Tyres not on list

[Charles Moles]

Hi,

I will be joining the Edinburgh event for my first event. Do the tyres have to be on the approved tyre list or can we have any tyre provided the lateral block gaps are no more than 8mm.

thanks

[Mike Tucker]

What size rubber are you looking at buying? - we might be able to point you at the best tyre choice

[Paul Wheatley]

The tyres must be on the list but you can ask for a new tyre to be approved and be added to it.

https://www.actc.org.uk/car-tyre-list-updated/

[Simon Woodall]

can we have any tyre provided the lateral block gaps are no more than 8mm

Simple answer - YES.

The resolution to do this was passed at the April 2018 ACTC Council meeting, which is probably why it has not filtered through yet.
If you can stick an 8mm drill bit into the tyre and it doesn't fall out its OK
But be aware that the blocks on any tyre are NOT of a uniform size (this is to reduce tyre noise).
You need to put your drill bit in several places to be sure.

[Pete Hart]

This is the wording that was approved.

" In addition to the current Tyre List competitors may use any “ Summer” Tyre that will pass a tread gap test with a gauge of
8mm round section. The Test to be performed with the tyre fitted to a rim and inflated to 25psi."

Circumferential Gaps can be ignored.

[Paul Wheatley]

I'm pleased to be corrected! Did I miss this in a recent edition of NOTW? 

[Lee Sample]

Afternoon all,

just sorting out my entry for the Exeter in january, and so i thought i should check the SSRs for 2019.  these still state that the tyres must be on the approved ACTC tyre list.  also, if you look on the ACTC website, there is still no mention of the 8mm gap between tread blocks, and the tyre list itself makes no mention of the new ruling.
does anyone know if this rule amendment is likely to be published anywhere before the Exeter trial? as until it is in writing, surely we still need to conform to the written rules? I just dont want to turn up with different tyres and find that the rule isn't in force yet and get turned away.

cheers,

Lee

[Paul Wheatley (Wheaters)]

The latest, official ACTC list dated October 2018 has some recent additions, along with a supplemental paragraph which states:

"In addition any "Summer" tyre with a max tread gap not exceeding 8mm may be used.
Purely circumferential gaps can be ignored. A tyre will be deemed to have a block gap not exceeding 8mm if when fitted to a rim and inflated to 25 psi a 8mm round bar will stick in the gap when horizontal".

So you're probably OK.

[Stephen Bailey]

. A tyre will be deemed to have a block gap not exceeding 8mm if when fitted to a rim and inflated to 25 psi a 8mm round bar will stick in the gap when horizontal".

Interesting choice of words.... So possibly not the actual rim you are going to use.....