sick-slick
New member
What was the maximum rim size for the factory optional wheels on the 128 3p Berlinetta 1300? (stock were the 13”x 4.5”).
I have Cromodora CD30 in mine they are 5.5".
I have an original sales brochure for a berlinetta special series which says it comes with 'sports' steel wheels.Doesnt mention alloys.
Well I'm (almost) 100% certain the track/wheelbase specs are identical for the 3p and the coupe, as they are both based on the shorter (and quite different to a sedan) floorplan ... I only have coupe literature, and the front track is listed as 4' 4 1/8" (52.125 inches is 1324mm) and the rear track as 4' 4 1/2" (52.5 inches is 1333.5mm) so I would say your closer than he is. (literature I have is pre 1974 so pre metric)
Factory brochure only lists the fact that there is a factory alloy wheel that is "available as optional equipment" ... but shows no pictures or sizing. I'm quite certain for the coupe that these were 4.5 inch CD8's.
Most times the factory alloy wheel is the same width as the steels (124/125/131/132) the X19 being one of the exceptions with 5 x 13 alloys, and the same 4.5" steel wheels as the coupe/3p)
IMO... You will run out of allowable increase in track width before you get the 6" rims on ... and inwards you will run into clearance problems with the front strut / tyre ... the RTA inspector will want to see a good "couple of fingers" clearance between the strut and tyre ... so unless you want to change to small diameter coil overs, this and the track width will be limiting factors.
I had 6 x 13s on my 128 sedan (which were quite a "deep dish" -positive offset- wheel and were on it when I aquired it) and pretty soon I changed to 5.5 x 13 CD11's ... which are far less positive offset.. and my 128 definitely steers better with far less scrub radius (which is what you will get with a positive offset rim) as you shift the tyre contact patch away from the (theoretical) point where the strut centreline intersects the ground, which is actually the point about which the tyre rotates. The wider the tyre and the greater the scrub radius, the greater this "scrubbing" action will be. This makes the steering heavier, makes a car more likely to follow surface irregularities, and makes a car much harder to "turn in" under brakes.
SteveC