Tire Fitment question #12,357

[stexag]

Could someone with 275s on 9.5" rims give me an idea how much the tires bulge out past the bead? I have 18x9.5 coy 57s (5.5" BS) and based on my research here I'd like to use 275/55/18 on the rear. When I bolt the wheels up I have roughly 2 fingers clearance between the inside of the wheels and the fenders. I was just wondering if the tires bulge out much or if the sidewall is pretty straight. Book says tires are 10" wide.
Posted via Mobile Device

[Portmod7]

275 is the section width in mm. Section width is defined as the overall width, outside of sidewall to outside of sidewall. There are 25.4 mm in an inch, so;

275/25.4=10.83"

A 9.5" wheel is probably 10.5" wide to the outside of the lip, so I would say your tire would bulge approximately (10.83-10.5)/2=0.165" past the edge of the wheel on each side. In between 1/8" and 3/16".

Hope that helps a little. I know it's not a measurement off an actual tire, but it's the way the numbers work out. Tires and dimensions will vary by manufacturer too. All "275" tires won't be the same.

[Fitz]

Originally Posted by stexag

Could someone with 275s on 9.5" rims give me an idea how much the tires bulge out past the bead? I have 18x9.5 coy 57s (5.5" BS) and based on my research here I'd like to use 275/55/18 on the rear. When I bolt the wheels up I have roughly 2 fingers clearance between the inside of the wheels and the fenders. I was just wondering if the tires bulge out much or if the sidewall is pretty straight. Book says tires are 10" wide.
Posted via Mobile Device

275/60R17's on 10 inch rims

[68Stepbed]

Here's a 275/55/17 on a 17x9.5 rim.

[stexag]

Man, thanks guys I really appreciate the help. It does not appear that rubbing will be a huge issue. Those tires don't appear to bulge out much and portmod's math confirms that.

Looking at those pictures now that 275 does look like a lot of tire and it has me second guessing. Ya'll ever suffer from the phenomenon "paralysis from analysis"? Ha ha. well, that's where I'm at. Don't want the rubber band look but don't want to rub on anything but the asphalt.

I've done the 3.5/5 drop and have 4 C57's here. 18x9.5 & 18x8. If I did a 255/55 on the rear what would be your suggestions for the front?

[Portmod7]

FYI, I just had some 275/40's mounted on 20x8.5" wheels. The tire manufacturer's say that's a no-go, but Discount didn't have any problem with it. My backspacing would be very close to 4.75" on the narrow 67-70 rear end. My truck is lowered 6" in the back.

I did a little test fit last night and it looks like I'll just barely clear on the outside, and I've got another 1/2" before the inside of the tire hits the bedside. So I don't see why you couldn't run a 275 tire if you get the backspace right.

I put 255/40's on the front.

[68Stepbed]

Originally Posted by stexag

Man, thanks guys I really appreciate the help. It does not appear that rubbing will be a huge issue. Those tires don't appear to bulge out much and portmod's math confirms that.

Looking at those pictures now that 275 does look like a lot of tire and it has me second guessing. Ya'll ever suffer from the phenomenon "paralysis from analysis"? Ha ha. well, that's where I'm at. Don't want the rubber band look but don't want to rub on anything but the asphalt.

I've done the 3.5/5 drop and have 4 C57's here. 18x9.5 & 18x8. If I did a 255/55 on the rear what would be your suggestions for the front?

I don't think you will like the 255/55 as a rear tire. It may not fill up the wheel well enough.

A good 18" tire combo is 255/45/18 front and 295/45/18 rear. It's still a big enough tire to not have the "rubber band look" and the sidewall won't bulge too much and rub.

Is this going on a stepside or fleetside? You may have to run a spacer on the rear wheels. My wheels have 5.5" bs and they rubbed on thie inner side, so I have 7/16" spacers on each rear wheel. I also recommend an adjustable track bar of some sort to center the rearend.

[stexag]

68stepbed - It is going on a fleetside. When you say not enough tire to fill up the wheelwell, are you talking about the tire profile or width?

[68Stepbed]

Originally Posted by stexag

68stepbed - It is going on a fleetside. When you say not enough tire to fill up the wheelwell, are you talking about the tire profile or width?

A combination of both, but mostly in width. The few trucks I've seen with that size rear tire, it just looks a bit small.

The link below shows a truck with 255/55's on all corners. I don't remember his drop. It may be mentioned in the thread.
http://tennesseeclassictruckclub.com...p=57057#p57057

[stexag]

I want to thank everyone that offered advice in this thread - you were all a big help. I eventually went with the original plan for the look I liked on other trucks I've seen on this site. I will post a picture here and provide details hoping that this thread will someday help someone like me who is scouring this site looking for that 'perfect fit' on their truck.

I have 2.5" drop spindles in the front with another 1" of spring drop for a total of 3.5 in the front. The rear is a 5" drop. Wheels are 18" C-57's, 8" (4.5" bs) in front and 9.5" (5.5"bs) in rear. Tires are Kuhmo 275/55/18 rear and 255/55/18 front. Everything fits to my satisfaction and it drives out well.

I'm happy. Thanks again.

[68Stepbed]

Nice!! Looking good! I'm glad we could help you out on your decision.