Track Testing: Tony ROK

Why a Tony ROK

After months of organization and setting up of the new “Track Testing” column, me and my photographer managed to visit the great Tony Kart Company and collect our Tony EVR ROK  engine kart. We have chosen this solution as it seems one of the easiest ways to start karting with a very performing chassis (Tony Racer EVR) and a very reliable TAG 125cc two-stroke engine (Vortex-Rok).

From 2003, the year of its establishment, until today the Rok Cup has won the trust of many fans in more than 35 countries all over the World. Rok has been a good novelty since it has been the first real single make solution directly followed by the company.  Start has been in Italy at first, then in Europe. After that it crossed the oceans and has arrived in South Africa, Asia and America. All the national champions, in every category, win the possibility to race in the Rok international Final, which is the CIK-FIA event closing the Rok season every year. The 280 best Rokkers coming from all over the World take part in this race and in the end we discover who the absolute champion in each category is: Rok, Super Rok, Junior Rok and Mini Rok.

Rok engines

Rok engines are a complete family of four different versions for the same number of classes: Mini Rok, Junior Rok, Rok and Super Rok. Mini Rok is the entry level for very young drivers. Vortex has developed two Mini Rok engines:
Mini Rok MINI 60 and Mini Rok BABY 60: the two versions differ from one another in carburettor and exhaust.

MINIROK BABY 60: supplied with carburettor of 14mm diameter and baby exhaust (reduced power), dedicated to the youngest; it is the entry level in the karting world.

MINIROK MINI 60: supplied with carburettor of 18mm diameter and mini exhaust; it is the second step in competitions, usually from 9 to 12 years old drivers.

 Rok range


We have decided to go for the ROK for our track testing since it is a good compromise between performance and reliability. To my opinion it probably represents best the aim of Vortex in creating the ROK World.

Junior ROK and ROK are based on the same engine except for the exhaust curve. Engine is a 125cc single-cylinder 2 stroke with reed valve admission in the crankcase. It is mixture lubricated and liquid-cooled with integrated water pump. It is offered with a digital ignition and an integrated electric starter, which uses a dedicated battery. It is provided with a balance shaft which reduces vibrations. A centrifugal dry clutch makes it possible to keep the engine on even when the kart is still.


Mini ROK Junior ROK ROK Super ROK
Bore (mm) 42.10 54 54 54
Stroke (mm) 43.00 54 54 54
Displacement (cm3) 60.00 123.95 123.95 123.95
Cooling Free air liquid liquid Liquid
Intake Piston port Reed valve (length 63.5 mm x height 25.5 mm) Reed valve (length 63.5 mm x height 25.5 mm) Reed valve (length 69.5 mm x height 25.5 mm)
Max torque (Nm) 19.6 at 10,000 19.6 at 10,000 20.2 at 11,500
Max power (HP) 10 at 10.300 19 at 11.500 29 at 10,500 36 at 12,500
Max revs 13,800 13,800 16,700
Carburettor 18 mm (14 mm for Baby ROK) Dell’Orto VHSH 30 mm Dell’Orto VHSH 30 mm Dell’Orto VHSH 30 mm
Fuel pump Dell’Orto Dell’Orto Dell’Orto Dell’Orto
Exhaust system With intake sylencer With integrated silencer and depower system With integrated silencer With integrated silencer
Drive Centrifugal Dry clutch Centrifugal Dry clutch Centrifugal Dry clutch Centrifugal Dry clutch
Lubrication 2-3% (Rok Lube or Elf 909 HTX) 3-4% (Rok Lube or Elf 909 HTX) 3-4% (Rok Lube or Elf 909 HTX) 6% (Rok Lube or Elf 909 HTX)
Weight 8kg 17,5kg 17,5kg 15 kg
Ignition system Electronic Selettra or PVL Electronic PVL Electronic PVL Electronic PVL
* Price (in Euro) – with carburettor, fuel pump, exhaust muffler, radiator & supports, thermostatic valve, cooling system pipes, on-off push-button panel, battery, battery support, electric plant, intake silencer. 1,950 + VAT 1,950 + VAT 2,400 + VAT

Prices are only indicative and subject to changes.


Super ROK is the ultimate evolution of the ROK engine by Vortex, conserving many of its important characteristics, but featuring an amount of innovations. Not changing the displacement of 125cc and the reed admission in the crankcase, the reed block is now bigger, and the carburettor is still a 30mm diameter VHSH by Dell’Orto. The new cylinder, always with liner, has a 5-transfers scavenging, and the 3-ports exhaust is provided with pneumatic power valve. The digital ignition has a different advance diagram; the exhaust plant is new in design with integrated silencer; the rotor of the centrifugal clutch is now monolithic.

The Chassis

RACER EVR Tony Kart freno BS7

Together with our Rok engine we have chosen one of the most performing and successful chassis from Tony, the RACER EVR. This chassis is available for both KF and KZ categories and represents the natural evolution of the EVXX the chassis that allowed Tony Kart to win all the most noble CIK-FIA competitions, including the World Championship, in these last years. The EVR is composed by a frame realized with Ø 30 mm tubes, which determine the kart to be more “free” when exiting corners. The Racing version is equipped with the new M4 bodywork and the new WTD (Wind Tunnel Design) stickers. The design of the new plastics resulted from several hours spent in the wind tunnel. The plastics have been optimized in order to reach an optimal aerodynamic penetration and to allow the air flow to invest the engine, the radiator and the brake systems in the best way during the races.

Homologation : CIK FIA 56/CH/14
Frame diameter : 30 mm
Wheelbase : 1050 mm
Stub Axles : OTK HST
Braking System : OTK BS5 – BS6 – BS7
Steering wheel : OTK rivestito in alcantara
Wheels : OTK MXP in Magnesio
Side Boxes : OTK M4
Seat : OTK a fondo piatto


This top chassis is provided with OTK magnesium accessories. The OTK brake systems BS6 and BS7 are still one of the most important features characterising both the former model and the new one. Front brakes are also included and will be tested to understand if and when these brakes are useful and performing for a driver.

Base setup for Tony EVR is neutral height front and rear and neutral camber and caster. Front torsion bar must be flat and rear bar eliminated. Rear carriage width will be to maximum limit at 140 cm and front carriage width will be adjusted with a small and a large spacer, equal to 2.5 cm additional width. Convergence must be 1 mm “open” at the front, so 0.5 mm per side. Seat will have stiffness bars o both sides, at least one, possibly two per side.

Rear axle stiffness is determined by five different materials indicated on the axles as HH, H, N, Q and U, starting from the stiffest to the softer. Base setup uses the N axle.

Prices of EVR chassis is 4,490 Euros VAT included, including front brakes, magnesium accessories and seat (price only indicative and subject to changes)