokes in the various national championships.

Beta's latest addition has Euro 4 homologation and is aimed at those who have just reached the age of 16 (though we reckon there will be many big kids wanting one too!).

The new motorcycle shown at the Press Presentation of the Enduro MY 2018 range will be presented to the public at EICMA 2017 and go into production immediately afterwards, so we’re looking at December 2017/January 2018.

 

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Photo Credit: Cristanio Morello

Engine

This is the smallest engine of the Enduro range currently produced at Beta's Rignano factory. The result of a long process of design and development, carried out entirely by the Technical and R&D Departments, it is characterised by a particular layout designed to optimise the distribution of weight and the fluid dynamics of the engine. 

The relative position of the principal components, crankshaft and gearbox drive shaft, has allowed for reducing the longitudinal dimensions and improving engine breathing under all operating conditions. In this way an engine has been created whose great linearity and progressiveness is its strength. 

This characteristic, hard to find in small engines, allows full use of the engine from the lowest revs upwards, softening the characteristic torque knock, particularly annoying in small engines with high specific power.

There are many distinctive features of this engine, including:

Double piston rings (ø 54 mm): component designed to ensure high rigidity and reliability; the choice of double rings provides a better seal at the low and medium rpm ranges typical of Enduro.

Beta progressive valve: the system derived from the RR 2T 250 and 300 cc, characterised by a particular relationship between the opening of the main flap and that of the side boosters. The delay in opening the boosters enables excellent progressiveness in performance throughout the rpm range of the engine.

Crankshaft with polyamide inserts: favouring lightness and ensuring optimum filling of the crankcase to the benefit of performance and reliability.

 

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Photo Credit: Cristanio Morello
 

Cylinder: presents an exhaust flange system like that on the larger MY 2018 displacements, enabling better control of the piston-flap-cylinder front tolerance. By keeping this value to a minimum it is possible to achieve a significant performance boost at low rpm, reducing the leakage of gases.

Aluminium dismantable cylinder head: rigid and lightweight solution made possible by moving the engine coupling on the cylinder. The geometry of the combustion chamber is designed to ensure high efficiency of the thermodynamic cycle and to obtain the best compromise between responsiveness at low-to-medium revs and in bursts. It also facilitates the fine tuning and replacement of the combustion chamber.

Die-cast crankcase in aluminium alloy: the casing geometries were designed according to an innovative layout in terms of the relative position of components and with a view to maximum weight reduction without compromising structural strength. The main bearing area received particular attention to ensure the correct rigidity of the walls in order to withstand the stresses transmitted by the crankshaft.

Die-cast crankcase covers in magnesium alloy: ensuring very low weight and optimal surface finish. It was possible to also adopt this solution for the inner clutch cover thanks to the isolation of the water pump from this element.

Vforce4 reed valve packet: the presence of the stoppers ensures high reliability without compromising performance.

6-speed dog-box transmission: specially developed for this engine with gears made by mechanical machining of forged parts so as to provide mechanical strength and reliability while still maintaining very low size and weight.

Clutch: multi-disc in oil bath with reverse opening, actuator integrated in the outer cover. This is a system designed for maximum lightness and compactness of the engine which, thanks to its low positioning, ensures the reduced size of the power unit and a significant centralisation of weight, very important for good chassis dynamics.

Electric starter: the engine is designed to accommodate (as an accessory) a Bendix start and engage starter motor, fully integrated into the layout of the crankcase in a protected position.

 

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Photo Credit: Cristanio Morello

 

Chassis

The bike derives partly from the larger engines in the range but was developed specifically to optimise the behaviour of the engine-frame combination.

The frame, in chrome molybdenum with double cradle split above the exhaust port, has been redesigned for a small engine, revising its principal dimensions and ensuring an optimal positioning of the engine.

This solution has allowed particular characteristics of the RR family to be further enhanced, such as its great handling and ride-ability – even more noticeable due to the low weight of the motorcycle – as well as stability.

Among the many innovations adopted on this motorcycle are:

Geometry of the new upper attachments: various solutions were researched and developed before the final one that made it possible to reduce the vibrations generated by the engine while maintaining significant engine-frame system stiffness.

Sachs Suspension: derived from the rest of the RR range but with its own settings. At the front there is an open-cartridge fork of 48 mm diameter.

 

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Photo Credit: Cristanio Morello
 

Exhaust system: in order to optimize the 2-stroke engine's torque and power curves, the Beta R&D Department has developed a special system dedicated to Enduro use.

Filter box manifold: designed for the 125 cc engine, it improves the flow across the range of operation, from low revs upwards.

Engine guard: made from polyamide to combine strength and lightness, it provides excellent shielding against the ingress of mud between the engine and the guard.

Gasoline tank: a slightly smaller tank has been adopted to improve ergonomics on board the bike while maintaining sufficient fuel autonomy.

Cooling system: designed especially for this bike, it has new pipes and radiators with specially shaped reservoirs to fit the small size of the motorcycle.

Nissin braking system: extremely powerful and configurable, the same as on the rest of the Enduro range.

Colours and graphics: the same as the rest of the RR my 2018 range.