Boosted Falcon

Hey guys, So awhile ago I purchased some Simmons FR20 9.5" rear and 8.5" fronts and only just got tires for them and test fit them to my project car. The rears seem fine, however when I tried to put the fronts on it ended up hitting on the upper suspension.

The company I purchased them from told me they'd fit just like factory ones and have sold them for many different cars Including E series falcons with no dramas. If I used a spacer it'd sit outside the guard as its sitting in the normal position but fouling on the suspension. Any ideas on what I can do to resolve the issue?

Looks like a tire issue, not a wheel issue.

what profile tyres are you running?

wicksy wrote:what profile tyres are you running?

The tires are 225/30 on the front and 275/35 on the rears which I was told was fine and is pretty low profile as it is.

Even if I went down to a 20 profile I'm not sure there would be enough clearance

thats 225/30?

doesn't seem right, 245/30 & 225/35 normally fit with the wheel in a comparable location.

EFFalcon wrote:thats 225/30?

doesn't seem right, 245/30 & 225/35 normally fit with the wheel in a comparable location.

I was told by both the guys at the tire shop and the simmons rep that it'd fit too. I looked around on some of the "Show us your wheels" threads on various forums and it seems people are running similar sized wheels and tires with no problems with the tires fouling on the suspension..

What makes it worse is they wont allow me to swap for smaller profile tires and pay the difference if there is any.

Thats just terrible customer service, especially if they were the ones who suggested the tyre size to you etc...

Also without sounding like a smart ass, you are sure u got front and rears around the right way, and the tyres are on the right wheels?

Did you get the same profile tyre front n rear?

A 19" and 20" with say 245/30 will have different rolling diameters. 245 is the tread width in mm. easy. 30 is the ratio of side wall height compared to tyre witdth.

So the sidewall height is 30% of 245mm = 73.5mm (x2 = 147mm)

19" = 482.6mm
19" = 629.6mm with sidewall height

20" = 508mm
20" = 655mm with sidewall height

You simply need tyres that have a smaller rolling diameter. Whether they exist or not idk


The other thing I want to mention is sometimes tire fitters leave ridiculous tire pressures. Make sure you not at 55psi or something.

I am running 245/35R19 and had no clearance issues and according to tyre calcs and conversions that has a larger diameter than your 225/30R20 and its also wider.. So really bizarre you are having clearance issues!

245/35R19 is 9.65" wide and 25.8" in diameter
225/30R20 is 8.86" wide and 25.3" in diameter

Have you checked for the offset stamp in the rims? You would be looking for a stamp saying ET then a number..

ROOSTA wrote:245/35R19 is 9.65" wide and 25.8" in diameter
225/30R20 is 8.86" wide and 25.3" in diameter

Lol imperial makes my brain hurt
655mm
643mm