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-   -   Cragar rims back spacing and rear tire width (https://67-72chevytrucks.com/vboard/showthread.php?t=586720)

Geos 72 06-29-2013 01:19 PM

Cragar rims back spacing and rear tire width
 
Hello to everyone, sooner or later I want to put a set of 15x10 Cragar rims on the rear of my 72 Chevy Cheyenne C10 w/ a set of tires to fit the width of the rims. I don't want the tires to stick out past the wheel wells. I wonder if anyone would know what back spacing would the rims have to be and what width the tires would I need to have it all tucked under the box. I hope I'm explaining that right. Any help would be appreciated. Thank you, George

70_step 06-29-2013 05:36 PM

Re: Cragar rims back spacing and rear tire width
 
Is your truck a fleet side or a step side? I'm running 295/50's on my 15x10 cragar's.

Geos 72 06-30-2013 12:32 PM

Re: Cragar rims back spacing and rear tire width
 
I forgot to put that in, sorry about that. My truck is a step side. Thanks.

Geos 72 06-30-2013 12:33 PM

Re: Cragar rims back spacing and rear tire width
 
SORRY, I meant to say Fleetside. It's a Fleetside. Thanks.

Geos 72 07-08-2013 10:36 PM

Re: Cragar rims back spacing and rear tire width
 
Hello to everyone, I'm still looking for someone to help me with my question. Someone out there has to know, please help. Thanks.

geezer#99 07-08-2013 11:42 PM

Re: Cragar rims back spacing and rear tire width
 
What cragar rims?
Most aren't custom made and come in a standard backspace. Once you know the backspace you can measure on your truck to see how they fit. You don't even need rims, just a straightedge and a tape measure.

Geos 72 07-09-2013 06:20 AM

Re: Cragar rims back spacing and rear tire width
 
15x10 Cragar rims. I didn't know they came in a standard backspace, I thought they came in different measurements. It's been a very long time since I bought a set and I just wasn't sure. Thank you for your reply, I appreciate it.

CC69Rat 07-09-2013 08:12 AM

Re: Cragar rims back spacing and rear tire width
 
5.5 " Backspacing would fit nicely.

Most of the guys that run 20's on these trucks run a 10" wheel with 5.5" BS on the later rear end housing.

a 295 tire is going to be 11.61" wide. 295 / 25.4 = the width of the tire in inches.
the next number will be the aspect ratio of the tire. So above the guys mention a 50 series tire.. or 295/50/15.

Take your width -- 295/25.4 and multiply times your aspect ratio. (295/25.4)*.50 = 5.81"

This gives you the height of the sidewall in inches. So we know we have a sidewall on the top of the tire and the bottom of the tire. 5.81*2+15 (<~~ your wheel) = the overall height of the tire itself.

(295/25.4)*.50 * 2 + 15 = roughly 26.75" tall. It all really depends on how the truck is lowered (if any) and how you want the tire to fit in the wheel well. Do you want it to tuck under the fender, .. sit flush with the fender, etc. 275/60/15 10.82" wide and 6.49" sidewall, 28" tall.

Just for reference a 295/40/20 will tuck under a fleetside with 5.5" Backspacing. BUT, remember the 40 series tire will not have as much section width.. (the balloon effect of the sidewalls because they are shorter obviously) a 295/50/15 will look more 'puffy' than a 295/40/20.

Not assuming you don't know any of this, .. just trying to help.
Later.

Geos 72 07-09-2013 08:36 AM

Re: Cragar rims back spacing and rear tire width
 
WOW, that was the most information I got in two weeks and I thank you very much. I'm really not very good with figures like that but I do understand some of it. My truck hasn't been lowered and I do want the tires tucked under so a 5.5" backspacing would fit nicely but I'm still not sure with what size tire. Thank you for all your help, I appreciate it very much.

geezer#99 07-09-2013 08:58 AM

Re: Cragar rims back spacing and rear tire width
 
Rule of thumb for width of tire on a rim is add 1" to the rim width.
A 10" wide rim will be 11" wide. The width of the rim is to the bead not to the rim edge. Most tires I add 1" to that so you have a total width of 12". Subtract your backspace which might be 4" and the outer edge of your tire would be 8" from the mounting surface.
Put a straightedge on the hub and use a tape measure to measure from it to any interference points on your fenders. Just remember most inner wheelwells curve inward right away so depending on tire height you need to measure up inside to. Also remember you need clearance for tire movement. Add another 1" on both sides.
Here's a link to cragar. Click on specs and a pdf will come up with all the info you need.
http://www.cragarwheel.com/products1...61SSSuperSport

CC69Rat 07-09-2013 09:17 AM

Re: Cragar rims back spacing and rear tire width
 
Here's a couple pics of a 275/60/15 on an 8 (some 10's)

I'd do 8" wheels and 275/60s .. that way if you had any future plans for lowering it (?) it would still tuck under the wheels wells without rubbing issues. (just me)

http://67-72chevytrucks.com/vboard/s...d.php?t=286762

I have never seen your truck, not saying it would look bad either way. BFG / Silvertown 285/70/15 looks sick on an 8" wheel, especially if the truck is dropped a little. But they are MEATY. Looks killer on a low and lean Big Block truck though. .. :metal:

http://67-72chevytrucks.com/vboard/s...d.php?t=368862 <~ post #14

Just my personal tastes, I think if you're doing 20's, go with a 10" wheel. If you're doing less than 20's .. go with a narrower wheel. 18's, do 9.5" wheels. 17's, do 8.5-9" wheels.. etc. 15's, I'd do 8" wheels.. just sayin. :D

Geos 72 07-10-2013 11:21 AM

Re: Cragar rims back spacing and rear tire width
 
70 step, geezer#99 and cc69 Rat thank you so much for all your help, I really appreciate it. Geezer#99, I thank you for all your info and the web site to Cragar. CC69 Rat, I thank you for all your information and pictures which I really enjoyed looking at, they were great. All the info I got from all of you will be a great help when the time comes. Again, I thank all of you.

70_step 07-11-2013 06:14 PM

Re: Cragar rims back spacing and rear tire width
 
No Problem, as cc69rat said a 275/60 tire on a 15x8 looks really nice as well. thats what i used to run and personally i think it looks cleaner. but i got a free set of cragar ss wheels that are nicer than what i used to run. if you want i can add pics of before and after

Geos 72 07-11-2013 07:26 PM

Re: Cragar rims back spacing and rear tire width
 
70 step, that would be great. I always like looking and see what things look like. Thank you very much.

70_step 07-12-2013 05:05 PM

Re: Cragar rims back spacing and rear tire width
 
4 Attachment(s)
The first two are with stock springs in the rear and cut coils in the front. The last two are with a 5" drop in back same set up in the front. 15x8's all the way around with a 275/60 on the rear and a 215/70 on the front.

70_step 07-12-2013 05:09 PM

Re: Cragar rims back spacing and rear tire width
 
3 Attachment(s)
Here it is with the cut coils in the front and a 5" drop spring in the rear. 255/60 on a 15x7 or 8 (not sure) on the front and 295/50 on a 15x10 in the rear.

Geos 72 07-15-2013 09:08 AM

Re: Cragar rims back spacing and rear tire width
 
Hi 70 Step, sorry it took so long for my reply. Thank you for the pics. I really like the Cragars, they look so much better than the other set. The rear looks great. Looks like the right combination and the tires don't seem to be sticking out of the wheel well. I just wonder if that set up would work on a Fleetside? Thanks 70 Step, I sure appreciate everything. George

70_step 07-15-2013 05:51 PM

Re: Cragar rims back spacing and rear tire width
 
I would imagine it would. Here is a link that explains how to measure for wheels, http://www.powerblocktv.com/two-minu...heel-clearance

Geos 72 07-16-2013 09:02 PM

Re: Cragar rims back spacing and rear tire width
 
70 step, I was looking for 295/50/15 on ebay. I found a nice new set for $374 for two. It also said the tires are 12.2" wide. I went out and measured under the box and they won't fit unless they stick out and I didn't want that. I guess I'll either have to make the box wheel wells wider or just forget the 15x10's. It's always something, ain't it?

Geos 72 07-16-2013 09:34 PM

Re: Cragar rims back spacing and rear tire width
 
Well the first set I looked at was BF Goodrich tires so I just looked at a set like you have. It said they are a little over 11 3/4" wide. I'll go out tomorrow and see what that looks like. Have a great night.


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