Find out all about the features of the typical go kart and how simple but thrilling they are to drive!
The chassis are made of chrome moly tubing. There is no suspension so chassis have to be flexible enough to work as a suspension and stiff enough not to break or give way on a turn. Kart chassis are classified in the United States as ‘Open’, ‘Caged’, ‘Straight’ or ‘Offset’.
- Open karts have no roll cage.
- Caged karts have a roll cage surrounding the driver; they are mostly used on dirt tracks.
- In Straight chassis the driver sits in the center. Straight chassis are used for sprint racing.
- In Offset chassis the driver sits on the left side. Offset chassis are used for left-turn-only speedway racing.
The stiffness of the chassis enables different handling characteristics for different circumstances. Typically, for dry conditions a stiffer chassis is preferable, while in wet or other poor traction conditions, a more flexible chassis may work better. Temperature of the track can also affect handling and may prompt additional chassis adjustments. The best chassis allow for stiffening bars at the rear, front and side to be added or removed according to race conditions.
Braking is achieved by a disc brake mounted on the rear axle. Front disc brakes are used in most shifter kart classes and are increasingly popular in other classes; however, certain classes do not allow them. Shifter karts have dual master cylinders, one for the front and one for the rear and are adjustable to allow for front/rear bias changes.
Professionally raced karts typically weigh 165 – 175 lbs. without driver.
Amusement park go-karts can be powered by four-stroke engines or electric motors, while racing karts use small two-stroke or four-stroke engines.
- Four-stroke engines can be standard air-cooled industrial based engines, sometimes with small modifications, developing from about 5 to 20 hp. They are adequate for racing and fun kart applications. There are also more powerful four-stroke engines available offering from 15 hp up to 48 hp. They run to and around 11,000 rpm, and are manufactured specifically for karting. Those are used in some National Championship classes like the two-strokes.
- Two-stroke kart engines are developed and built by dedicated manufacturers. These can develop from about 8 hp for a single-cylinder 60cc unit (MiniROK by Vortex) to over 90hp for a twin 250 cc. Today, the most popular categories worldwide are those using the TaG 125 cc units. The recent 125 cc KF1 engines are electronically limited at 16,000 rpm. Most are water-cooled today; however, previously air-cooled engines dominated the sport.
Purpose of transmission: There are three reasons for having a transmission in the automotive power train or drive train. The transmission can:
- Provide torque needed to move the vehicle under a velocity of road and load condition. It does this by changing the gear ratio between the engine and crankshaft and vehicle drive wheel.
- Be shifted into reverse so the vehicle can move backward.
- Be shifted into neutral for starting the engine and running it without turning the drive wheels.
Karts do not have a differential. The lack of a differential means that one rear tire must slide while cornering. This is achieved by designing the chassis so that the inside rear tire lifts up slightly when the kart turns the corner. This allows the tire to lose some of its grip and slide or lift off the ground completely.
Power is transmitted from the engine to the rear axle by a chain. Both engine and axle sprockets are removable. Their ratio must be adapted to the track configuration to obtain the most performance from the engine.
In the early days, karts were direct drive (requiring push starts). The inconvenience of that configuration led to the centrifugal clutch for the club level classes. Dry centrifugal clutches are now used in many categories (Rotax Max is one example) and have become the norm as the top international classes have switched to 125cc clutched engines as of January 2007.
Wheels and tires are much smaller than those used on a normal car. Rims are made of magnesium alloy, aluminum, or composite materials. Some car tire manufacturers, such as Bridgestone, Dunlop, and Maxxis make tires for karts. There are also specific kart tire manufacturers, which include MG, MOJO, Vega, Hoosier and Burris.
Similar to other motorsports, kart tires have different types for use appropriate to track conditions:
- Slicks, for dry track. Slick kart tires come in many different compounds, from very soft (maximum grip) to very hard (amusement and rental karts, less grip but long life span). In international level racing, because the drivers are free to choose their tires and because of the short duration of each round (10 to 20 minutes maximum), these are some of the softest tires found in motorsport.
- Rain tires, or “wets”, for wet weather. They are grooved, made of soft compound, and are narrower than slicks. Not all racing classes allow rain tires.
- Special, such as spiked tires for icy conditions, or “cuts/grooved” for high grip dirt/clay speedways. Cuts are slicks modified with a lathe to optimize handling. Tire manufacturers such as Hoosier and Burris also make a slightly larger grooved tire only used in dirt track racing.
As in other motor sports, several data acquisition systems have been developed for kart racing. These systems allow the driver to monitor from a display fixed on the steering wheel some parameters such as RPM, timing of laps (including sectors), number of laps, best lap, cooling system temperature, exhaust gas temperature and sometimes speed or even gear for shifter karts.
Some of those systems are able to record (logging) laps data from the sensors, allowing replay of an entire running session or/and direct download to a personal computer equipped with a data analysis software. More sophisticated systems allow for more information such as lateral and longitudinal acceleration (g-force), throttle position, steering wheel position and brake pressure.
The all-important control center of the go kart, the steering wheel tells your rear wheels which way to go. Along with every other vital component of the kart, the steering column is regularly tested by our trackside team to make sure it’s responsive and fit for high-speed thrills.
The heavy-duty plastic or fiberglass seating is fully adjustable, so whether you’re tall or small, you’ll be able to reach the pedals without a hitch.
Along with the steering, these are the bits you need to master if you want to know how to drive a go-kart! There are no gears to worry about on a standard kart, just an accelerator pedal that pumps juice into the engine and a brake pedal that helps you control your speed. Many karts are fitted with anti-double pedaling tech, which stops you accelerating and braking at the same time and protects the clutch from damage.
The bumpers at the front and rear are important safety features. Made of heavy-duty plastic, they surround the kart to absorb the worst of the shock on any impact. So even if you do lose control and go into the tires, you won’t be out of the race for long!