Karting Divisions and Classes
In the zone...
When driver and kart become one
What all classes of karts have in common is that the vehicles are relatively straight forward, in order to keep cost low.
Karts do not use any suspension, and the rear axle is stiff, meaning it has no differential and results in both
rear wheels always turning at the same rate at all times. The driver is not restrained by any seat belts (except
in some classes of karting, for example the cage karts). The engine(s) is/are typically mounted next
to the driver. The power is transmitted by a chain, and a centrifugal clutch may or may not be used. Some classes,
so called shifters, actually utilize a sequential gear-box.
There is a confusingly large number of different types of karting and karting classes to choose from, and this
alone is probably the most bewildering aspect of karting for many beginners. There are several distinct divisions
(types) of karting, and within each type there is a multitude of classes.
So, let us start the overview by discussing the divisions of karting.
1. KARTING DIVISIONS: SPRINT, ROAD-RACE, SPEEDWAY AND SHIFTER
Sprint karts are typically raced on shorter, dedicated kart tracks, called sprint tracks. Sprint tracks resemble small road
courses, with left and right turns, widely varying in length from about 400 meters (1/4 mile) to about 1.5
kilometers (7/8 mile). This type of karting is probably the most common division of karting around the world.
Most of the current F1 drivers have started in sprint kart racing. The twisty courses require the drivers to have
mastered good cornering techniques to be fast. The racing is often wheel-to-wheel, making for a very exciting
venue. Besides qualifying, the format of which may differ from organizer to organizer, there are usually pre-races
and a final race, ranging anywhere from 10 to 25 laps in length.
A sprint kart in international competition
Speedway racing takes place on small dirt or asphalt ovals, ranging in length from less than 200 meters (1/10 mile)
to up to 400 meters (1/4 mile) in length. Purpose built karts are used, with special features to facilitate this
left-turn only racing. For example, oval karts are typically 'offset', meaning that the rear of the kart is not
exactly aligned behind the front, so the karts look decidedly asymmetric. The outside rear tire tends to be bigger
than the inside rear as well. Passing, drafting and smooth driving skills, maintaining maximum RPM, are important
for speedway racing. Since speedway tracks are cheaper to build than sprint tracks, they may far outnumber other
forms of kart tracks in some parts of the country. Thus, travel to the event may be cheaper, which combined with typically
smaller entry fees, makes for an interesting and even lower-cost alternative.
A speedway kart
The kart is asymmetric: Note how close the driver sits to the left rear
Road-racing karts, sometimes also called 'Enduro' karts, are typically raced on the bigger race tracks, like those
which are used by CART, NASCAR of F1. A variety of the enduro karts is the lay-down enduro, in which the driver is
laying flat. The whole kart is longer and slimmer looking than sprint karts. There is also the situp-enduro
racing, where an ordinary sprint kart is used to race on larger tracks, usually with a few modifications like larger
tanks and different gear ratios. The longer straights on the larger tracks allows for higher speeds, and thus this
kind of karting is typically recommended for somewhat more experienced drivers. Drafting and race strategy are important.
Events often last more than a day, and require traveling to the various race tracks, which may be further apart. That
makes this form of karting somewhat more expensive than sprint racing.
A lay-down or 'enduro' kart
Raced on long tracks, minimizing drag is important
Shifter karts utilize a sequential gear-box, which allows the driver to operate the engine in the optimum RPM ranges.
Thus, shifter karts tend to be significantly faster than non-shifter karts with otherwise similar engines (as measured
in displacement or horse power), and are therefore recommended for experienced drivers. Shifter karts typically are
raced on sprint tracks, and therefore require extremely fast reflexes: The driver not only has to focus on the
cornering, on passing and defending the track position, but also on changing gears at the right shift points. A shifter-kart
driver is very busy, indeed. The higher mechanical complexity of the shifter kart, which includes not only the gear shifter
and gear box, but in some cases also front brakes, contributes to the higher up-front cost for this type of kart. But
shifters are often preferred by professional racers, which already made it to CART or even F1, since they can practice
on them in the off-season to keep their reflexes sharp. Shifter karts tend to run as their own division, even though they
are also raced on sprint courses as well as road-courses. Clubs will often run non-shifter and shifter karts during the
same race weekend.
A shifter kart
Note the shift lever on the steering column
2. MORE DIFFERENTIATIONS: CLUTCH OR DIRECT DRIVE?
As we have seen in the overview of the karting divisions, there are many kinds of karts, which do not utilize a gear
box. These non-shifter karts come again in two varieties: Direct drive, where the engine drives the rear axle through
a chain directly, and clutch (centrifugal clutch, to be exact). In case of a centrifugal clutch, the chain drives the
rear axle only once the engine has reached a certain RPM, called the stall speed. Direct drive is popular all over the
world, while in the US most classes are utilizing the centrifugal clutch. Direct drive karts need to be push-started,
which can look quite acrobatic if done by the driver. Clutch-karts, on the other hand, can actually idle the engine
while at a stand-still, but require a separate starter to fire up the engine.
Push start for a direct drive kart
3. ENGINE TYPES: 2-CYCLE OR 4-CYCLE?
As you can imagine, the differentiations continue. You can now choose either to run in a 4-cycle class, or in a 2-cycle
class. 2-cycle engines have been the most dominant and widely used karting engines around the world for decades. They
provide a great power to weight ratio, are mechanically simple, and therefore ideal for the karting application. Most
serious international competition takes place with 2-cycle engines, either air-cooled and increasingly also water-cooled.
Most shifter-karts typically are powered by 2-cycle engines.
A popular 2-cycle engine
Typically, the 2-cycle engines have just one cylinder and range in size from 100cc to 125 cc. Some of the 2-cycle engines
used in karting can reach around 19,000 RPMs, produce up to 40 horse powers, and have a fantastic power to weight ratio.
Some classes utilize even larger engines, with up to 250 cc displacement.
4-cycle racing is particularly popular in some parts of the U.S. However, even in that country, the 2-cycles still outnumber the
4-cycle karts. One of the advantages of 4-cycle engines is that no messy oil-gasoline mixing needs to be performed. The
engines also tend to run somewhat more quietly and tend to last longer. In some 4-cycle classes, Methanol is used, instead
of ordinary gasoline.
Briggs & Stratton Raptor
Example of a 4-cycle engine
Lately, 2-cycle engines have come increasingly under pressure for environmental reasons. The fact that the engine is
lubricated via oil in the fuel, which then gets spit out through the exhaust, is really not very environmentally friendly.
Therefore, even the largest international karting sanctioning body, the CIK (see the article about
Karting sanctioning bodies), has begun to push for the removal of 2-cycle
karting engines out of their competitions over the next few years. However, for the time being, 2-cycle racing is
still alive and well.
4. KARTING CLASSES: SOME EXAMPLES
Within each division or type of karting there are many different classes. These classes are specifically designed to
cater to drivers of different age, skill and even weight levels. In addition, the classes may also be specialized for
different types and makes of engine. Here are some examples of those classes.
Every club will have an often sizeable set of classes that it runs on a weekend. It is not uncommon to find that
about a dozen classes are run during a race event by a single club. There are likely to be various 4-cycle classes,
divided into different age or weight groups. Then there are the venerable Sportsman classes, which typically are based
on the Yamaha KT-100 2-cycle engine, and which comes with different more or less restrictive exhaust systems, as well
as different age and weight classes. These engines, 2-cycle and 4-cycle, are probably the cheapest entry into the world
of karting. Please note that these examples are mostly applicable to racing in the U.S. However, similar situations may
be found in clubs around the world, even though different names may be used, or certain classes may be more popular than
others, compared to the U.S.
Driver's meeting at the start of the race day.
Clubs often have many competitors in a wide variety of classes
Lately, a new concept has entered karting, which some people refer to as 'TaG' (Touch and Go). These are engine packages
that include an integrated push-button starter, thus eliminating the need for an external starter, or acrobatic push-starts.
The first engine popularizing this concept was the Rotax Max from Bombardier-Rotax, an Austrian company. This racing series
was well marketed, and is run in many countries around the world. The motors are said to last a long time between rebuilds,
and the engines and exhaust systems are spec. This means that they are not allowed to be modified, thus permitting the racer to
focus solely on his/her own driving and chassis tuning skills.
In addition, Rotax organizes national series' in each country and tops it of with the annual World Final, a
world-championship of sorts for the serious amateur. The concept is very successful, and has prompted other engine
manufacturers to also develop some very good TaG engine packages. So far none of them has also organized a complete
race series around it, even though first movements in this direction are made. TaG engine packages are priced somewhat
higher, but promise lower cost of ownership. This is due the fact that they supposedly need to be 'rebuild'
less often by a professional engine builder in order to stay competitive. They also are much easier to use when alone at
the track, when nobody else is around to start the engine or give a push. On the downside, for the sealed engine types,
such as the Rotax, even a mechanically skilled racer is not allowed to perform any work on the engine him or herself.
This eliminates the ability to learn those skills, or safe money by doing engine maintenance themselves. Ken
Johnson has developed an excellent introduction to Rotax racing in the form of an electronic book, called the
Rotax iDoc (Macromedia Flash Plugin required).
Rotax Max 125 cc 2-cycle engine
The starter-button is clearly visible
Shifter karts are mechanically more complex and therefore tend to be even more expensive than the TaG classes. The common
classes for shifters are 80cc and 125cc, utilizing different engine makes. They often also utilize softer tires, allowing
faster cornering, but therefore also requiring a higher budget for tires.
On an international level, the classes are the ICC (Intercontinental C) for shifters and ICA (Intercontinental A) for direct
drive karts. While these karts are raced on a club-level as well, they may also be raced in national, continental and even
world-championships. The top-of-the-line, the 'Formula 1' of kart racing, is the Formula-A, or just F-A. This class
utilizes high-powered 2-cycle engines in direct-drive mode, which can be very temperamental but also very powerful, capable
of generating more than 40 horse-powers.
Kart race during the race weekend for the Fromula-1 Grand Prix in Monaco
Competition at the international level is very serious, and the amounts of money spent to participate successfully at such
levels is equally astonishing. Engines need to be rebuild frequently, and the best of them can only be rented from the engine
builder, sometimes for more than $1,000 per weekend. Unless you happen to be rich, you need serious sponsor backing.
Just consider costs of some $100,000 to compete seriously for one season in the European championships.
Fortunately, a great first step into karting is the friendly atmosphere of club racing, with much lower budget requirements.
A good used kart, including spares and tools, can be had for some $1500 to $5000. Add another $500 to $2000 for the annual
budget (club fees, race registrations some spares and a new set of tires or two) and you are on your way. Different manufacturers
also offer new kart chassis' for specific classes at good prices. Just because you start with a smaller budget does not mean
that you have to be less serious about your racing. Quite the opposite: No other form of motor sport gets you more bang for
the buck, more of the all-important seat time and therefore more experience than karting at this beginner level! Club racing,
being surrounded by friendly and helpful like-minded fellow racers is also great fun, just to top it of.
5. CHOOSING A DIVISION AND CLASS
Which type and class of karting is right for you? The advise is simple: Go to a track, see what you like and what many
others are participating in, and you probably have found the right type and class of karting for you. You don't want to
be the only one racing in a class. You will learn most if you race a class where you can measure yourself against many
other drivers. Also, when racing what is popular in your region, you will always have people to help you, as well as
good used equipment and supporting shops available to you.
In the pits
Working on the karts during a club race
If you have a chance, visit different tracks, take a look at sprint, road and oval racing. Talk to the folks at the track
and ask questions. They probably will gladly answer you. Karters tend to be a helpful bunch. Also, use the forums on the
Ekartingnews.com web-site. People there are always happy to help a beginner.
If you have a choice between oval racing, sprint and road-racing, it is really up to you which you prefer. You will have
fun and you will learn a lot in all those types of karts.
Shifter karts are more expensive up-front, even though some are saying they may be cheaper in the long run. Since they
are so fast, however, you might want to consider them to be for the more experienced drivers. Also, many describe shifters
as 'a handful' to operate. Not only do you need to concentrate on driving the line, passing, preventing being passed,
etc., but also on the rapid gear shifts. Therefore, shifters are usually not recommended for the beginners.
An interesting point to consider: If you want to learn to become a good driver, then a slow class, such as a small
4-cycle or restricted 2-cycle like the Yamaha KT-100 Sportsman, may be a good choice. Why? Because having an engine with
low horse power will punish you more severely for driving mistakes! To be fast in these classes, you need to be smooth.
If you start out with a strong engine, you may use horse power to cover up your driving mistakes, thus preventing you
from ever actually learning to drive smoothly. You will maybe be 'ok' in your class, but never great. However, if you
do not drive smoothly with a low-powered engine, you will loose significant amounts of time. This forces you very quickly
to learn the smooth driving which leads to success. Once you are winning on a regular basis in the lower powered classes,
you can always move up, where you will continue to benefit from your smooth driving skills.
The thrill of making the podium
If you are really successful, you can move up to the classes used in international competition. But when you have made it
that far, you will not be reading the New to Karting section of the Ekartingnews.com web-site anymore.