IFMAR to implement 109mm minimum tire diameter rule

With concerns over the interpretation of the rule on minimum tyre diameter rumbling around the pits today from around lunch time, IFMAR has this evening made a clear decision that it will implement the ruling as it stands post race despite the concerns over the high tyre wear being experienced at the 1:8 Offroad World Championship in Spain.  Many leading drivers had expressed concerns as to how the rule would be implemented, confusion appearing to stem from issues at the European Championship where a pre-race inspection was used.  When we were first made aware of the concerns of the ruling an official source told us that almost 50% of cars in qualifying would have been DQ’d had the post run rule been implemented.

It is understood that there was a major push from one tyre manufacturer to have the 109mm minimum diameter ruling implemented post race given the overall larger diameter of its tyres while the rest are at risk of disqualification due to the high wear being experienced at the RC-Redovan track.  While rules are in place for a reason, it appears the timing, right after the conclusion of qualifying, could now over shadow the race given drivers had used the final few qualifiers to gather tyre data for the finals.  For some drivers the ruling could mean having to switch to pin tyre with no previous running on such a set-up.

With the rule sure to affect many of the amateur drivers who have made the trip to Spain, the matter raises the issue of whether or not future World Championships should run a spec tyres.

IFMAR issued the following bulletin on the matter –

IFMAR International Jury meeting 12/09/2024

This meeting has to do with the minimum tire diameter of 109mm.

Rule 2.4c
2.4.c. Wheel/tire overall diameter must be:
Max dia. 120.00 mm / 4.724 inches
Min. dia. 109.00 mm / 4.29 inches
Width 47.00 mm / 1.85 inches

No rim specs
Tire wear here at Redovan is an issue and for the main final we foresee a problem, perhaps already in the earlier finals of 30 minutes, due to the rule above.

After a meeting with the manufacturers followed by a long discussion and a second meeting with the international jury, also with a long discussion the final decision was made to stick to the rules. During the meeting with the tire brands the majority of tire manufacturers told us that preparing a tire for 60 minutes is possible and asked us to stick to the rules.

The tire diameter must be respected , also after the final when cars are checked in technical inspection.

We stick to the rule, meaning 109mm after each race is the minimum for each tire. If smaller you will be disqualified.

For the main final 2 or more sets of tires per driver will be marked and after the final all marked tires must return to technical inspection to be measured.

Sander de Graaf / IC Section Chairman