<VV> LM tire diameter

[Bruce Schug]

On Apr 21, 2008, at 10:42 AM, Mark Corbin wrote:

> If you look on the LM speedo info tag (on the back of the cluster)  
> you'll
> see that the speedo is rated at 825 revolutions per mile. That  
> figures out
> to be 24.44 inches of rolling diameter. DISREGARD TIRE SIZE (and what
> others might say), BUT the 24.44 rolling diameter is what you should  
> look
> for.
>
> -Mark
>
>
>> [Original Message]
>> Subject: Re: <VV> LM tire diameter
>>
>> On Apr 20, 2008, at 8:52 PM, Michael Kovacs wrote:
>>
>>> Darn. I thought I saved the info, but can't find it. What is the
>>> generally accepted correct tire diameter for a stock 7.00 13 that
>>> came with a LM?
>>>
>>
>> Short answer: 25.3"
>>
>> Long answer: There were differences in diameters of production
>> 7.00-13's. The information I have lists diameters of: 25.1, 25.1,
>> 25.3, 25.4. This was for four Firestone tires. The Tire and Rim
>> Association lists 7.00-13's as being 25.2". But, remember, this was
>> just a spec, it doesn't represent actual tires. As a "par" figure, I
>> use 25.3" or if you prefer fractions, 25 1/4".
>>
>> Bruce W. Schug
>
>


Mark,

The question was, "What is the generally accepted correct tire  
diameter for a stock 7.00 13 that came with a LM?"

I answered Mike's question above. The answer is 25.3"

The question you answered was, "What diameter tire should I use if I  
want to have an accurate speedometer and odometer?"

The answer is, one that provides 825 revs/mile.

These are two different questions, two different answers, and probably  
two different tires. The obvious reason for this is that on an  
original Corvair, the tire diameter was incorrect to obtain correct  
speedometer and odometer readings. Everyone knows, they weren't  
accurate. The reason they weren't accurate is because the tires  
weren't of the correct diameter to make them accurate.

Bruce


Bruce W. Schug
Treasurer, CORSA South Carolina
Greenville, SC
Stock Corvair Group Member
bwschug at charter.net

CORSA member since 1980

'67 Monza. "67AC140"