Merlin Motorcycles Trials Bikes & Parts Service

Worldwide mailorder from England   phone/fax 01403 257626  
 Email MerlinMotomerlin shop | Ebay shop | Facebook | Moto blog | Merlin Books

Merlin Books

Off Road Books 


Visit our Ebay shop
for more bargain Books & bike parts

We accept Visa & Mastercard & now accept payment via


 PayPal or see  order page


Gas Gas Enduro
Gas Gas Trials
Gas Gas Pampera
Gas Gas Supermoto
Beta Rev3 Trials
Beta Alp 200/350
Beta M4 Supermoto
Beta RR Enduro

Full on line web shop coming on links below for a taster!

Trials Parts:
(more products are being added all the time)
Air Filters
Bargain Bin
Beta Parts
Bike Stands
Boyesen Reeds
Brake Pads
Bultaco Parts & Books
Domino Throttles
Electrical Parts
Everything Else
Fork Seals
Gas Gas Parts
Handlebars & Levers
Hebo Parts
NEW Hebo Trials Clothing
Jitsie Clothing
Jitsie parts
Montesa Parts
Pre 65 Classic Trials DVDs
Silencer Exhaust parts
Scorpa Parts
Sherco Parts
Trials Books
Trials DVDs
Tyres, Tubes, Pumps & Gauges
Supermoto Wheels etc

Used Bikes/Free Ads

Riding Tales
Our Trials Photos
Video Preview

Email Motomerlin
About Motomerlin

Secure orders
via Merlin Books

Merlin Motorcycles
P.O. Box 153
West Sussex
RH12 2JG
Phone 01403 257626
Fax     01403 257626

VAT Reg No:
GB 515276257

Merlin Books more Motorcycle books


This site is 
© Mike Husband t/a Merlin Books & Merlin Motorcycles 1996 - 2008

Website design by 
Mike Husband

2009 Beta Evo Trials

All New Model
S3 Titanium pipes for Evo - coming soon..

From 2009 Beta Evo Trial

Beta's proven experience over many years in the trials field (both in competition and production) has enabled us to develop an innovative design, light years away from the standards that have defined the concept of the “trials bike” up to now .EVO (an abbreviation of evolution) achieved that objective with results exceeding even our highest expectations. We have built a bike aimed to represent the state of the art in lightness and dynamism. Starting from the frame design, we developed a brand-new concept, unheard-of in today’s trials bikes, and built the EVO around it.

Here-below you will find the main technical features of 2009 models both in 2 stroke version, available in 125cc, 200cc, 250cc and 290cc, and in 4 stroke version, available in 250cc and 300cc. For a rapid information here-enclosed we are sending you the main techincal notes and a fist image of the new bike that we ask you to consider as provisional considering that we are optimizing the graphics. Soon will be available also a dedicated leaflet.


<>Everything turnes around the new frame, a single-beam aluminium chassis which simultaneously provides maximum rigidity and reduced weight, meanwhile representing the bike’s bone-structure and functioning as its  fueltank. Another important change, which development has required a long time, a weight shift towards the bike’s centre of gravity, raising it at the same time, in order to improve the bike’s dynamic behaviour. Here, too, the results were striking. <>The redesigned cycle parts strongly contributes to improve riding feeling. Key element is in this case is the shockabsorber with progressive linkage, to centre the masses along the EVO’s longitudinal and transverse axes.
A completely new bodywork, designed paying particular attention to ergonomics and to overall dimensions reduction, is another important peculiarity.
<>The 2-stroke engine’s 290cc capacity is an absolute novelty, as well as  its positioning in the frame, being allocated higher than in any of its 2-stroke or 4-stroke predecessors.
The 2-stroke engines are equipped with a dismantlable cylinder head, a new generator with dual mapping and a new exhaust system with an expansion box first chamber.

The 4-stroke engines are equipped with a dual mapping control unit and a new exhaust system with a three-chamber mechanical silencer to combine performance with reduced noise output.



Cycle parts

  • The innovative character of the single-beam aluminium frame, with its integrated fueltank, is clear from the design configuration, based on a principal beam formed by extrusion. That houses the fuel supply, with forged cross-pieces front and rear completing the structure.

This conformation enables us to make optimum use of metal thicknesses and sections at points of maximum stress (finite element analysis was used for the frame calculations). This also allows us to achieve our targets in terms of lightness, rigidity and compactness.

  • The 38 mm forks are also new. They are the result of exclusive joint development by Beta and Paioli. The redesigned fork inner components  are distinguished by the extensive use of light alloys and by sophisticated management of extreme hydraulic effects (damping). This is all fitted into a very light and compact design, with a 600 gram saving in weight. The result is a smoother and more progressive operation compared to any front suspension we have used in the past.
  • An important and characteristic feature is the super-light aluminium fork yoke, 150 grams lighter than in the past, fitted with pivoting single-fixing handlebar risers for easy and quick maintenance.
  • The EVO’s wheels have been lightened, with new aluminium spoke-nipples, and lightened wheel-spindles fitted with more compact wheel bearings.
  • Another new component is the aluminium swing-arm, which works by means of a progressive leverage system. This important element was designed by Beta’s R&D department, using extruded and hydroformed rails. This is a process which shapes the part by water-pressure, with a view in this case to correct distribution of thicknesses so as to limit weight and increase rigidity.
  • We have already mentioned the new monoshock with aluminium body. We should add that it has adjustments for spring preload and rebound damping.
  • The rear brake system has been designed from scratch for EVO. The object was to reduce bulk and weight, at the same time increasing braking efficiency and precision. The rear master cylinder and its mounting to the frame are new, as is the caliper and its fixing system to the swing-arm. Furthermore, both the 160 mm diameter disc and the brake pedal are new.
  • The engine protection plate is more rigid than in the past thanks to the insertion of reinforcing platelets between the frame forgings and the plate itself, the most stressed point.
  • The electrical wiring system has been completely revised.
  • The radiator is the result of fresh research. It now uses a different coolant circulation layout, designed to ensure greater cooling efficiency. It has a new temperature sensor, directly mounted on the radiator.
  • The air filter box also is based on a novel design concept, aimed at minimising pressure drops on the intake stroke and so maximising performance.



·         The choice of 290cc cylinder capacity was dictated by the search for greater versatility in use, to satisfy both competition riders’ need of performance and leisure riders’ request for more power and torque at low revs.

The power plant is located noticeably higher than in our earlier models, because of the benefits this brings to the bike’s dynamic behaviour by optimising the position of the centre of gravity.

·         The generator with its external pickup is new, with a higher power output and a programmable control unit with dual mapping (soft and racing) selectable by means of a switch.

·         The ignition casing has also been reshaped to accommodate the new ignition components.

·         The combustion components have been redesigned: the cylinder head can be dismantled into two pieces.

·         The conrod and the new piston are forged. Result: 30% less weight, to reduce reciprocating masses, and a noticeable reduction in engine vibration.

·         Finally, the exhaust system has been reconfigured to feature an expansion chamber which combines better performance with an audible reduction in noise output.

The two stroke models wil be available from the end on October, the four strokes in December. Prices are TBA, but expect a small increase on last year's.

From 2009 Beta Evo Trial


Frame   Single  wave aluminium beam
Wheel base   1305 mm
Max length   1990 mm
Max width   850 mm
Max height   1115 mm
Seat height   660 mm
Ground clearance   310 mm
Footrest height   345 mm
Dry weight   69 kg
Fuel tank capacity   2,6 l.
Reserve   0,5 l.
Cooling system capacity   600 cc
Front suspension   Hydraulic fork with ø38 mm shaft  
Rear suspension   Monoshock
Shock absorber stroke   60 mm
Front wheel travel   165 mm
Rear wheel travel   180 mm
Front brake   disc ø185 mm with 4 piston caliper
Rear brake   disc ø160 mm with 2 piston caliper
Front rim   21 - 1,6 - 32 holes
Rear rim   18 - 2,15 - 32 holes
Front tyre   2,75 - 21
Rear tyre   4.00 R 18

ENGINE  EVO 250 two stroke
Type   Single-cylinder, 2-stroke, liquid cooled,  lamellar induction in the crankcase
Bore   72,5 mm
Stroke   60,5 mm
Displacement   249,7cc
Compression ratio   8,9:1
Ignition   Electronic AET 12V - 85W
Spark plug   NGK BR7ES
Lubrication    mix with fuel  1,5 %  (synthetic oil)
Feeding   with carburettor
Carburettor   Keihin PWK ø 28mm
Spark advance   Variable
Clutch   Wet multi-disc clutch with cush-drive rubber
Primary trasmission   Z. 20/71
Transmission   6 speed
Secondary trasmission   Z. 13/41(or 11/41 depending on the version)
Engine oil   SAE 20/30 (550cc) 




Frame   single wave aluminium beam
Wheel base   1305 mm
Max length   1990 mm
Max width   850 mm
Max height   1115 mm
Seat height   660 mm
Ground clearance   310 mm
Footrest height   350 mm
Dry weight   72 kg
Fuel tank capacity   2,6 l.
Cooling system capacity   600 cc
Front suspension   Hydraulic fork with ø38 mm shaft  
Rear suspension   Monoshock
Shock absorber stroke   60 mm
Front wheel travel   165 mm
Rear wheel travel   180 mm
Front brake   disc ø185 mm with 4 piston caliper
Rear brake   disc ø160 mm with 2 piston caliper
Front rim   21 - 1,6 - 32 holes
Rear rim   18 - 2,15 - 32 holes
Front tyre   2,75 - 21
Rear tyre   4.00 R 18

ENGINE 30 four stroke    BETA
Type   Single-cylinder, 4-stroke, 4 valves, liquid cooled
Bore   84 mm
Stroke   53,6 mm
Displacement   297,3cc
Compression ratio   11,0:1
Ignition   Electronic 
Spark plug   NGK CR7EB
Feeding   with carburettor
Carburettor   Mikuni 
Spark advance   Variable
Clutch   Wet multi-disc clutch 
Primary trasmission   Z. 18/63
Transmission   5 speed
Secondary trasmission   Z. 11/42