Custom wheel, OEM backspacing?
08-29-2010, 07:04 PM
#1
Custom wheel, OEM backspacing? Just curious, when ordering a custom wheel, is there any reason (for a Trans Am) to order something other than the 7" backspacing/50mm offset for the front and rear?
Going to be picking up a set of Billet Specialties 17" RTs over the winter, and just want to make sure I get the numbers right.
Going to be picking up a set of Billet Specialties 17" RTs over the winter, and just want to make sure I get the numbers right.
08-31-2010, 12:52 PM
#5
About a +45mm offset for the 17 x 11's in the rear, and a +45 to +38mm offset for the 17 x9.5's up front.
17 x 11's: 7.75" BS .
17 x 9.5's: 6.75" BS(+38), or 7" BS(+45) .
For BS you need to know the overall wheel width, I figured it as 1" wider then the stated wheel size, this is an average, your's might be more or less.
12" for the 11" wheels , and 10.5" for the 9.5" wheels. So unless you know the overall wheel widths go by the offset numbers , not the BS numbers.
17 x 11's: 7.75" BS .
17 x 9.5's: 6.75" BS(+38), or 7" BS(+45) .
For BS you need to know the overall wheel width, I figured it as 1" wider then the stated wheel size, this is an average, your's might be more or less.
12" for the 11" wheels , and 10.5" for the 9.5" wheels. So unless you know the overall wheel widths go by the offset numbers , not the BS numbers.
08-31-2010, 01:40 PM
#6
Ok...wasn't quite sure if the numbers in the sticky were more of a "These wheels come with x, xx, and xxx offset, use xx for best results" sort of thing, or if they were pretty much spot-on.
Stupid question since I've never ordered wheels before, but if I know the offset I want, do I just call the manufacturer up and say, "17x11s for a '99 Trans Am, +45mm offset." and they take care of the backspacing conversion and everything else required?
Stupid question since I've never ordered wheels before, but if I know the offset I want, do I just call the manufacturer up and say, "17x11s for a '99 Trans Am, +45mm offset." and they take care of the backspacing conversion and everything else required?
08-31-2010, 02:13 PM
#7
Ok...wasn't quite sure if the numbers in the sticky were more of a "These wheels come with x, xx, and xxx offset, use xx for best results" sort of thing, or if they were pretty much spot-on.
Stupid question since I've never ordered wheels before, but if I know the offset I want, do I just call the manufacturer up and say, "17x11s for a '99 Trans Am, +45mm offset." and they take care of the backspacing conversion and everything else required?
Stupid question since I've never ordered wheels before, but if I know the offset I want, do I just call the manufacturer up and say, "17x11s for a '99 Trans Am, +45mm offset." and they take care of the backspacing conversion and everything else required?
Also find out what BS they offer, and if possible what there overall wheel widths are for the 17 x 9.5's and 17 x 11's. The post it up here, then I could give you a accurate BS numbers.
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08-31-2010, 02:35 PM
#8
You'll need to find out what offsets they offer, if they don't offer those exact offsets, then get it a close as you can with what they offer.
Also find out what BS they offer, and if possible what there overall wheel widths are for the 17 x 9.5's and 17 x 11's. The post it up here, then I could give you a accurate BS numbers.
Also find out what BS they offer, and if possible what there overall wheel widths are for the 17 x 9.5's and 17 x 11's. The post it up here, then I could give you a accurate BS numbers.
08-31-2010, 02:59 PM
#9
They don't call out specific offsets; rather, a range of backspacing offered for each wheel. Their page is somewhat short on info (the linked catalog page doesn't even show the RTs in anything other than 15" sizes) and only lists the wheels as 17x9.5/17x11, with available backspacing of 3.5" to 7.25" and 3.5" to 8.5", respectively.
