Kart Classes Explained Karting really does have classes for almost every age, size and ability from age 8 upwards, but sometimes the sheer number of options can be somewhat confusing. This pictorial display should help to explain. There are basically four different categories - Cadets, Juniors, Seniors and Gearbox for karts with gears. The non-gearbox ‘direct-drive’ karts only need to have a brake on the rear axle (although some top classes have a front brake too) whereas gearbox karts must have brakes operating on all four wheels. Most of the modern direct-drive karts have a centrifugal clutch so the engine can tick-over.
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6 - 8
Boys and girls can start in
Bambinos from their 6th birthday
to the end of the year they turn 8. The
karts and engines must be
registered with the MSA, 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.
Their is a MSA Bambino
Championship promoted by Zip Kart, see
The only engine allowed is
the Comer C50 with a logbook
from Zip Kart, and the only
tyres are Le Cont
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.
Super One Seriesholds the British Cadet Championship
IAME Cadet class, and the
National Championship for
the Comer Class, and the
ABkC National Championships
for Honda Cadet, Rotax and
TKM Classes. IAME Cadet Uses a 60cc
Parilla Gazelle UK engine,
new from 2013. Because this is the class used for the premier championships, it is run by most clubs.
Honda Cadet 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.
Super Cadet For ages
from 11th year to 14th year,
this class is hardly ever
raced at the moment.
Juniors Age from 11/12/13 depending on class up to 17
There is no doubt that the 125cc water-cooled Rotax Max TAG (Touch and Go - electric start) categories have taken over as the most popular classes in the UK from the more traditional 100cc air-cooled two-stroke that is Formula TKM. Drivers can start racing in Rotax MiniMax or Junior TKM at age 11, then move into the more powerful Junior Max or Junior Extreme at age 13. Being a TAG class, the Rotax have a press button start whereas the TKM have to be either lifted and pushed, or use an optional plug in portable electric start box.
But from 2009, TKM also
offer a TAG option. Rotax are more expensive initially but the engine runs longer between rebuilds, so the runningcosts can be less. The TKM’s are at the economy end for initial purchase with strict price controls.
The new from 2014 X30 classes are
also beoming very popular at some clubs. Top speeds in the junior classes vary from 55mph to 75mph. The best advice here, as in all classes, is to visit your local circuit to see what is popular in your area.
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 MiniMax (11-15 yrs) 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 Junior TKM (11-17 yrs) 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
currently. For 11- 17 yrs with a senior equivalent.
Junior X30 A new class for 2014, using a TAG
unsealed engine and offering similar performance to
(KF Junior formerly KF3) The premier British championship class for 13-17 yrs (12 for experienced drivers). Also raced at European level not a class for theinexperienced.
This is not currently raced in the UK but
may start in the Super One with the new OK engines from
The junior classes all have more powerful senior equivalents. 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.
X30 Junior and Senior are only
permitted to have club championships until
There is a 'Tour' for X30 in the Little Breen Man series
and qualifying rounds for the international final in the
Super One Series.
Senior4-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
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 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 NKF
and 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
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, contact is Kate Bateman on 01527 871075.