> Does anyone know the specifications of the original TR2, 3, 4,4A tyres.
> The specific info I need is their diameter.
> I know that they were 165 SR 15's.
> The reason for the query is that I have non standard tyres and wish to get
> back as close as posible to the original diameter.
If you really want to get it right (note that there were different tire
options available at different times, each with it's own rolling diameter)
... look for the calibration number printed on your speedometer face.
Should be a 4-digit number, somewhere around 1100 to 1400. Take that
number, and multiply it by 2.5, then divide by your differential ratio
(which is usually 3.7). The result is the turns per mile for your original
tires. Since most tire vendors give rolling diameter in turns per mile,
this is exactly the number you need.
ISTR 1152 was one of the common calibrations (my TR3A is very unusual with
it's 1355 calibration). So, 1152 * 2.5 / 3.7 = 778 turns per mile.
For some reason, Tire Rack doesn't list the tpm for the Kumho PowerStar 758
but the overall diameter is listed as 25.4 inches, which would be 794 tpm if
the tire didn't deform under load. Since it does, it should be a very close
match to the original tires.
Randall
Check out the new British Cars Forum:
http://www.team.net/the-local/tiki-view_forum.php?forumId=8
|