Need tire/wheel measurements

[all-world1]

I'm doing my engine/trans/rearend mockup without wheels and tires, so I plan on setting my front spindles, frame and rearend at the correct height above ground level for this process.

I'm going to be running 5.60X15 on the fronts and P235/75 15 on the rear. If any of you are currently running these sizes, I would really appreciate your measurements from ground to center of hub

Craig

 

[EX JUNK]

Mathmatically they work out to an OD of 23.96" and 28.87". Dividing by 2 you get a center of 11.98" and 14.39" respectively.

Jim

 

[all-world1]

Mathmatically they work out to an OD of 23.96" and 28.87". Dividing by 2 you get a center of 11.98" and 14.39" respectively.

Jim

Thanks Jim. Since tires are compressed against the pavement, the ground-to-hub distance would likely be less than hub-to-top of tire. I'm probably being too anal on this one, I suppose using your measurements would be good enough for mockup.

 

[EX JUNK]

Thanks Jim. Since tires are compressed against the pavement, the ground-to-hub distance would likely be less than hub-to-top of tire. I'm probably being too anal on this one, I suppose using your measurements would be good enough for mockup.

The amount of deflection would depend on the weight of the car and the amount of air pressure. Those numbers can vary from car to car.

Jim

 

[der Spieler]

You can go to any of the tire manufacturers websites or to Summit or Jegs and get specs for tires including cross sectional dimensions which can be used for help in figuring wheel backspacing. A general rule of thumb often used is to subtract 1/2" from the tire radius, ground to center of hub, to account for the tire's compression.

 

[EX JUNK]

How do you figure a tire size? The first number is the cross sectional width (not the tread width which is usually narrower). The second number is the aspect ratio which is the ratio of the cross sectional width to the height of the tire from road to rim. And the third number is the diameter of the rim. Most tires today that first number is expressed in millimeters and to convert it to inches you must multiply by .03937.


In the size in question 235mm converts to 9.252". Multiply that by .75, the aspect ratio, and you get 6.939". Then double that, because there is a top an a bottom of the tire, and add in the rim diameter and you get the OD of the tire which in this case is 28.878".

When you are figuring the "classic" tire sizes the first number is already in inches so there is no need to convert. Since there is no second number, the aspect ratio, it is assumed to be 80% or .80. That figures out as 5.60"x.80=4.48"x2=8.96"+15"=23.96".

Jim

 

[jdwhip]

try this web site for tire sizes/height

sstire.com

 

[all-world1]

Thanks everyone for your input.....this gives me more than enough info to git 'er done.

 

[Ted Brown]

I now set my suspension and frame up with the frame ON THE TRAVEL STOPS, DOWN travel, that way you are safe when you make your mounts for everything, shocks and engine mount, steering, anything that might bottom out, any time... I now keep the engines lowest point a min. of 6" above ground at that bottom travel point... Just me here Build safe, enjoy the ride... PS, if you run a longer wheelbase than 96" I would go a bit higher, so as to NEVER drag the pan or flywheel... :shoot: