[DeTomaso] FOR Sale Rant

John Taphorn jtaphorn at kingwoodcable.com
Sat Sep 19 17:23:52 EDT 2009


Will

I agree; it is unacceptable to require spacers when ordering custom wheels. 
I also think it is an unnecessary compromise to accommodate the wheel's 
spacing unless you are willing to compromise on the flare width and or are 
getting a terrific pricing deal on the wheels.  It sounds as if you are in 
neither of those camps.

You have received a lot of good advice on this Forum and I also feel 
compelled to add my 10 cents.

Your visual observation is correct that a 15" diameter wheel cannot 
accommodate much more backspacing because the inner lip will contact the 
lower outside hub carrier outside nuts.  You will need to go to at least a 
17" wheel to clear the obstacle.

To maximize the wheel width and subjectively optimize the wheel body 
appearance, perform the following exercise.

1) Raise rear of the car and remove the rear wheels. Place a block under the 
hub carriers.
2) Lower the car until the lower suspension arms are parallel to the floor.
3) Tape a weighted string to the top of the rear fender so that the string 
falls in front of your wheel mounting surface. (For most of us that is the 
stub axle)
4) Measure the distance from the string to the wheel mounting.  This will 
give you a dimension for your front spacing.

If you are looking at the car from the rear, this front space measurement 
will align the outside wheel flush with the rear 90 degrees of the rear 
fender arch.  From the front, the wheel will appear tucked in a bit.  OTOH, 
you could add about 1/2 inch to your FS measurement and then from the front, 
the wheel will appear more flush; however, from the rear, it will appear to 
stick out beyond the fenders.  I prefer the look of the former; yet, I've 
seen the latter on some vendor's larger campy clones. Despite the latter 
measurement sticking out from the upper fender, under suspension 
compression, the wheel assembly pulls into the wheel well so quickly, that 
there does not appear to be clearance issues against the body with rolled 
fender lips on any such fitted cars that I have observed.

The amount of backspacing that you can engage will now depend on the 
diameter of your wheels.  Since you are going for 17s, you can clear the 
lower hub carrier nuts and extend beyond 6.5". Your wheel width will be the 
sum of your front and rear backspacing.

Confusion reigns with FS and BS measurements because some manufacturers 
measure it from the outside lip of the rim, while other from the inside 
mounting surface.  The difference is 1/2 inch on each side.  Thus an 11" 
wheel for one vendor equals a 12" wheel from another.  Be careful here that 
you are using the same terms.

I run 18" wheels that are 12" wide measured from outside rim edge to outside 
rim edge on a stock bodied car with an extended rear upper a-arm.  If we 
measure spacing from the outside edge of the outer lip, my front spacing is 
5" and my BS is 7".  I run a 335/30/18 rear tire and it is flush with the 
back 90 degrees of the rear fender.  However, there is a compromise to wide 
tires and it is only a problem if you drive your car in a way that severely 
compresses your rear suspension.  Eventually, any tire will scrub the upper 
inner frame rail under suspension.  Wider tires will contact that frame rail 
sooner with less suspension compression.  Be certain to grind smooth the 
weld joints that are in that area or weld splatter could cut your inside 
tire wall.  On  my car, if I were to run additional backspacing, the next 
clearance issue is the bracket for the muffler mount.  I now have about 1" 
of clearance or room for additional backspace.

I hope this helps.  As Chuck Engles made clear to me - and I've never 
forgotten it- Measure carefully - you don't want a set of boat anchors.

JT

----- Original Message ----- 
From: "Will Demelo" <wdemelo at cogeco.ca>
To: <detomaso at realbig.com>
Sent: Saturday, September 19, 2009 8:56 AM
Subject: [DeTomaso] FOR Sale Rant


>I appologise for last weeks post with the expletives.
> I am trying to convert my car to GR4. The fibreglass flares are going to 
> be riveted on, just as from the factory.
> I ordered wheels from a vendor last fall and the agreed upon price was not 
> charged to my card. Apparently there was more machining involved. After 
> waiting 3-4 months, I gave up and cancelled the order. The wheels had not 
> beed started yet (confirmed by Kodiak). I had to threaten credit card 
> fraud to get my money back.
> I recently placed another order to another vendor. I was told that they 
> had converted many cars. I mounted the flares on my car using clamps and 
> took measurements to the hub surface.
> After requesting the backspace measurements 3 times, I was finally told 
> 4.5"F and 6.5"R.
> The reproduction Campys I have on my car now, with stock narrow body, have 
> a 6.25" backspacing. Now I'm no math major, but how are new wheels, with 
> almost the same backspacing be correct after I extend the flares outward 
> about 4"??
> I was told by the vendor that I was doing things backwards. I should get 
> the wheels and then modify the flares to accomodate. I don't agree with 
> this. There is zero movement with my flares. They have to meet front and 
> rear body lines and then the upper portion gets pushed to meet the body.
> I don't inderstand how I can't mount my flares to the body, take 
> measurements and order wheels with custom offsets.
> Ron L has just spent $5500 on GR4  wheels from a vendor and he requires 1" 
> spacers in the rear. I know of another fellow with a factory GT5 and the 
> GR4 wheels he ordered with "factory" specs required 1 1/2" spacers in the 
> rear and 3/4 in the front.
> I'll be damned if I am going to spend uwards of $5k to then have to 
> replace studs and install spacers.
> I try my best to send all info and communicate to only have vendors ship 
> me parts, at my expense.
> Will
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