How will the new Cadet tyre be chosen?
Following the publication of tender details by the MSA a few weeks ago for the next Cadet tyre, I’ve decided to highlight the most important parts of the selection criteria. The full document is available here.
Tyres must, to the satisfaction of MSA:
I. be of an appropriate size, a maximum of 10×4.0x5 inches for front wheels;
II. be of an appropriate size, a maximum of 11×5.0x5 inches for rear wheels;
III. be at least equivalent to – and no softer than – the current CIK Hard/Prime
IV. be shown through testing to be no less than a nominal 0.5 seconds‐per‐lap slower than the current tyre when run under the same conditions using the same equipment and driver;
V. be tested for durability as detailed in paragraph 3 (Testing Procedure).
Testing Procedure (Paragraph 3)
The tyre testing is undertaken to choose a slick and associated rain tyre for the MSA Formula Cadet class. The appointed independent tester(s) will maintain confidentiality at all times, only reporting to their MSA contact, and will have no connection to any tyre importer/trader/manufacturer entering tyres for testing in respect of this ITT.
b) Class requirements
i. Different classes require different types of tyre. The Formula Cadet class tyres must provide excellent longevity and a grip level appropriate to the low powered (circa 7 bhp) engine so that the kart can slide in cornering and not be ‘on rails’. The associated wet weather tyre should also be reasonably durable in conditions of a drying track, to provide good life, yet give safe performance in the wet.
ii. The kart used for testing will be ballasted to approximately 2kg over the current class weight limit (103kg + 2kg), so a suitable sized driver/kart/engine combination will be used. It is important that the tyres suit the homologated kart design.
c) The tests (for each tyre type entered) shall include but not be limited to the following matters:
i. Lap times will be taken for every lap run to aid the assessment.
ii. Shore test (slicks and wets).
iii. Estimation of tread depth taken (measured by calliper before fitting on slicks, depth measurement on wets).
iv. Slicks are run for two five lap sessions to set the kart up, any adjustments made, tyre surface temperatures and hot pressures taken to choose optimum pressures.
v. Slicks are run for three fifteen lap sessions, reporting consistency etc, or two 20 lap sessions.
vi. Shore, tread depth, circumference (at normal tyre pressure) taken when cool (rim sizes/width used to be noted).
vii. The tyres will then be sent to a CIK approved test facility for a 500km test in accordance with CIK procedure, but at the Formula Cadet class weight.
viii. A minimum wait of three weeks to allow the tyres to ‘cure’ after use from first track test.
ix. Repeat the test (a to f) at the same circuit, for comparative times.
x. Wet weather tyre testing – full wet conditions, and secondly track drying conditions, shore and tread depth after each, laps to suit.
xi. Final report and recommendation, all lap times made available, summary of fastest laps in each session, shore tests, tread depths. Graphical and tabular representation of each tyre performance will be provided to the MSA.
xii. These tests, repeated after a few weeks, must be carried out at a minimum of two circuits with preferably different surface characteristics. They need to be carried out with both the current class tyres and any proposed new tyres.
NB: The on track elements of the testing (including reporting) will be carried out by an external independent party selected by the MSA.
iv. that a minimum stock level of each tyre (slick and wet) as determined by the MSA is readily available to competitors at all times.
v. that a minimum emergency stock level of 100 complete sets of each tyre (slick and wet) is retained in the UK, which will only be called upon for use in an emergency, or force majeure situation as determined by the MSA.
vii. a funding package to promote Formula Cadet Karting in the UK, including but not limited to details of funding for British and National Championship prize funds.
viii. the proposed retail price of the tyres and demonstration of a reduction of current tyre costs is strongly encouraged for the benefit of motor sport participants in the Formula Cadet class. Wet tyres should have a retail price (rrp) of no more than 10% greater than that for slicks + VAT. There will be an annual review of the price, in consultation with the MSA, with an allowance for any cpi increase.