Summary

As ORCi Stock Rod drivers are aware, the formula will be moving to a new control tyre during 2024 as supplies of the Yokohama AO21R dry up following the ceasing of production. The aim of ORCi Stock Rod promoters is to have a managed transition to whichever new control tyre is agreed upon, while at the same time keeping costs low for drivers, and managing the run-out of existing AO21R tyre stocks so as to minimise wastage. To help guide drivers towards tyre choices for the 2024 season, set out below is a flexible transition plan that can accommodate a change in the final hard cut-over date subject to stocks and supplies of the AO21R. 

By the end of February
More tyre testing will have been undertaken.
This is especially pertinent at Cowdenbeath, where drivers who have helpfully assisted with the test programme to this point are seeking dry track conditions to evaluate the tyres under consideration.

1 March to 30 April
The Yokohama A021R will remain as the only tyre permitted for use on the car.

During April
Drivers will be encouraged to advise on the quantity of Yokohama AO21R tyres still available for use. This information will help guide ORCi Stock Rod promoters on the choice of appropriate soft and hard cut-over dates.

From 1 May onwards
Depending upon the availability of Yokohama AO21R tyres, the following options will be considered and confirmed for implementation from DD-MM-2024.
Option 1 - Yokohama AO21R tyres permitted on all four wheels.
Option 2 - Yokohama AO21R tyres only permitted on the non-driving axle.
In the case of Option 2, the new control tyre will be mandatory for the driving axle, with the decision on which tyre that will be announced well in advance.