I'm about to pull the trigger on a set of custom wheels and want to confirm backspacing and center bore for hub centric ring on a 1974 car. I will be running fat 205/50/15 Hoosiers on the wheels.
I will be having 15x7" wheels made with 4 lug 4x130mm bolt pattern.
Back spacing specs: I have heard everything from 4.25" to 5" for backspacing for 15x7 wheels. I'm not afraid of bending my fenders a bit to make things fit and I like the idea of a little wider track. Would 4 1/2" back spacing be enough for somone who has rolled fenders? I have lots of room now with rolled fenders and my 205/50/15 tires on 5.5" Fuchs - easily 2 to 3 inches
I do have centering ring on my front hub. Mueller provided dimensions of 78.60 mm x 15 mm which looks about right using my tape measurer. If I make an error I want to make sure its making this bore too big.
I appreciate everyones feedback.
I'll be watching for the answer, as well.
What do the rims look like? I may want to piggyback on the order
KT
All cars are a little different, so there isn't a single right answer. But the general rule of thumb on 7" wide wheels, is that a 5.00" backspace will very closely center the wheel between the inner wheel well and fenders which have been rolled and/or tugged out a bit.
The right thing to do is to take measurements on your current wheel/tire combo. measure the clearance between the tire and inner wheel well (hard to do), and the clearance between the tire and fender. Do this on both sides of the car as they will be different. From there, some simple math will tell you the proper backspace or offset you will require to center the wheel between the inner and outer fenders (if you have 4 bolt Fuchs, your current backspace is about 4.7" - you will need this info in your calculation). There won't be much room for error, but you will want to err on the side of having the wheels closer to the outer fenders than the inner fenders (a little less backspace) because it is much easier to massage the outer fenders to get the wheel/tire combo to fit. The inner fenders or wheelwells will be much more difficult.
Demick
I've had 2 sets of 15 x 7 Revolutions with 5" BS. The spacing was just about perfect. I did have to roll the lip in one side only.
Go with 5" BS.
Paul
QUOTE (trekkor @ May 25 2005, 06:21 AM) |
I'll be watching for the answer, as well. What do the rims look like? I may want to piggyback on the order KT |
QUOTE (Demick @ May 25 2005, 06:44 AM) |
All cars are a little different, so there isn't a single right answer. But the general rule of thumb on 7" wide wheels, is that a 5.00" backspace will very closely center the wheel between the inner wheel well and fenders which have been rolled and/or tugged out a bit. The right thing to do is to take measurements on your current wheel/tire combo. measure the clearance between the tire and inner wheel well (hard to do), and the clearance between the tire and fender. Do this on both sides of the car as they will be different. From there, some simple math will tell you the proper backspace or offset you will require to center the wheel between the inner and outer fenders (if you have 4 bolt Fuchs, your current backspace is about 4.7" - you will need this info in your calculation). There won't be much room for error, but you will want to err on the side of having the wheels closer to the outer fenders than the inner fenders (a little less backspace) because it is much easier to massage the outer fenders to get the wheel/tire combo to fit. The inner fenders or wheelwells will be much more difficult. Demick |
QUOTE (URY914 @ May 25 2005, 10:21 AM) |
I've had 2 sets of 15 x 7 Revolutions with 5" BS. The spacing was just about perfect. I did have to roll the lip in one side only. Go with 5" BS. Paul |
QUOTE (grantsfo @ May 25 2005, 08:59 AM) |
Thanks Demick, So looking at my car currently (205/50/15 Yoko's mounted on 2.0 Fuchs) I have about an inch of clearnce on the inside and about 1 1/2" of clearence on the outside fender. If the Fuch 2.0 wheels have 4.7" of spacing I may need to keep that or even go for less? So maybe 4 1/2 backspacing if I'm not shy about pulling on my fenders? |
QUOTE (Demick @ May 25 2005, 09:44 AM) |
But like I said, you need to carefully measure. 1.5" sounds like an awful lot. Remember, the place your tire will touch the fender is not at the center point of the wheel well opening - it is toward the rear of the car - so be sure and measure for the minimum clearance you find. Demick |
15 x 7 Cookie or Fuchs have back spacing of 120mm (4.725") and will/may not fit standard bodywork. Min backspacing required is 125mm (4.92") to fit without any dramas. I had my first set made with 135mm (5.31") because I wasn't sure how everything would work out and run spacers to put the wheel where I want it.
QUOTE (don9146 @ May 25 2005, 08:46 AM) | ||
I've heard that the Revolution wheels were a little on the heavy side. Just surprised they were on the lightest 914 on the planet if that is the case... |
My Panasports have a 4 and 7/8" backspacing I think... Had to massage the fender lip a bit, but not by much
here's a pic. The rear has since been lowered
Attached image(s)
Hmm, IIRC my 15x7 cookies are like 4 5/8" and the correct backspacing is the 4 7/8. Whatever the RSR wheels is correct.
Attached thumbnail(s)
Grant,
as long as I get it back in timely manner, you can test fit one of my wheels.....17x7 with a 205/45...if you are going to the breakfast, and bring your car, we can test fit it right there.....
47mm offset as is, but I can also bring you a 1/2" spacer that brings the offset to 34.3mm (normal revolutions are 35mm offset)
4x130mm bolt pattern
QUOTE (Mueller @ May 25 2005, 09:52 PM) |
Grant, as long as I get it back in timely manner, you can test fit one of my wheels.....17x7 with a 205/45...if you are going to the breakfast, and bring your car, we can test fit it right there..... 47mm offset as is, but I can also bring you a 1/2" spacer that brings the offset to 34.3mm (normal revolutions are 35mm offset) 4x130mm bolt pattern |
I forgot, I also have one 15x7 steel wheel (no tire) that fits under the stock fenders (it's one of the rims that Jenny has on her car now).....this way you could mount the specific tire you have in mind to get a better fitment idea......
QUOTE (URY914 @ May 25 2005, 07:21 AM) |
I've had 2 sets of 15 x 7 Revolutions with 5" BS. The spacing was just about perfect. I did have to roll the lip in one side only. Go with 5" BS. Paul |
Thanks for everyones input. I have ordered custom 15x7 wheels with 5" back spacing.
Cool
What do they look like and how much are they?
KT
QUOTE (trekkor @ May 26 2005, 05:34 PM) |
Cool What do they look like and how much are they? KT |
Wow, Grant
Kinda expensive. Nice though.
I look foward to seeing them on the car.
Gonna do any freaky race car paint work. I might.
Thanks for pioneering this.
KT
QUOTE (trekkor @ May 26 2005, 07:14 PM) |
Wow, Grant Kinda expensive. Nice though. I look foward to seeing them on the car. Gonna do any freaky race car paint work. I might. Thanks for pioneering this. KT |
very cool grant
my 'phase II' plans for the car might involve custom wheels .... nice to see how these will work. 1300 really ain't bad. and <11 lbs!! damn!!
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