Concave vs. Convex Wheels - 328 & Mondial

There are 328s with convex wheels and no ABS. The ABS came later.

FYI, I'm pretty sure the early Mondials also had convex wheels

 

The wheel changeover for 328 had to do with the suspension changes that could accommodate the ABS (but a 328 with the new suspension didn't have to have ABS installed as Tillman noted).

And even though the early Mondial wheels look more the 308 wheels, they are really in the convex family. The photos in this post:

http://ferrarichat.com/forum/showpost.php?p=137934141&postcount=1643

show it well -- especially the 3/4 rear shot showing a 308 and Mondial parked together at the curb.

 

The switch to convex wheels on the 328 had to do with suspension changes necessitating a change in wheel offset, it was not because of ABS. The switch to convex wheels came with the 88.5 cars. Supposedly in Europe ABS was optional on the 88.5 328s, but I've never seen an 88.5 with ABS in person or in pix. In the USA, ABS was not available on 328s until the 1989 model year and then it was std equipment.

Best regards,
Dino

 

The Mondial from 1980 on had a similar suspension as the 308 but with longer A-arms therefore the need for higher offset wheels. In 1988.5 the 328 got the Mondial A-arms, not a new design but basically the 1980 Mondial design.
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The suspension change neccesitating high offset wheels was to have a near-zero scrub radius, which eases steering effort and minimizes steering kick-back - which is critical for an ABS car.
In 1980 on the first iteration of the Mondial cars brought the ( F1 politically driven decision to use) Michelin TRX tires with a whopping 240 section at all 4 corners with unassisted steering at the front. Despite the use of minimal scrub radius, the steering effort was high, even for a Ferrari, despite the minimum scrub radius. This started a long story of trying to make up for initial mis-steps with with Mondial. When ABS was introduced by Ferrari for the first time, the Mondial was the natural car to do it in. You need minimal scrub radius, or if the ABS differentially brakes the front wheels it can jerk the wheel out of your hand.

 

I would add that the ABS sensors are quite small and mounted inside the wheel. The idea that the convex wheels were needed for more room is one of those urban myths. Snj5's comments about scrub radious being important for ABS is the first I've heard of this, but I am not an engineer so will defer.
On a more personal note, I have owned 328's with early and late suspensions and I greatly prefer the feel of the later setup, but I do like the looks of the concave mags better.

Dave

 

It has concave wheels and ABS. I was told by my dealer that 88.5 was significant because it was the first use of ABS in a Mondial.
Ron