Post by Candyman on Jul 25, 2008 14:51:00 GMT -8
Hey Everyone,
I was roaming around the internet the other day, and stumbled across this, and though math is so not my strong suit, I thought this might be interesting "if someone can understand it". Anyways, check this out!
First of all, so everyone can follow along a quick lesson in terminology: The wheel is the hard round metal thing, and the tire is the softer round rubber thing.
OK, here we go...
The number following the slash is the side-wall height as a percentage of tire width.
Those of you that have the factory 195/65-15 tires:
width = 195 x .03937 (conversion factor for mm to inches) = 7.68"
side-wall height = 195 x .65 = 126.75mm x .03937 (conversion factor for mm to inches)= 4.99"
Those that have the factory 205/55-16 tires:
width = 205 x .03937 (conversion factor for mm to inches) = 8.07"
side-wall height = 205 x .55 = 112.75 x .03937 (conversion factor for mm to inches)= 4.44"
Therefore, it appears that the overall height of the 15" and 16" wheel/tire combo is very close:
2 side-walls + rim diameter = overall height.
for 15": (2 x 4.99) + 15 = 24.98"
for 16": (2 x 4.439) + 16 = 24.88"
So now you can start to plug in some numbers to see what affect (look) a particular tire size will have on your Cruiser. If you want to try and fill in the gap in the rear wheel well you can get an idea of how much a particular tire size will impact the gap. Likewise, if you are changing the front tires, you can calculate a tire size that will keep you as close as possible to one of the above numbers. Both tire values are stored in the computer's memory. So if you can hit or come real close to one of the above numbers you can rest assured that your speedometer and odometer will be accurate. Your dealer may have to reprogram the computer so it reads the other value.
Since I intend to stay with 16" wheels, I have already converted some 16" tire sizes. (BTW, if you have Excel or similar program plug the above formulas in and have a ball). Note tire width and percentage is irrespective of wheel diameter. It's just that the number following the slash will be different for other size wheels.
Tire_____________ width____________side-wall height___________overall
195/65-15 ................7.68"..................... 4.99" ................................24.98" (stock 15" tire)
205/55-16 ..............8.07 ...................... 4.44 ..................................24.88 (stock 16" tire)
215..........................8.46 ......................
225/50-1 ................8.86 ...................... 4.43 ..................................24.86 (good front and/or rear match)
235 .........................9.25
245/45-16...............9.65.........................4.34 ..................................24.68 (this is shorter than stock,> gap)
245/50-16 ..............9.65 ........................4.82 ..................................25.65 (bigger than stock,
255/45-16 ............10.04 ....................... 4.52 ..................................25.04 (slightly bigger, too wide I'm told)
255/50-16 ............10.04 ........................5.02 ..................................26.04 (too wide I'm told)
Keep in mind that the amount of gap between tire and fender is only the difference in side-wall height, not the difference in overall diameter. So subtract the non-stock tire side-wall height from the stock side-wall height to see how much you're reducing the gap.
Man, my head hurts now!
Take it easy!
Candyman
I was roaming around the internet the other day, and stumbled across this, and though math is so not my strong suit, I thought this might be interesting "if someone can understand it". Anyways, check this out!
First of all, so everyone can follow along a quick lesson in terminology: The wheel is the hard round metal thing, and the tire is the softer round rubber thing.
OK, here we go...
The number following the slash is the side-wall height as a percentage of tire width.
Those of you that have the factory 195/65-15 tires:
width = 195 x .03937 (conversion factor for mm to inches) = 7.68"
side-wall height = 195 x .65 = 126.75mm x .03937 (conversion factor for mm to inches)= 4.99"
Those that have the factory 205/55-16 tires:
width = 205 x .03937 (conversion factor for mm to inches) = 8.07"
side-wall height = 205 x .55 = 112.75 x .03937 (conversion factor for mm to inches)= 4.44"
Therefore, it appears that the overall height of the 15" and 16" wheel/tire combo is very close:
2 side-walls + rim diameter = overall height.
for 15": (2 x 4.99) + 15 = 24.98"
for 16": (2 x 4.439) + 16 = 24.88"
So now you can start to plug in some numbers to see what affect (look) a particular tire size will have on your Cruiser. If you want to try and fill in the gap in the rear wheel well you can get an idea of how much a particular tire size will impact the gap. Likewise, if you are changing the front tires, you can calculate a tire size that will keep you as close as possible to one of the above numbers. Both tire values are stored in the computer's memory. So if you can hit or come real close to one of the above numbers you can rest assured that your speedometer and odometer will be accurate. Your dealer may have to reprogram the computer so it reads the other value.
Since I intend to stay with 16" wheels, I have already converted some 16" tire sizes. (BTW, if you have Excel or similar program plug the above formulas in and have a ball). Note tire width and percentage is irrespective of wheel diameter. It's just that the number following the slash will be different for other size wheels.
Tire_____________ width____________side-wall height___________overall
195/65-15 ................7.68"..................... 4.99" ................................24.98" (stock 15" tire)
205/55-16 ..............8.07 ...................... 4.44 ..................................24.88 (stock 16" tire)
215..........................8.46 ......................
225/50-1 ................8.86 ...................... 4.43 ..................................24.86 (good front and/or rear match)
235 .........................9.25
245/45-16...............9.65.........................4.34 ..................................24.68 (this is shorter than stock,> gap)
245/50-16 ..............9.65 ........................4.82 ..................................25.65 (bigger than stock,
255/45-16 ............10.04 ....................... 4.52 ..................................25.04 (slightly bigger, too wide I'm told)
255/50-16 ............10.04 ........................5.02 ..................................26.04 (too wide I'm told)
Keep in mind that the amount of gap between tire and fender is only the difference in side-wall height, not the difference in overall diameter. So subtract the non-stock tire side-wall height from the stock side-wall height to see how much you're reducing the gap.
Man, my head hurts now!
Take it easy!Candyman
