Kart Tyre Buying Guide 2026

Kart Tyre Buying Guide 2026

By IC Kartstore · Reviewed by Andrew Platt · Last reviewed: 31 July 2026

Quick answer: Racing a UK championship? Buy the exact dry and wet tyres named in your class's Motorsport UK Karting Yearbook 2026 article, then check the championship regs for any tighter allocation or a wet-tyre substitution. Practising or running outside a control-tyre class? Match the tyre size and dry-or-wet spec to your kart. If in doubt, tell us your class, championship, current tyre markings and a photo — we'll confirm.

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In this guide

Two routes to the right tyre

IC Kartstore karts racing on dry slicks
First decide whether you are in regulated racing or practice / unrestricted use

Route A — Regulated racing

If you're entered in a Motorsport UK-permitted championship (Super One, British Kart Championships, NKC, ABKC, LGM, Kartmasters, Trent Valley Kart Club rounds, or an FIA / IAME / Rotax international series) the tyre is chosen for you. Your class's article in the Motorsport UK Karting Yearbook 2026 Edition 1.1 names the exact model. The championship regulations then either mirror the Yearbook or tighten it — NKC 2026, for example, specifies Komet K1W for X30 wets rather than the Yearbook's K3W (NKC regulations).

Buy the class-named tyre, plus wets if the series allocates them.

Route B — Practice or unrestricted use

Practising in a control-tyre class? The same class-named tyre is almost always the right buy — it's what your kart will run at scrutineering, and comparable practice-only compounds don't exist for most UK control tyres. The exception is rental / arrive-and-drive endurance karting, where harder-compound tyres (e.g. from Mitas) exist specifically for durability. If you're between championships, tell us your kart, engine and event plan and we'll spec both a dry set and a wet set.

2026 UK class-to-tyre matrix

The following is taken directly from the Motorsport UK Karting Yearbook 2026 Edition 1.1 National Tyre List. Championship regulations may name a different wet — always check both.

Class Dry tyre Wet tyre
MightE Bambino Le Cont MSA 04 (all-weather) Le Cont MSA 04
Honda Cadet, Rotax Micro Cadet, Rotax E10 Cadet, MightE Cadet Vega Cadetti 'UK' Vega WM1 CIK
IAME Water Swift Restricted (Cadet) Vega Cadetti 'UK' Vega WM1 CIK
IAME Water Swift (Inter) Komet K1D-M Komet K1D-W
Rotax Mini Max Mojo C2 CIK Mini Mojo CW CIK Mini
IAME X30 Junior Komet K3H (rounded-corner barcode, prefix "K") Komet K3W
Rotax Junior Max Mojo D2XX CIK Option Mojo W5 CIK Rain
IAME X30 Senior Komet K3M Komet K3W
Rotax Senior Max, DD2 Mojo D5 CIK Prime Mojo W5 CIK Rain
Formula TKM Extreme Maxxis "TKM" (laser-marked, white label) Maxxis "TKM" (moulded, red label, white outline)
Tillotson T4 Junior & Senior Maxxis T4 (T-MAX-DRY3) Maxxis T4 (T-MAX-WET1)
KZ2 Le Cont LPM (white UK sticker) Le Cont LWR (white UK sticker)
Superkart 250 Championship-nominated, current CIK-FIA homologation as above

UK national commitments to be aware of (Karting Yearbook 2026 Ed.1.1):

  • All Cadet classes (Vega Cadetti UK / Vega WM1 CIK): sole tyres until at least 28.02.2028
  • KZ2 (Le Cont LPM / LWR): sole tyres until at least 31.12.2026 — the UK commitment ends at the close of this season
  • IAME Water Swift Restricted, X30 Junior/Senior (Komet): sole tyres until at least 31.12.2027
  • Rotax classes (Mojo): sole tyres until at least 31.12.2028
  • MightE Bambino (Le Cont MSA 04): Yearbook text states 31.12.2025 — treat as an un-updated date and check the current MightE regulations before buying

Championship allocation caps — how many sets to budget for

The number of tyre sets you can use per round or per season is set by the championship, not the Yearbook. The 2026 figures:

Series Dry allocation Wet allocation Source
Super One (Rotax except Micro) 1 new set per weekend 2 new sets per weekend Super One 2026 Issue 2
Super One Micro Roughly 1 new set per 2 rounds Per event notice as above
NKC 2026 Max 3 new dry sets across a 6-round season Per event NKC regulations
Kartmasters 1 new dry set per event (mandatory) Per event notice Kartmasters 2026 (TVKC)
BKC IAME / Rotax 2026 Per event bulletin Per event BKC IAME / BKC Rotax

Buy for the whole season if you're in NKC; buy per weekend if you're in Super One. Wets are consumables — one set of new wets can be all that separates a full-points weekend from a DNF.

Wet tyres — what actually counts as one

Wet-weather kart racing with grooved wet tyres
When the track is wet, buy the wet tyre named in your rules — or the wet size that fits your practice plan

NCR 2026 Ed.4 Ch.18 App.8 Article 6.6:

"To qualify as a wet tyre tyres must be moulded in such a way as to ensure that grooves are created to leave a minimum of 60% and a maximum of 85% of the total surface area as a raised tread pattern. The grooves must have a minimum depth of 2 mm at race start."

Hand-cut grooves on a slick do not turn it into a wet — Art.6.7 explicitly bans hand cutting. Retreads, remoulds and recut tyres are banned by Art.6.8.

Dry, Open, Wet — what the Clerk of the Course declares

Shop kart tyres at IC Kartstore
Shop what you need — or ask us to identify the right set

NCR 2026 Ed.4 Ch.18 Appendix 5 Article 1.6–1.7:

  • Dry race — slicks only
  • Wet race — wets only
  • Open race — competitor's choice within the class tyres

The Clerk's declaration is what fixes the choice. Your class tyre list from the Yearbook still applies inside that declaration.

The tyre-softener rule — how scrutineers enforce it

NCR 2026 Ed.4 Ch.18 App.8 Article 6.9:

"Heating of tyres by any method or their treatment by any chemical substance is prohibited."

Enforcement uses a photo-ionization detector (PID) held within 5 mm of the tyre surface. The Karting Yearbook 2026 Ed.1.1 Appendix 5 sets the threshold: > 2 ppm within 5 mm of the tyre, and at least 50% higher than the average reading across other competitors' tyres is evidence of chemical treatment.

Championship thresholds differ:

  • NKC 2026: "tyre sniffer" plus durometer readings
  • Rotax Max Challenge (Global): recommends 4 ppm
  • IAME international series: 4–5 ppm

Two things regularly trip clean tyres:

  1. Chain-lube overspray onto tyre sidewall. Mask or shield when lubing.
  2. Storage next to a fuel container or open solvent. Store tyres in a clean, dry, sealed area.

Pressure guidance — PSI, with source

Every manufacturer publishes cold or hot service pressures in bar; we've converted to PSI for UK paddock use. Bar figures in brackets are the manufacturer's original number so you can cross-check the technical card.

Tyre Recommended pressure State Source
Vega Cadetti 14.5 PSI (1.00 bar) ± 2–3 PSI Cold, indicative Vega Cadetti data sheet
Vega XM4 CIK Prime / XH4 CIK Option 8.0 PSI (0.55 bar) front and rear ± 3 PSI Cold Vega spec sheet
Komet K3M / K3H (X30 senior/junior dry) 11.6 PSI (0.80 bar) ± 4 PSI Service (at 23 °C) Komet K3M technical card
Mojo D5 (Rotax Senior/DD2 Prime) 8.0–8.7 PSI (0.55–0.60 bar) ± 0.7 PSI Cold Rotax MOJO D5 / D5 Technical Card
Mojo D2 / D2XX (Rotax Junior Option) 8.0–8.7 PSI (0.55–0.60 bar) Cold Rotax technical card
Mojo W5 CIK Rain 15.9–16.7 PSI (1.10–1.15 bar) starting Cold, indicative Rotax technical card
Le Cont, Maxxis TKM/T4 Not published on manufacturer sites — Ask us for paddock-verified starting figures

Cold vs hot matters. Vega and Mojo publish cold. Komet K3M is a service pressure at 23 °C ± 2 °C, 50% ± 5% humidity — treat it as a starting reference, not a hot target. A rule of thumb: kart tyres gain 2.9 PSI (0.20 bar) over one heat cycle in dry conditions.

Maximum inflation for a Mojo D5 is 58 PSI (4.0 bar) — that's the storage/mounting maximum, not a running pressure. Mojo cautions against storage below 0 °C (current Rotax FAQ); the 2019 technical card figure was −15 °C.

Send us the class, event and last-run pressure and we'll suggest a starting figure specific to the circuit.

Kart tyre sizes — how the markings work

Kart tyres are measured in inches, and two size formats appear side by side on the FIA 2024–2026 tyre technical list:

  • Overall diameter × section width – rim diameter — e.g. "10 × 4.60-5" means 10 in overall, 4.60 in wide, on a 5 in rim
  • Section width / overall diameter – rim diameter — e.g. "4.5/10.0-5" is the same tyre, expressed differently

Simple rule: the rim number is always last, and the larger of the other two numbers is always the overall diameter.

The two dominant UK racing sizes:

  • Senior/Junior: 11 × 7.10-5 rear, 10 × 4.60-5 (or 10 × 4.50-5) front
  • Cadet: 11 × 5.00-5 rear, 10 × 4.00-5 front

Bead coupling to a standard 5 in kart rim is 126.2 mm (+0 / −1 mm), minimum housing width 10 mm (IAME Series 2025/2026 technical regs).

Homologation cycle — plan for 2027

The tyres currently in force through the 2026 UK and FIA seasons come from the FIA 2024–2026 homologation cycle (FIA Technical List — Tyres 2024–2026). The next cycle is 2027–2029, with applications on form H1_PNEU_2027-2029 due by 1 August of the current year (FIA 2026 Karting Homologation Regulations V2.1).

What this means for a buyer in the second half of 2026:

  • Tyres bought for FIA-category use may be superseded from 1 January 2027, subject to a three-year grace on obsolete homologations for existing stock
  • The UK Yearbook commitments in the class matrix above override the FIA cycle for the classes they cover (Cadet, KZ2, X30, Rotax national)
  • KZ2 UK tyre commitment ends 31.12.2026 and will be re-tendered
  • Inflate with air or nitrogen only — NCR Art.6.12 prohibits any other gas
  • Remove mechanical debris only — Art.6.11 prohibits any chemical cleaning of tyre surfaces
  • Store cool, dry, sealed — direct sun and ozone (UV lamps, running motors) age rubber
  • Do not stack on hubs long-term — flat-spots and bead-seat deformation
  • Log pressures — same tyre, same circuit, same weather is the fastest way to build a reliable pressure map

Ready to order?

Tell us your class, championship, kart, engine and event plan and we'll spec the exact dry set, wet set and starting pressures. If you're on a UK sunset (KZ2 for 2026, Cadet through 28.02.2028) we'll flag it so you don't over-commit to soon-to-obsolete stock.

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Need help choosing?

Send us your class, event and the specifics from this guide's checklist. We'll shortlist two or three options from what we stock, flag any homologation or fitment risk before you commit, and answer follow-up questions before you order.

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Sources cited in this guide

Byline: IC Kartstore · Last reviewed 31 July 2026

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