Reply to "Sticky #7: Tires for OEM 15 inch wheels"

SOURCING TIRES

Tires for the original 15" Campagnolo wheels can be sourced from "classic tire" suppliers or sourced from "contemporary tire" suppliers.

Re-issues of classic tires are "reproductions" in appearance and size, but they are constructed using modern rubber compounds and modern construction techniques. They "look" like the classic tire they are emulating in sidewall design and tread pattern, they are available in the right size for your car, but they are thoroughly modern in terms of performance.

Longstone Classic Tyres of Bawtry, South Yorkshire, England, is the only "supplier" of reproduction tires who has shown an interest in our classic Italian cars. Longstone's US distributor is Lucas Classic Tires of Long Beach, California. Classic tires of the proper size for some applications are available from Pirelli, Michelin, and Avon.

Longstone Classic Tyres

Lucas Classic Tires

Avon Tires are also available in the US via Frisby Performance Tire (Park City Illinois), Roger Krause Racing (Castro Valley California), SascoSports (Alton Virginia), or Sierra Tire (Henderson Nevada).

The availability of contemporary tires for 15” wheels has been dwindling over the last couple of decades; especially for tires having a speed rating of V (or higher). The options in selecting the same make and model tires in the front as you select for the rear are highly limited.

Here are two good internet sites for checking-out what's available amongst "contemporary" tires, they both allow you to search by size for "sets" of tires wherein the front tires and rear tires are a different size:

Tire Rack.com/

On Line Tires.com/


CARING FOR MAGNESIUM WHEELS

The purpose behind using 15 inch tires is of course to continue using the factory 15 inch wheels. So lets touch on care of magnesium wheels for a moment.

If your Pantera's magnesium wheels have never been serviced (most haven't) they should be serviced. The older the Pantera is, or the more miles it has on it, the more important this is:

  • The wheels should be visually inspected for curb-rash damage and damage from crimp-on balancing weights. If the wheels were holding air pressure and there is no visibly "severe" damage, its OK to proceed.
  • If one or more of the wheels aren't holding air pressure, or if you want to be more thorough, the wheels should be tested for cracks and porosity. But there are few places that can repair magnesium wheels, so unless you have such a place near you, you'll have to ship them somewhere for repair. Pantera Parts Connection of Reno Nevada can provide full service of the wheels, including repairing damage, cracking, and porosity.
  • At this point you must decide whether or not to remove the OEM paint finish prior to annealing the wheels. Magnesium wheels have a layer of zinc chromate below the primer and top coats of paint. This chromate conversion coating is not anti corrosion protection ... it provides a finish that primer paint can adhere to. If you remove this chromate coating it must be replaced. If you don't chromate the magnesium before painting you can guarantee that your beautiful paint finish will lift off some time in the future. If you choose to leave the OEM paint on the wheel then remove the decals, balance weights, adhesives, clean-off all dirt, brake dust, and grease. The paint shall turn brown in color during the annealing process. If you choose to remove the OEM paint then do so employing a gentle blasting process such as plastic beads, walnut shells, etc.
  • Anneal the wheels at 375°F for one full hour after being brought to that temperature, then cool the wheels as slowly as possible (i.e. turn the oven off, but leave the oven door closed, and let the oven slowly cool until it reaches room temperature).
  • if the wheels were annealed without removing the OEM paint then after annealing prepare the OEM painted surfaces to make the paint suitable as a "base coat" for the new paint, using caution to remove as little paint as possible and to avoid exposing bare metal. The best surface prep where bare metal has been exposed is Dow 1. You just wipe the Dow 1 on and leave it on for 3 minutes. The exposed Magnesium should at this point change to a rich brown or gold color. Then wash off the Dow 1 with clean tap water.
  • If the paint and primer were removed prior to annealing then clean the bare magnesium after annealing with Dow 19 and a Faber Castell fiber glass tipped pen (available from arts supply shops). These pens are for use in place of a scotch bright cleaning pad. The Dow 19 will also lightly chromate the surface as it cleans. You may see the surface turn slightly brown or gold. It is essential that you remove EVERY TRACE of corrosion before moving on to the final steps (prime and paint).
  • Instead of Dow 19 a fresh coat of  zinc-chromate primer can be applied, if you can find it. Some say zinc-phosphate can be employed as a substitute for  zinc-chromate, I have not verified this. When substituting zinc chromate it is important that the substitute shall provide a coating that primer paint can adhere to.
  • The final steps are to prime and paint the wheels. DO NOT SAND the chromate surface prior to painting. Wipe off finger print oil, etc. with a professional auto painters grade wax and grease remover. Then prime and seal with 2 part epoxy primer. Modern primers are most likely chromate free, but if you can find a primer with chromate in it so much the betterAltex AltraBond 3094 is a chromate free etching primer used and certified by the aerospace industry for priming magnesium parts.   

OEM TIRE SETS


Tire Set 1 | 1971-1972 | 185/70VR15 + 215/70VR15 
Push Button, Pre-L, Early GTS, Early Group 3
Chassis number 1001 through 4268

This set is available in Michelin XWX re-issues. There is little demand for this size however.

Most owners of the earliest Panteras opt for tires in the sizes of tire set 2 or tire set 3; which are by far the two most popular and therefore most common tire sets for narrow body Panteras.


Tire Set 2 | 1972½ -1977 | 205/60VR15 + 255/60VR15 
Pantera L, GTS, Group 3
Chassis number 4269 through 7554, and 9001 through 9099

This set is available in BF Goodrich Radial T/A (speed rated S).

205/60VR15 tires (V speed rating) were original equipment on 1987 - 1995 Acura Legends, various 1986 - 1994 Audis, 1995 - 1997 Honda Accords, and 1986 - 1991 Mazda RX-7s. Kumho and Pantera Tire currently manufacture 205/60VR15 tires. There are probably others I haven't found.

The 255/60R15 is also available in Pirelli CN12 re-issues (speed rated W). Alternatives to the 255/60R15 rear tires are tires sized 275/55R15. The Avon CR6ZZ "classic" street legal radial racing tire is available in this size.

Combining one of the 205/60VR15 front tires with the Pirelli Cinturato CN12 or the Avon CR6ZZ rear tire would result in a "mixed" set of tires speed rated V (higher than a set of Radial T/As).


Tire Set 3 | 1978-1984 | 225/50VR15 + 285/50VR15 
Late Model GTS, Late Model Group 3
Chassis number 9100 through 9374

The Front is available in Pirelli P7 re-issues and in Pirelli P-Zero System.

THE REAR IS NOT AVAILABLE ANYWHERE.

Dougal Cawley of Longstone Classic Tyres says "I am in talks with Pirelli about the 285/50R15 size tire, but it is not as yet set in production. It will take time. Please be patient." By taking time, he means "years".

The most common substitute tires for the 285/50VR15 tire are in the size of 295/50R15 (speed rated S). There are about 5 manufacturers supplying tires in this size: BF Goodrich, Cooper, Hankook, Milestar and Mastercraft. The Avon CR6ZZ "classic" street legal radial racing tire is also available in this size, but not in 225/50R15 for the front.

A great number of owners of 1971-1977 Panteras retro-fitted their Panteras with factory 10x15 rear wheels, and moved the 8x15 rear wheels to the front position, in order to accommodate the tires of set 3. Every 10x15 wheel that De Tomaso had stocked, at least a cargo container full of them, sold-out long ago. The 10x15 wheel remains popular even though the proper tire hasn't been available for years. When a used set of 10x15 wheels comes-up for sale, they sell quickly at top dollar prices. There are not one but two aftermarket companies manufacturing this wheel still today (Roin and Marvic). I know Pantera owners who have purchased second Panteras simply because the second Pantera was equipped with this size rear wheels. They removed the 10x15 wheels, replaced them with 8x15 wheels, and placed the second Pantera up for sale again. The point is that this is a very popular tire set amongst Pantera owners. There are a far greater number of Panteras set-up to use tires in the sizes of tire set 3 than production numbers would indicate.


Tire Set 4 | 1978-1990 | 285/40VR15 + 345/35VR15 
Wide Bodies: GT4, GT5, GT5-S
Chassis number 9100 through 9374, and 9375 through 9562

This set is available in Pirelli P7 re-issues.
The rear tire is also available in Pirelli P-Zero System


Tire Set 5 | 1990-1993 | 235/45ZR17 + 335/35ZR17 
Wide Body: Pantera Si
Chassis number 9601 through 9641

This tire set is available from 2 manufacturers, but it is not available in the same model tire for front and rear.

Michelin: Pilot Sport 4S front + Pilot Sport PS2 rear
Pirelli.: P-Zero Nero GT front + P-Zero System rear


Two Non OEM Options:


Historic: Back in the 1990s owners of "Pre-1978" Panteras (approximately 6,654 Panteras) wishing to upgrade to low profile tires could "Plus 1" or "Plus 3" the tires for their Pantera by choosing Pirelli P7s in in the sizes of 225/55VR15 on the front and 275/55VR15 on the rear. The 225/55VR15 front tire was optional equipment on the 1992 through 1997 BMW three series, the 275/55VR15 rear tire was standard equipment on the Bentley Turbo R, 1985 through 1992. This was a bitchen tire set for the Pantera while it lasted. These tires aren't available today, so I'm mentioning this tire set more as a bit of historic information rather than an option available to us today. If "high quality - speed rated - passenger car tires" should ever become available in these sizes again such a tire set would become my personal preference. But I'm not hopeful that shall ever happen.

Contemporary: This option IS available today. Purchase a pair of reproduction wheels from Roin Technology directly or via Mr.Fiat, but rather than 10x15 order 10x17 instead (I'd recommend 13mm positive offset). Mount 225/50ZR15 Pirelli P-Zero System tires on the OEM 7x15 front wheels, and mount 285/40ZR17 Pirelli P-Zero System tires on the new rear wheels. The fender openings are 2 inches different in diameter front to rear, and the tires are a bit more than 2 inches different in diameter front to rear. The 2 inch difference in wheel diameter emphasizes this difference, it is quite dramatic looking. The sidewalls of the rear tires are 1 inch shorter for better handling too. The tire set is contemporary rather than a re-issue, and the sizes are readily available. AND it looks factory original.

-G
.

×
×
×
×