Regs
2025 Technical Regulations
A1. Introduction: - GX-UK Cadet class is a race series built around the Honda GX160 engine and a wide variety of otherwise, underutilised chassis’ in order to create a low-cost way to enter owner karting.
The class ethos is to allow all competitors to race competitively with longer life 4 stroke engines, stable class regulations and on a minimal budget.
Whilst the spirit of competitive racing is being embraced, certain concessions to more broadly used regulations have been implemented with the sole aim of reducing costs, whilst also opening up the class to as many competitors as possible.
The Series Organisers reserve the right to amend the regulations based on safety at short notice.
Minor clarifications to the regulations can be made with 4 weeks’ notice from affect and will be
published on the GX-UK Facebook Page and the Access Karting website (www.accesskarting-uk.com).
Any major rule changes such as, tyres, significant weight limit and chassis will only be done in
between a championship finishing and the next commencing unless subject to force majeure.
The GX-UK classes runs within the sporting regulations utilised by 100-UK or an IKR host. This will be made clear before each meeting.
In any scenarios when the GX-UK regulations are, or could be viewed as ambiguous the MSUK Honda cadet engine fische shall override.
A2. Engine
A2.1 All engines are to meet be sold from standard or to the RPM MSUK spec fiche less the restrictor. However, replacement Honda manufactured are permitted only. Front Sprocket sizes open and does NOT have to be a Honda original part.
A2.2 all engines are to run a clutched with a pull cord starting mechanism.
A2.7 engines are to be of the original stamped cc volume of 160cc.
A2.8 fuel tanks can be mounted on top of the engine as sold as standard or removed and placed around the steering column in the more conventional karting layout.
A2.11 Maximum of 2 engines per entrant to be signed on per race day.
A2.12 External repainting of barrel and head allow for aesthetics – outside only.
A2.13 Engine mount may be aluminium, steel or magnesium
A3. Airfilter and box
A3.1. Airboxes and filters must conform to the standard shape and position as they are when sold and cannot be modified.
A3.3a. No drilling of the airbox or filter is permitted apart from the fitting of an overflow bottle bracket.
A3.4b Air Filter must be intact with all the relevant elements present as per the MSUK Honda Cadet fische
A4. Carburettors
A4.1 The only permitted carburettor is the standard Honda carburettor as supplied as standard.
A5 Exhaust
A5.1 All 3 different configurations of the GX160 exhausts are permitted. These are identified as the original black square box exhaust as sold when standard, the oval exhaust and the circular exhaust as sold by RPM.
A5.2 If a heat shield bracket is present on the chosen exhaust from 5.1, a heat shield must be run for safety. These brackets cannot be removed if present from new.
A6 Chassis
A6.1 Permitted Chassis
1) Any 900mm wheel base Cadet up to and including 2018 provided they meet the criteria listed below, however, it is advisable to seek chassis acceptance prior to attempting to race with it.
a) 2 Bearing
b) Adjustable rear ride height is permitted.
A6.2 Seat stays are not permitted.
A6.3 25mm axles only permitted. Hollow or solid axles are permitted
A6.4 Extended rear hubs are permitted, hubs may over hang the rear axle providing that they are of
a 2 bolt design as a minimum of 2 fixing points must be present for safety.
A6.6 Akerman or single fixing point columns can be used.
A6.7 Stub axles are open but must be 17mm or smaller and front hubs are prohibited
A7 Chainguards/Fingerguards
A7.1 Fully enclosed chain guard must be fitted to enclose front engine sprocket and rear sprocket.
This can be modified to fit provided the chain remains enclosed.
A8 Brakes
A8.1 Brakes can be hydraulic, or cable operated
A8.2 Calliper and Master Cylinder are free, except for
1) Brake disc must be steel, solid or vented, cross drilled, floating is permitted
2) No ABS
3) Maximum of 1 pad per side and 2 pistons per pad.
4) Self-adjusting systems are allowed
A8.3 Brakes must operate on the rear wheels only.
A8.4 Secondary (back-up) brake cable is required between pedal and master cylinder.
A9 Wheels and Tyres
A9.1 Aluminium or Magnesium wheels are permitted but must be of one piece moulding
A9.2 Front wheels are to be bearing types.
A9.3 Stub axles are open provided they don’t house a front braking system
A9.4 Rims are open for the class.
A9.5 Tyres are to be the Dunlop SL3 cadet Slick and the Dunlop KT3 wet.
A9.5a slicks are limited to 2 new sets per season. Wets are limited to 1 set per round.
A9.5b tyres may only be replaced or changed on safety grounds after inspection and agreement
A9.5c Treatment of tyres is not permitted, not chemicals can be added to the tyres and durometer
tests will be carried out against the base mark of the tyre
A9.6d Wets must be nominated at the start of a meeting, minimum thread depth for a wet to be allowed on track is 1mm when presented on rims for measuring with at least 15 psi mounted on rims.
A10 Maximum Width/Track
A10.1 Maximum front track, measured from outer most points of front tyres/wheels – 1050mm
A10.2 Maximum rear track, measured from outer most points of rear tyres/wheels – 1200mm
A11 Exotic materials
A11.1 Magnesium is allowed except for where specified within the regulations
A11.2 Carbon Fibre/Carbon composites are allowed except where specified in the regulations
A11.3 Titanium is allowed except for where specified within the regulations
A11.4 No other form of exotic material are permitted including but not limited to titanium etc
A12 Bodywork
A12.1 Chassis must run side pods and front bumper/nose cone – style Unico crash tested or newer
A12.2 Competitors must run all sponsors and GX-UK stickers supplier on either their nassua panel, side pods, engine cover or helmet.
A13 Minimum Weights
GX-UK Junior – Unrestricted GX160 – 105kg
A14 Number Plates/Board
A14.1 Cadet;- Race numbers are to be Orange on a yellow background. Numbers to be displayed front, rear and sides.
A15 Rear Bumpers
A15.1 Full length rear bumper covering at least 50% of the rear tyres. The rear bumper CANNOT
protrude beyond the outer edge of the rear wheels.
A15.2 plastic or metal style bumpers are accepted.
A16 Rev Counters / Data Loggers
A16.1 Rev Counters and GPS systems are allowed such as the Mychron and Alfano
A17 Steering Wheels
A17.1 Steering wheels are open fitting type, 3 and 6 bolt are allowed
A17.2 Flat top or/and bottom permitted
A17.3 3 spoke shaped fitment area for data logger wheels are allowed
A18 Age ranges
A18.1 A cadet must be 8 years of age on the date of competing.
A18.2 A cadet can remain in the class in the year they turn 12, once they turn 12 they may complete the calendar year as a Cadet before they must compete as a Junior.
A18.2 Once a competitor has taken part in a Junior race within Access Karting, they cannot revert to being in the Cadet under any circumstances.