Alfa Romeo Owners Club of Australia Forum

Technical => 116 Series (Alfetta Sedan/GT/GTV & Giulietta Sedan) => Topic started by: Southern75 on May 28, 2013, 07:29:55 PM

Title: Max tyre width on 75
Post by: Southern75 on May 28, 2013, 07:29:55 PM
Hello all,

I need new tyres on my 75 ... I don't drive it much ... and was really keen on getting something a bit ... sportier.

Everyone is raving about the new Kumho Ku36 which is virtually an r-series ... but it only comes in a 215/45/16 I'm crueently running 205/45/16 .... do you think this will rub?

I don't think it will at the rear as i did have 225's on another set of rims (looked awesome) but they rubbed badly at the front.

What are people's experiences?

Do i have to get guards lipped or what?
Title: Re: Max tyre width on 75
Post by: scott.venables on May 28, 2013, 10:17:48 PM
What width and offset are your wheels?
Title: Re: Max tyre width on 75
Post by: Joe Falcone on May 29, 2013, 09:01:49 AM
Hi
I'm assuming your wheels have the same offset as standard rims and are not over 6.5 inches wide. 215 45 16 is way too big for fronts and can rub in the rear as well if cornering hard. From my experience 205 45 16 is ok only if not braking heavily and you'll still get a small amount of rubbing at full lock steer. The front is always going to be the problem when upsizing wheels on a 75 unless you give more negative camber, stiffen the suspension, etc, etc.
Joe
Title: Re: Max tyre width on 75
Post by: Paul Gulliver on May 29, 2013, 11:43:27 AM
QuoteThe front is always going to be the problem when upsizing wheels on a 75 unless you give more negative camber, stiffen the suspension, etc, etc.

This is Joe under brakes. Static measurements don't always give you the right answers.

Title: Re: Max tyre width on 75
Post by: Joe Falcone on May 29, 2013, 04:24:23 PM
onya paul
i was on 195 60 14 that day still had the standard sway bar and as you can tell was bottoming out ripping holes into the inner guard linings. had to move the bonnet cable too. ive since upgraded to a 75 3 litre bar which is 1 mm thicker and has helped. i now run on 205 50 15 with the front guards lipped, have no rubbing  :)
joe
Title: Re: Max tyre width on 75
Post by: Southern75 on May 31, 2013, 06:14:46 PM
Ahh well,

I have 205/45/16 on 7.5" simmons so the side wall is already stretched.

I did have a set of 15x7" simmons ... which had 225's and they were a little rubby at the rear but didn't work at all on the front.

It is a street car so the idea of huge stresses isn't going to happen.

Title: Re: Max tyre width on 75
Post by: Southern75 on May 31, 2013, 06:19:17 PM
Isn't 205/50/15 a bit small in diameter for a 75? I woulda thought a 55/15 was about right.
Those afore metioned rims (the 15" ones) ... standard offset (or very close to) has 225/55/15 and the rolling diameter was very similar to the standard 195/60/14.

the 205/45/16 is pretty much identical to standard rolling diameter.

I think the guard lipping might be a pretty good option.
Title: Re: Max tyre width on 75
Post by: Joe Falcone on May 31, 2013, 07:13:21 PM
195 60 14     589.6 mm
205 50 15     586.0 mm
205 55 15     606.5 mm
205 45 16     590.9 mm
215 45 16     599.9 mm
225 55 15     628.5 mm
Title: Re: Max tyre width on 75
Post by: Southern75 on June 02, 2013, 10:22:11 AM
Fair enough