Kart Classes Explained

Kart Classes Explained


Karting has classes for boys and girls for every age, size and ability from age 8 upwards, but sometimes the sheer number of options can be somewhat confusing.

In short, there are five different categories and within each category there are different types of engine that you race with

· Bambinos: for Age 6-8th Birthday

· Cadets: Age 8 – 13

· Juniors: from 11- 17

· Seniors: 16 and up

· Gearbox for karts with gears. The non-gearbox ‘direct-drive’ karts only need to have a brake on the rear axle whereas gearbox karts must have brakes operating on all four wheels.The modern direct-drive karts have a centrifugal clutch so the engine can tick-over.

Bambino: Age 6 - 8th birthday 

You can start in Bambinos between your 6th and 8th birthdays.The karts and engines must be registered with the MSA (motor sport association), and the driver must be signed off as competent by an ARKS Instructor or Examiner before taking part in an MSA event.  Only time trials are permitted, the karts leave at set intervals on specially approved mini circuits, and are timed.  The drivers are graded into Gold, Silver and Bronze categories and their record cards updated.  Everyone will receive a certificate of attendance.  The only engine allowed is the Comer C50 with a logbook from Zip Kart, and the only tyres are Le Cont all-weather.

Cadets: Age 8 - 13 

Boys and girls can start racing karts at the age of 8 in one of the Cadet classes, although some tracks will allow youngsters to practice from the age of 7. They can continue until the end of the year of their 13th birthday, although they may be getting too heavy by then and so can move into certain junior classes from the age of 11. The three Cadet classes are described below and all are permitted to race together. All have a centrifugal clutch and a recoil starting cord. The special minikarts used are registered with prices controlled to an agreed maximum. Top speed is about 50mph.

IAME Cadet uses a 60cc unsealed 2-stroke Parilla Gazelle UK engine, new for 2013.

Honda Cadet uses a 4-stroke Gx160 engine which no longer has to be sealed. The long life engines are very low-cost but have to conform to a technical specification which is on the www.abkc.org.uk website. Most but not all clubs will accept these karts and it has a national ABkC championship in the Super One.

The Super One Series holds the British Cadet Championship for the IAME Cadet class, and the National Championship for the Comer Class, and the ABkC National Championships for Honda Cadet, Rotax and TKM Classes.

Juniors: Age from 11,12 or 13 depending on class up to 17 

The 125cc water-cooled Rotax Max TAG (Touch and Go - electric start) categories are now the most popular classes in the UK.

Drivers can start racing in Rotax MiniMax at age 11, then move into the more powerful Junior Max at age 13. Being a TAG class, the Rotax have a press button start.

Rotax are more expensive initially but the engine runs longer between rebuilds, so the running costs can be less. Top speeds in the junior classes vary from 55mph to 75mph. Drivers in the 11 year old junior classes must weigh a minimum of 38kg with suit, helmet and boots.  At 13 it is usually 40kg for the more powerful classes.

Rotax MiniMax (age 11-15) is the lowest powered class of the Rotax family, and uses a very restricted 125cc 2-stroke TAG engine. All Rotax engines are sealed and have a log-book showing the service history.

Junior Max by taking the restrictor out of a MiniMax it is converted to a Junior Max (age 13-17 yrs). It is one of the most powerful junior classes, with top speed about 70 mph.

Junior TKM (age 11-17) is a popular traditional kart class using a BT-82 piston-port engine to a strict non-tuning regime.  The junior engines have a choice of restrictors between the carburettor and the engine to limit the power, the choice depends on the driver weight.

Junior TKM 4-Stroke Tal-Ko, who make the TKM engines, also make a 200cc long-life 4-stroke. Not raced at most clubs currently. For 11- 17 yrs with a senior equivalent.

Formula KFJ (KF Junior formerly KF3) The premier British championship class for 13-17 yrs (12 for experienced drivers), also raced at European leve,l not a class for the inexperienced. This is the Junior British Championship class held in the Super One Series.

Junior TKM Extreme A faster 115cc class for championships, having three weights each with a different restrictor size, all with a clutch. Not raced at clubs.

Junior 4-stroke classes There are other 4-stroke classes for Junior and Seniors which run at certain clubs only e.g. Honda classes and World Formula (senior only). More information on http://www.abkc.org.uk/startkart.htm

Seniors Age 16 upwards 

The most popular senior class in the country is Rotax Max, but there are other options worth exploring at your local circuit. The once all-conquering TKM Extreme class is now only popular in certain areas, eg in the Midlands, and if you live in such an area it should be investigated. There are other TAG engines as well as Rotax, and TKM has a senior 4-stroke class. Once some experience has been gained there are further options for the premier international classes, raced primarily at the major championships. These KF class use a variety of 125cc TAG engines, similar to Max. KF is unlikely to be seen at club level. They are restricted in maximum rpm for longer life. Both are raced in the Super One Series with KF being the MSA British Championship. Senior classes top out at 85mph.

TKM Extreme is for 16 yrs upwards (although as in all the classes juniors already racing may move into the senior classes in the year of their 16th birthday). The engine is a115cc variant of the BT82. As with the juniors the chassis have to be registered, and new designs are only permitted every three years, to keep costs down. It’s a popular and economic class and now has a TAG option.

Rotax Max the senior equivalent of Junior Max, with a very powerful 125cc TAG engine. Although the maximum revs are limited electronically, they are nearly as quick as KF2, but much lower maintenance, and sealed to prevent unapproved tuning. Care needs to be taken if starting in this class. Like many classes there is a higher weight variant called Rotax 177 for the heavier driver.

KGP and X30 These are new classes, KGP Pro has a national series in the Super One but KGP Junior and X30 Junior and Senior are only permitted to have club championships.

Senior 4-stroke classes There are other 4-stroke classes for Junior and Seniors which run at certain clubs only e.g. Honda classes and World Formula (senior only).  More information on http://www.abkc.org.uk/start-karting/

Gearbox Age 16 upwards (Junior 13 - 17) 

Other than the Junior 85cc category for 13-17 year olds, gearbox karts offer the highest powers and speeds. They can have either 2 pedals - brake and accelerator - like the direct drive classes, or 3 pedals, one of which is a foot clutch, like a car. Most 125’s use karts very similar to the direct drive karts except for the four wheel brakes. They have a hand clutch mounted next to the steering wheel, which is only used to move off from a standstill. At most circuits a standing start is used, as opposed to the rolling formation start that direct drive karts have.Gearbox karts can also be used on the long motor racing circuits, although everyone should preferably start on the short circuits which are typically 900 to 1300 metres in length.

KZ UK is the most popular gearbox class. Although a little more expensive than a direct drive class, they can be surprisingly economical to run. The 125cc water cooled engines have six gears, sequentially operated like motorcycle using a gear-lever mounted next to the steering wheel. 0-60mph times are less than 4 seconds, top speed is 90mph on short circuit, 110 - 120mph on long circuit. The ABkC championship is promoted by the NKFand there are now support races for the class in the Super One Series. KZ1 is virtually the same but with more rigid regulations to CIK standard, and is the MSA British Kart Championship class in the Super One.

Junior Gearbox this class uses an 85cc Honda or TM engine with 6 gears and is for 13-17 yrs. With its four wheel braking it offers the youngsters an experience close to a single seater race-car. It’s not raced much at all now though. Currently not being run at any club.

250 National this is the most powerful short-circuit class using 250cc single cylinder motocross 5- speed engines. The karts are often equipped with large full width nose cones and wings, especially when used on the long circuits. Top speeds are 100mph on short circuit, 140mph on long circuit. Twin cylinder Superkarts can reach 170mph though. The NKF holds the ABkC national championship. Some clubs offer the 450cc 4-stroke engine class which may be raced in parallel with 250 National but for separate prizes.

210 National a classic class using the Villiers 197cc engine or derivatives. Administered by the drivers themselves through the 210 Challenge group