The Official 356Talk Forum

I have a set of Tecnomagnesio wheels and I would like to know if anyone has them on their Pre-A. I am currently running 15X6 Fuch wheels with disc brakes and I want to go back to drum brakes with 15X5 Tecnomagnesio wheels. Before I swap everything back and find out I have to deflate the tires to install them please let me know if they will fit. The Fuchs fit without any issues due to the rotor/hub being smaller than the original brake drum and I fear I will not be able to get the Tecnos on/off without deflating the tires.

Thanks in advance for your help!
Frank

Hey frank, depends on what size tire you are installing. The rim itself will fit just fine but you'll have troule installing even a 155 size width tire. (That's about a 5.50 on a 16). 145R15 would most likely clear the rear fenders but it will look silly on a 5" rim.

Jules

I'm thinking about 185/65/15 tires and have come to realize I may have to carry a portable compressor just in case.

Many thanks
Frank

Frank,

with 99% certainty those will not clear even when completely deflated. There is simply not enough clearance between the drum and the rear wheel arch.
iI had to deflate thr 5.50x16s to get them to clear on my 52 (with stock 280mm drums), and that is about the width of a 155 radial. Highly doubt you will be able to squeeze a 185 in there. I have 185/70 15 on my 57A and those barely clear.

Happy New year to all!

Have 5" alloy wheels (purchased from Wilhiot a few years ago) installed and the tires are Michelin 165 - 15". They are not Tecnomagnesio wheels but sure look similar. Pretty sure the tires need to be deflated to fit on the rear ... very tight clearance. Have to agree with Jules that you are dreaming to think 185 would ever clear the body, the 165 is really tight.

Here are original 6" Technomagnesio's we just had installed on my son's '56 sunroof coupe by Franz Blam. (Look him up, Franz Blam Racing, 84 y/o Porsche factory trained back in the day.) It was quite a task, longer studs, spacers and the holes in the wheels had to be drilled to fit the standard diameter studs. No clearance issues except slight rub on full lock, a common issue with P185/65/15R tires.

Happy New Year,
Bob Slayden
Keep 'em on the road

Pre A's are a different animal, Bob. I ran 5.5x15 with 185/70/15 on my T1 with no problems. The rear axle goemetry on a pre A is different from a T1/ A

Jules Dielen wrote:Pre A's are a different animal, Bob. I ran 5.5x15 with 185/70/15 on my T1 with no problems. The rear axle goemetry on a pre A is different from a T1/ A

The geometry is not different. The fender opening is much tighter.

Doesnt the lower bump stop for the spring plate limit travel a lot more on the pre A?

Yes. it limits the travel. That does not change the basic geometry.

ok that is what i meant. Less travel, not as big an angle when you lift the car, so less room for a tire (in addition to the fender arch)

Jules Dielen wrote:ok that is what i meant. Less travel, not as big an angle when you lift the car, so less room for a tire (in addition to the fender arch)

Exactly right.

Just knock a little off that stop where the spring plate hits with a small ziz wheel and it makes things a whole heck-o-a-lot easier as far as tires going on the rear. It doesn’t take much,...just a little bit because the stop is fairly close to the pivot point so by the time the extra travel gets out to the axle point the drop is magnified.

Thank you all for your knowledge and suggestions!

Not sure when I'll be going back to drum brakes but I'll be sure to post the outcome.

Thanks again
Frank

just go with the early Pre A 230mm drums. Easy access, but complete lack of stopping power. Can't win them all