[concours] Re: Question on tires. More than you wanted to know

Here’s what the current JCNA Rule Book states plus a couple of
observations. Depending on where your car is shown and who judges it,
your wheels and tires may or may not be examined closely. Some judges
may or may not follow all of the available JCNA guidance, including the
implied speed rating requirement.

“1968-1970, Series 2 E-type, Tire Size: 6.40 x 15 Dunlop RS5, Bias; 185
x 15 Dunlop SP41. Wheels: Slotted Pressed Steel 5 x 15; (USA) 72 Spoke
Wire 5 x 15.”
The following notes also apply: “… Only Series 2 E-type car entrants
who can show 185/70 x 15 SP41 tires were purchased prior to 1996 will be
accepted without penalty.”

“JCNA Rules provide that the replacement tires must be the same (or
equivalent) size and type (bias/radial) as original or optional
equipment on cars shipped from the Jaguar factory. The size molded into
the tire will be accepted as proof o currently exhibited size (example:
6.40x15 or 185x15). Wall or stripe/color or width is optional.”

The Rule Book also states: “Tires are considered expendable and may be
replaced only with comparable or superior equipment of original size and
compatibility with the Jaguar. The standard industry tire sizes, which
are moulded into tire sidewalls, are acceptable proof of correct size
without further measurement. There shall be no penalties taken for the
Owner’s preference of white or black wall or red-line cosmetics. Any
brand is acceptable. Type must be consistent with availability for the
vintage of the Jaguar. All five tires installed on a Jaguar presented
for judging must be identical in manufacturer, model, and tire size.”

Note: In JCNA Driven Class, the spare tire is not judged.

The inclusion of the phrases “or equivalent (size)” and “comparable or
superior equipment” in the preceding paragraphs have allowed at least
one owner to protest and deviate from the published JCNA tire sizes, in
order for his chosen replacement tires to be considered acceptable. In
that instance, the owner had Coker Tire provide documentation in which
they stated that the overall physical dimensions of their 195/75R15
radial tires were nearly identical to the dimensions of the original
6.40x15 bias ply tires. In light of the way the rules are currently
written, the JCNA Protest Board allowed the protest and the 195/75R15
tires were accepted.

To the best of my knowledge, the current bottom line is that you must
use 6.40x15 bias ply or 185x15 radials on your Series 2 E-type to meet
JCNA authenticity requirements. If you can afford a tire with an “H”, or
higher, speed rating you’ll be MOST authentic. The wire wheels should be
15x5, 72 spoke with the “smooth” (cast) center hub as contrasted with
the earlier “curly style” (forged) center hub.

There are several wheel and tire suppliers to choose from. Here are a
British Wire Wheel in Santa Cruz, CA is one source that is highly
regarded and can supply both wheels and tires.

Welsh, in Steubenville, OH has recently become a Dayton Wire Wheel
distributor and is advertising very low prices on E-type wheels.

I have no connection to either.

Good luck,
Dick Cavicke