Wheels for your Alfa - A Primer

[Alex Csank]

Gang,

What I am going to try and compile in this thread is as much info as I can on how to select aftermarket wheels for Alfas. Please feel free to contribute any and all useful information and personal experience.

Let me add that I am certainly not an expert in this field, and therefore I do not claim to know everything there is to know about wheels and tires. I am just trying to develop a "one-stop" thread to which all AlfaBBers can read up on the facts they need before they buy aftermarket wheels.

Cheers,

[Alex Csank]

First of all, let's talk about a few basic facts regarding Alfas and wheel sizes.

Wheels are usually measured by:

Bolt pattern - (4 holes or 5 holes?), and hole spacing (4 X 108mm, for example)

Offset - a measurement which determines how far towards the outer edge of the wheel the wheel's mounting surface sits

Diameter - on post-war mass-production Alfas, stock sizing is usually either 14 or 15 inch diameter. Many aftermarket wheels are larger (up to 26" are currently available), but most aftermarket Alfa wheels are kept between 14 and 17 inches. We'll discuss why later.

Rim width - the width of the wheel will determine what cross section of tire you can safely use on a given wheel.

Wheel weight - simply the weight of a rim. The higher the weight, the more unsprung weight your suspension has to deal with.

Hub size and hub-concentricity - this really only applies to some cars (like the Alfetta, GTV6 and Milano). These cars have wheels which are designed to use the wheel centers as a securing point to take some of the bump and cornering stresses. Therefore, it is important to choose an aftermarket wheel which has a hub-centric design compatible with these cars.

Material - some alloys are very strong but heavy, while others are lightweight but brittle. Racers prefer very lightweight wheels, but these may not be very durable for street use.

[Alex Csank]

Now, lets look at Alfa wheels more specifically:

Bolt-patterns - For a very long time, Alfa Romeo used a 4 X 108mm bolt-pattern. This is the pattern used on all Giuliettas (750 and 101 series) and Giulias (105 and 115 series). This includes all GTVs (Bertone coupes) built between 1963 and 1975, all Spiders built between 1966 and 1994 and even the Montreal. The Alfetta design came with a new bolt pattern, in 4 X 98mm. This was used on all Alfetta sedans, GTVs and Sprint Veloces. Coinciding with the introduction of the V6, Alfa introduced the 5 X 98mm pattern. They still use this pattern in modern Alfas. I do not have any information about some of the other (non-US) Alfas like the Alfasud, 33, etc., nor did I include information about the 1900, 2000 or 2600 series (104/106). But perhaps some of our European or Asian friends can enlighten me regarding those sizes.

Wheel diameters - With the large drum brakes used on early cars like the Giuliettas, Alfa used a 15 inch diameter wheel. This was necessary to keep the wheel from rubbing on the brake drums. When Alfa switched to disk brakes, they first used Dunlop brakes (from about 1963) which also necessitated a 15 inch wheel. With the advent of the ATE disk brakes (in 1967), Alfa was able to reduce the rim size from 15 to 14 inches. This was a popular idea back then, as it reduced the weight of the wheels and tires and allowed for the use of more modern radial tires being produced at the time. With the advent of the GTV6 and new radial tire technology, Alfa increased the size of its wheels to 15 inches again. In the '80s, Michelin developed a metric size system which was used on a few cars, including the Ford Mustang and the Alfa GTV6. Some GTV6s came with these odd wheels, which I believe were 390mm tall. If you have a set of these, it can be very difficult and expensive to find tires to fit them today. With the advent of the Milano (75) V6 in North America in 1987, Alfa used a 14 inch steel wheel as a standard size on the lower-priced Silver models, a 14 inch alloy wheel on the Gold models, and 15 inch wheels on both the Platinum and Verde models. The 164 arrived in 91, and used either a 15 inch steel (base model), a 15 inch alloy ('L' - Lusso models), or the unusual 15 inch alloy wheels found on the 'S' models. Modern Alfas use various types of alloy and steel wheels, with sizes between 14 and 18 inches.

[Favali]

Great thread.

Please explain what the letter designation means and the effect a wider wheel has on an Alfa.

E.g. My 93 Spider Veloce has 6J x 15" wheels.

Is the 'J' a profile shape of the wheel rim?

If the 6 is its width, what concerns do I need to have if I move to a 15x7 wheel?

This has a contemporary concern as I am getting prices for Panasports and they are available in 14x6, 14x7, 15x6, 15x7, and 16x7 sizes for Spiders.

Thanks ....
-Rob

[tubut]

The 1900 - 2000 (102) - 2600 (106) cars used 165x400 mm Fergat steel wheels with 5 x 4.5 inch bolt pattern and zero offset. Borrani 165x400 wire wheels were available as an option, using a type 42 hub on the 1900 and 2000 and a larger type 52 hub on the 2600. The wire wheele widened the track by about 2.5 inches in total. An exeption was the 2600 SZ (106.12), which used a 5.00 x 400 wheel and 175 x 400 tires on a Borrani "Turbo Sport" disk wheel that had a steel center with an alloy rim.

Tires were either Michelin "Bibendum" millimetric or Pirelli Cinturato SR variety with inner tubes. Michelin tires are still available today because they are also used on several Citroen models including the famous "traction avant". I heard through Re-originals that about 80-100 Pirelli Cinturatos are produced every year, making them about twice as expensive as the Michelins.

[Alex Csank]

Rob,

I will have lots more to follow, and I'm sure that others will add to it as well.

The 'J' is the term used to describe the lip into which the tire bead is seated. Although I am no expert, I believe that all modern rims are of this type, which is required for use with tubeless tires.

Any rim you buy today in the aftermarket will be of this type, so don't worry about it too much.

The concerns you should have are with respect to back-spacing (offset), ensuring that the wheel/ tire size is of similar diameter to waht is currently on the car (otherwise, your speedometer and odometer will read wrong, and your final gearing - speed in gear - will change), ensuring a good fit under the wheel wells (no rubbing on bumps or in corners) and how the change in weight of the new combination affects your handling.

In general terms, your Spiders wheels can be changed for 15 X 7 wheels very easily and most companies selling wheels specifically for Alfa Spiders have already investigated the offset issues. Some popular choices for your car include Panasports, Serpent Motorsports, and many other wheels available from popular Alfa distributors like International Auto Parts (www.international-auto.com), Vick's (www.vickauto.com) and Re-Originals (www.reoriginals.com).

Good luck and stay tuned for more info as I and others add to the thread.

Cheers,

[Alex Csank]

Thanks for that info, Ruedi! Very useful!

[tubut]

Adapted from a Borrani brochure:

The rim incorporates a well which is required for fitting and removing the tire, as well as two side flanges to hold the beads. In general, the wheel has an asymmetric shape in order to make mre space available for the brake equipment.

The rim is marked by two dimensions which are expressed in inches, namely:

• Width (for example 4" or 4.00") measured between the vertical walls of the side flanges, and
• Nominal diameter, or fitting diameter, measured at the intersection of bead seats and the vertical walls of the side flanges where the angle is 5º.

A third specification of the rim is expressed as alphabetical letters (such as J, JK, K, and C) which correspond to profiles of the side flanges that are controlled by international standards.

[eminence]

Here you can see a table with the original off-set sizes:


Giulia (4-d) 42 mm
Bertone (63-76) 38 mm
Spider (66-93) 38 mm
AR Berlina 38 mm
Montreal 25 mm
Alfasud Serie 1 45 mm
Alfasud Super 45 mm
Alfasud ti Ser2 39 mm
Alfasud Serie 3 39 mm
Sprint (Sud) 39 mm
Alfetta, all 45 mm
Giulietta, all 45 mm
Alfa 33, all 39 mm
Alfa 75 1.6-2.0 45 mm
Alfa 75 2.5 40 mm
Alfa 75 TS/Turb 30 mm
Alfa 75 3.0 30 mm
Alfa 90 2.0 45 mm
Alfa 90 2.5 40 mm
Alfa 145/146
1.4/1.6/1.7 16V 43 mm
Alfa 145/146
T. Spark/Q/ti 50 mm
Alfa 155, Serie 1
(first model) 50 mm
Alfa 155, Serie 2
(wide aches) 41 mm
Alfa 156 41 mm
Alfa 164 TS/V6 40 mm
Alfa 164 24V 32 mm
Alfa 166 41 mm
Alfetta GT/GTV 45 mm
GTV 2.0 45 mm
GTV6 2.5 40 mm
Spider T.S./V6 35 mm
Spider V6 24V 31 mm
GTV T. Spark 35 mm
GTV V6 24V 31 mm

But then there is the additional thing about bolt circle.

Old Alfas have 4x108 mm.
Alfasud/33/75/90/145/146 have 4x98 mm
Big engine (TS, Turbo, V6) 75/90 have 5x98 mm
147/156 have 5x98 mm
166 has 5x108 mm

The center hole has a diameter of 58,6 mm, but from the starting of the Fiat aera (1987) this size changed on new models to 58,1 mm.

If you find a new wheel which fits on a new Alfa, and you would like to use it on your Alfa 33, then you have to enlarge the center hole by 0,5 mm.