Tire Fitment
Thread Starter
Racer
Joined: Sep 2017
Posts: 338
Likes: 56
Tire Fitment
Hello. I have a question about the size of the original tires vs. modern tires. I have a 69 with stock 8" rims., from what I understand the stock tire in 69 was a F70 x 15 which is about equal to a present day 210/215 70 tire. I'm looking to replace my 235- 60 x15 due to age.
I would like to go with a 70 series, just to fill out the wheel well a bit better. Looking at a 225 -70 x 15" tire it states that a 7.5" rim is the widest you can use. So my question is how back in 69 did they get and use a basically 215-70 x 15" tire on to a 8" rim? Magic or are my numbers wrong? Thanks and take care.
I would like to go with a 70 series, just to fill out the wheel well a bit better. Looking at a 225 -70 x 15" tire it states that a 7.5" rim is the widest you can use. So my question is how back in 69 did they get and use a basically 215-70 x 15" tire on to a 8" rim? Magic or are my numbers wrong? Thanks and take care.
Melting Slicks
Joined: Nov 2006
Posts: 3,415
Likes: 1,824
From: Apple Valley, MN
Tire manufacturers typically list a rim width range and a recommended width. As long as your tire of choice falls within the specified range, but may not be a match with the recommended width, it is technically acceptable but sometimes can be visually unacceptable.
A skinny tire on a wide rim stands out visually and is unappealing. Conversely, a wide wire on a narrow rim looks like a blivet - basically stuffing 10 pounds in a 5 pound bag.
The ideal combination is when the radial axis center of the lettering on the sidewalls is at the maximum section width of the tire. For fat tires on narrow rims, the lettering leans inward toward the axle and for skinny tires on wide rims, it leans inward toward the tire OD.
A skinny tire on a wide rim stands out visually and is unappealing. Conversely, a wide wire on a narrow rim looks like a blivet - basically stuffing 10 pounds in a 5 pound bag.
The ideal combination is when the radial axis center of the lettering on the sidewalls is at the maximum section width of the tire. For fat tires on narrow rims, the lettering leans inward toward the axle and for skinny tires on wide rims, it leans inward toward the tire OD.
Melting Slicks
Joined: Dec 2015
Posts: 3,181
Likes: 732
From: Texas City, TX Texas
I'd go with a 235-70 to fill the wheelwell. Check out the gold car post #27.
https://www.corvetteforum.com/forums...ssic-c3-2.html
https://www.corvetteforum.com/forums...ssic-c3-2.html
Advanced
Joined: Nov 2023
Posts: 89
Likes: 59
To answer the original question, if you mount the 225/70 on an 8 inch rim, it will increase the lateral stiffness of the tire and will make the sidewalls work a bit harder. All said and done, assuming you use a quality tire, this won't create any problem re tire safety or longevity. I say this based on 9+ years experience as an engineer in the R&D facility of a major tire manufacturer.
