Karting Tyre Rules: Sets, Marking, Parc Fermé and Wet Tyres
Tyre regulations are among the most important parts of a karting rulebook. They control which tyres you may use, how many sets you receive, when those tyres are registered, and what you may do to them during a meeting.
The exact procedure varies by championship, class, country and season. A national junior class may use a different allocation system from a CIK-FIA international event, while a club meeting may have no formal tyre registration at all. Always read the event’s supplementary regulations and tyre bulletin alongside the technical regulations.
The principles below explain how karting tyre rules usually work and what to check before arriving at the circuit.
Which tyres may you use?
In most competitive owner-driver karting, the permitted tyre is defined by the class regulations or event supplementary regulations. The rule normally identifies:
- The approved manufacturer and tyre model
- The compound or hardness option, if more than one is homologated
- The front and rear tyre sizes
- Whether slick and wet tyres are required or optional
- The number of tyres available for practice, qualifying and races
- The date or homologation period for which the tyre is valid
A tyre being the correct size does not make it legal. A different model from the same manufacturer, an older homologation, or a compound intended for another class can all be illegal even if the tyre fits the wheel.
Tyres supplied by an official event tyre supplier are often controlled by barcode, serial number or another identification system. At some meetings, competitors buy or collect their tyres from the supplier and register them before use. At others, the organiser allocates a numbered set directly.
Rental karting is different. The circuit normally supplies and controls the tyres, and the customer does not select, register or retain a set. The rules in this guide mainly apply to owner-driver racing.
What counts as a set?
A dry set normally consists of two front tyres and two rear tyres. Some regulations define a set differently, so check the wording rather than relying on paddock terminology.
The permitted number of sets is usually separated into categories such as:
- Practice tyres
- Qualifying tyres
- Race tyres
- A controlled or sealed race-weekend allocation
- Wet tyres, which may have a separate allowance
A championship may allow one new dry set for a race meeting, while another may allow a set for official practice and a second set for qualifying and racing. Some series allow used tyres from earlier sessions, but only if they have been registered to that driver and remain within the event allocation.
Do not assume that a tyre used in practice can automatically be used in the race. The rule may require the tyre to be registered before practice, may restrict it to a particular session, or may provide a separate race allocation.
Likewise, do not assume that an unused tyre can be carried into the next meeting. Some championships use a fresh allocation at every event; others allow tyres to be retained for a defined period. The technical regulations should state whether the control is per event, per round, or per championship.
When are tyres registered?
Tyre registration is the process of linking a legal tyre to a competitor, kart or event allocation. It may involve scanning a barcode, entering serial numbers on a tyre declaration, presenting the tyres to an official, or collecting them through the event supplier’s system.
The registration deadline is critical. Common deadlines include:
- Before a specified practice session
- Before the first official track session
- Before qualifying
- Before tyres are fitted to the kart
- Before entering parc fermé
These are not interchangeable. If the regulations say that tyres must be registered before official practice, registering them later may make them ineligible even if they were never used.
A practical pre-event checklist is:
- Find the tyre allocation and registration section in the event documents.
- Check whether registration is required for practice, racing, or both.
- Confirm the exact deadline and location of the tyre office or control area.
- Check whether all four tyres must be presented together.
- Record the identification numbers for your own records.
- Ask the scrutineer before fitting a replacement or changing the allocation.
A tyre registered to another driver is generally not yours to use. Sharing tyres between team-mates, changing a driver entry, or moving tyres from one chassis to another may require official approval, even when the tyre itself is legal.
How are tyres marked or identified?
Tyre identification normally uses a barcode, serial number or supplier record. In some championships, officials also apply a physical mark such as paint or a sticker. The purpose is to prevent competitors from introducing an unregistered set or replacing a worn tyre with a new one after registration.
The identification may be checked at several points:
- When tyres are issued or purchased
- During pre-event scrutineering
- Before a session
- At the pit-lane exit
- When the kart enters parc fermé
- During post-race technical inspection
Keep the identification markings legible. Do not remove, damage or deliberately obscure a barcode, serial number, sticker or official paint mark. If a mark becomes unreadable through normal use, report it to an official before the next session rather than trying to recreate it yourself.
Marking a tyre does not usually make an otherwise illegal tyre legal. A tyre with the wrong model, compound or homologation remains illegal even if it has been marked or scanned.
What is parc fermé?
Parc fermé is a controlled area where the kart and, in some championships, its tyres must remain under official supervision. The term literally means closed park, but the practical meaning is a restriction on what the competitor may do after the kart enters that area.
Parc fermé controls vary. At one event, the kart may enter after qualifying and remain there until the race. At another, only the tyres are controlled, or the kart is placed in parc fermé after each race. Officials may also use a designated tyre storage area rather than a traditional fenced enclosure.
Once a kart or tyre is in parc fermé, you may not normally:
- Swap tyres with another set or another driver
- Replace a tyre without permission
- Change the tyre specification or compound
- Carry out unapproved work on the kart
- Remove the kart or tyres from the controlled area
- Alter tyre identification marks
Some regulations allow limited work, such as adjusting tyre pressure or making a repair after an incident. That permission must come from the event officials or be explicitly stated in the regulations. Never assume that a normal setup adjustment is permitted simply because the kart is in your pit area.
If a tyre is damaged in a crash, punctured, loses its bead, or is found to have a manufacturing defect, stop and report it. The usual process is for the technical delegate or chief scrutineer to inspect the tyre and decide whether a replacement is allowed. A replacement may need to be the same type and may be marked or recorded as the substitute.
Changing a damaged tyre without approval can create a tyre infringement even when the original damage was genuine.
Which changes are usually permitted?
The answer must come from the specific regulations, but karting tyre rules commonly distinguish between normal operating adjustments and changes that alter the tyre itself.
Tyre pressure
Adjusting cold or hot pressure is normally part of setup work, but it may be restricted after a kart enters parc fermé or once it reaches the grid. Some events specify where and when pressure may be checked or changed.
Use a reliable gauge and record pressures consistently. A pressure change made outside the permitted area can be treated as an unauthorised modification, even though pressure itself is not a permanent alteration.
Mounting and dismounting
Mounting a legal tyre onto the correct rim is often allowed before the control deadline. After registration or parc fermé, however, dismounting may be prohibited or allowed only under supervision.
Do not move a registered tyre onto another rim unless the rules clearly permit it. The tyre and rim may be inspected together, and some championships control the wheel assemblies as well as the rubber.
Cleaning and removing debris
Removing dirt, rubber pickup and loose debris is generally treated differently from altering the tyre. A clean tyre can still be inspected properly, but the method matters. Scraping, grinding, sanding or cutting the tread is commonly prohibited unless the regulations specifically permit it.
Tyre treatment and chemicals
Applying solvents, softeners, oils, adhesives or other chemicals is prohibited in many championships. These products can change the tyre’s physical properties and may also create a safety risk. The same applies to soaking, heating or storing tyres in a way intended to alter their performance.
Some series conduct chemical or physical tyre testing after a session. A tyre that passes visual inspection can still fail a technical test.
Tyre warmers and artificial heating
Tyre warmers, hot boxes and other artificial heating equipment are prohibited in many karting classes, but not universally. The rule may cover both electric warmers and less obvious methods such as heated storage or hot air.
If warmers are banned, treat the ban as applying to the tyre, wheel and storage process unless the regulations say otherwise. Do not rely on advice from a different class or championship.
Cutting or reshaping
Cutting grooves into a slick, removing tread from a wet tyre, rounding edges, drilling, shaving or otherwise reshaping the tyre is normally prohibited. A wet tyre must remain the approved wet tyre, and a slick must remain the approved slick.
Even where a class allows limited tyre preparation, the permitted tools and amount of material removal should be stated clearly. If the rule is not explicit, ask the scrutineer before doing the work.
Wet tyres and changing weather
Wet tyres are designed for standing water and a wet track. They have a grooved tread pattern that moves water away from the contact patch. Slick tyres are intended for a dry surface and do not become legal wet tyres merely because the track is damp.
The race director normally decides when wet tyres may be used, or whether a session is declared wet. The decision can affect more than tyre choice: it may change whether wet tyres are mandatory, whether tyre warmers are allowed, and whether a kart can be worked on between the grid and pit lane.
Common arrangements include:
- A separate wet-tyre allocation for the meeting
- An unlimited or partially controlled number of wet tyres
- Wet tyres supplied or marked by the official tyre supplier
- A race director declaration before the session
- Free choice between slicks and wets when the track is wet, subject to safety instructions
The number of wet tyres permitted varies considerably. Some championships control wet tyres as tightly as slicks; others permit a larger allowance because weather is unpredictable. Do not assume that rain makes the tyre allocation free of restrictions.
When the track dries, the race direction may permit or require a change back to slicks. The timing and location of the change still matter. A tyre change in the paddock, on the grid or in a designated repair area may be treated differently under the event rules.
Common tyre-rule mistakes
The most frequent problems are procedural rather than related to driving performance:
- Using a tyre from the wrong compound or homologation
- Missing the registration deadline
- Treating a practice set as automatically legal for the race
- Sharing a registered tyre with another driver
- Replacing a damaged tyre without technical approval
- Removing or obscuring an identification mark
- Applying a chemical, tyre softener or unauthorised cleaner
- Using tyre warmers where they are banned
- Cutting a slick or reshaping a wet tyre
- Changing tyres after entering parc fermé without permission
How to manage tyre compliance at a race meeting
Before travelling, download the latest technical regulations, supplementary regulations and tyre bulletin. Highlight the sections covering allocation, registration, marking, parc fermé, wet conditions and replacement procedure.
At the circuit, photograph or record each tyre identification number, check that the marks are readable, and keep tyres separated by driver and session. Bring the required wheels and tools, but do not perform a non-routine tyre change until an official has confirmed the procedure.
The safest rule is simple: if a change affects the tyre’s identity, construction, compound, registration or location in parc fermé, ask before doing it. In karting, an approved tyre used under the wrong procedure can still result in exclusion.