I'm running 15X8" with 4" BS on the Crusher with 28" slicks. Has anyone run 15X10" on a "64" and had enough clearance?
Rim Clearance Question
- Thread starter Iowa 409 Guy
- Start date
How wide of a tire are you running now?
Silversport 63
Well Known Member
You can get a 10 in there I'm running 20×10
Easy enough to calculate yourself.
Your 8" wheel is really 9" wide, so 4" backspace means you have 5" of wheel towards the fender lip. The `10" wheel is 11" wide so to keep the SAME wheel to fender lip clearance you need a 10" wheel with 6" backspace which means you will still have 5" of wheel towards the fender lip but now 6" towards the pumpkin
If you have some more room towards the fender lip then add how much you can get away with and just subtract that from the backspace.
example: You have 1" clearance with 8" wheel now so you can use an additional 1/2" towards fender lip, new 10" wheel would be
5 1/2" backspace which will now have 5 1/2" towards the fender lip
Keep in mind you also have to allow for the tire width
10.5" and it is tight against the inner fender/frame now.
Last edited:
So you have to keep same backspacing, but the 10" wheel will move you closer to the fender lip, how much clearance is there now?
Dave I use a 10” wheel and 28/10.5-15 MT stiff sidewall slick. 30” wont clear the fra m e mount or front quarter panel lip. But it a 62.
Outer fender lip probably 1.5"
The wheels I'm looking at only offer 4 or 5" BS
Using the 4" BS I may be able to use a spacer if there's enough room on the outer fender. I'll have to do some measuring.
Silversport, what tire are you running?
Last edited:
Dave are you changing tire size also or just the wheel size?
Looks like you would have to use the 5" backspace 10" wheel which should clear the outer lip by 1/2" IF it will clear on the inside with1" more backspace. Going to be tight
Just wheel size James.
I don't know how close you are on the inside but it sounds like moving the wheel out is your only option. The wheel width may not have much change in the tire bulge 
Rub marks probably from when turning short. Will have to measure that closer also.
I hope your looking at some nice light weight wheels and maybe some drive studs to go along with them. 
That cross section Steve was talking about is really all that matters. 10inch wide rim all day but if you get a fat side wall on the car then it may go way past what you have room for. Keep in mind another way to gain a larger foot print is to go with a larger diameter tire then you are currently running with the same width rim you already have. That will mean reconsidering the gearing you currently have to make up for the larger diameter tire you would then be spinning. There is a third option: The tires design itself can lead to a difference in the manner in which it creates a footprint. Some tires have a distinct shape that won't allow the side wall to lay down at all and assist in initial launch/traction. Other tires have a smooth rounded sidewall to "tread" area that does allow the sidewall to lay down more area. By simply switching from an 8 inch wide rim to a 10 inch wide rim and use the same tire, you may gain on the amount of area your tire will touch the ground side to side and front to back because when you air down to race preasure then the wider wheel will create a larger useable footprint because the same tire is being asked to hold the same weight with less help when the side wall at the rim is further out.
I'm just saying there are a number of ways to create a measurable difference but the first thing I would do is find some cheap ass 10inch wide rims that you can put your current tires on and run them down the track and see if you feel a difference and whether you see a difference in the time slip. Craigs list, Ebay, Facebook Marketplace and on here. Someone has a set of rims they may even lend you to experiment.
I'm just saying there are a number of ways to create a measurable difference but the first thing I would do is find some cheap ass 10inch wide rims that you can put your current tires on and run them down the track and see if you feel a difference and whether you see a difference in the time slip. Craigs list, Ebay, Facebook Marketplace and on here. Someone has a set of rims they may even lend you to experiment.
But that would change the foot print not just side to side but front to back when the tire is down to race pressure.I don't know how close you are on the inside but it sounds like moving the wheel out is your only option. The wheel width may not have much change in the tire bulge
Last edited:
I hope your looking at some nice light weight wheels and maybe some drive studs to go along with them.
19# wheels. There's plenty of threads on the studs.