[DeTomaso] Rim Offsets

[MikeLDrew at aol.com]

In a message dated 7/3/13 9 29 36, steve at snclocks.com writes:


> 
> Mike – thanks for the extensive comments.  I do plan to drive 5332 for a 
> while, get used to it and see how it all hangs together. 
>   
>  Right – scrub radius.  As I understand it, increasing scrub radius makes 
> it easier to park the car but more sensitive to external forces acting on 
> the tires when rolling down the highway – like uneven brake application.  
> Oh, and “excessive” scrub requires more steering effort when going down the 
> road and increases the “feel” of the steering. 
>   
>  In my feeble brain, if the inside of the rim is at the same place with 
> both 7 and 8 inch wide rims,
> 
>>>...which it's not...

> > well, going to an 8 inch rim increases scrub radius by a quarter inch.  
> Of course, I don’t know that inside edge of 7 and 8 inch rims are at the 
> same point.  But, since you indicate that the 8 inch rims improve handling, 
> I assume this means that the offset is increased a bit.  You indicate that 
> increasing scrub radius improves handling – does that include reducing 
> tramlining?  Or am I really just asking too nit-picky of questions?
> 
>>>You're absolutely asking too nit-picky of questions...but that's why we 
are all here.   We love this stuff! :>)

The outside of the wheels is in the same place.   The 8-inch wide wheels 
are one inch wider on the inside.   If the tire size is the same (that is, you 
take a tire off the 7-inch wheel and put it on the 8-inch wheel), the 
center of the tire is moved inboard by 1/2 inch.   That makes a fair difference.
>   
> > From your e-mail I conclude that a set of four 8 inch wide original rims 
> is the way you would recommend for my situation – if the Coddingtons leave 
> me feeling like I would want to make a change?
> 
>>>Yes, although it will be difficult to buy a set of four, 8-inch wheels.  
 You might wind up buying two sets of 7s and 8s to get there, and then 
selling the 7s to some Mustang guy.   Alternately, the easy solution would be to 
just buy one set and put them on the car.
>   
> > Which Coddingtons.  The gentleman who put them on told me that they were 
> special, an early set with a flat center section instead of the dished 
> shape of the later ones.  This apparently requires unusual lug nuts which are 
> counter sunk.  I am speaking from my notes here, and will have to see what 
> I can figure out when Passport drops it off this afternoon.
>   
>  See what you think.  5332
> 
>>>That is a VERY nice-looking car!   I assumed you were speaking about 
Coddington's Campagnolo clones, as opposed to these, rather more generic (but 
very striking) wheels.
>   
>  >Looking at the pictures one more time, I will have to see how it drives 
> and rides.  You are right – gads, good looking rims.
>   
> >>>Yes, these look quite good indeed.   My earlier comment was that their 
current-production Campagnolo wheels are revolting to look at...but these are 
a completely different story.

I think when you drive the car, you will quickly get used to it and enjoy 
it.   There's a lot to be said for having a lot of traction and feeling 
planted in the corners, rather than skating around as you would on old-school, 
low-tech tires.

Mike (who skates around on old-school, low-tech tires....)