TeamRX8

iTrader: (2)

huh, could have sworn I made a post in here yesterday

any way, technically if a 10” +50 is a known inboard limit then the equivalent to that is 11” +37 because 1/2 of the width increase needs to be accounted in the offset to maintain the same backspace dimension

otherwise if an 11” +50 fits then that suggests that a 10” +63 will fit, which is quite different than the established standard

so even if it was 10” +51, somebody’s numbers still aren’t matching up. Titan changed the 18x10.5 +50 FD3 wheel application to 18x10.0 +50 because there were issues with interference on one of the rear arms. Another 1/2” width to 11” is another 6.35mm/0.25” further inward on the inboard wheel lip.

in this case being rear wheel only maybe the one arm has possibly been offset or modified (edit: this is the difference per the reply below)? Otherwise it seems like 11” +50 on the front would also need the steering modified to decrease full lock to keep the tires from rubbing at extreme steering angle. Not saying 11” +50 won’t work, but it seems to go against the long established standard by quite a bit. If anything I’m wondering if a mistake was possibly made.

Because the offset standard is based on the wheel bead seat position, but backspace is to the outer wheel lip position. Some people may not understand that wheel industry standard for bead seat to outer lip width is 1/2”, or 12.7mm. In other words, a 7.5” backspace translates to a 7” inboard tire bead seat postion.

So a 10” wheel is the width between the bead seats, but it’s 11” wide across the outer wheel lips. The amount that an 11” +50 might be mistakenly listed as when it would actually be the expected 11” +37 if that 1/2” difference between bead seat and wheel lip wasn’t accounted for properly. Not saying it is mistaken, just wondering how there could be such a large discrepancy in these numbers and that could be one possibility.

an 11” +50 should have a 7.97” backspace (backspace = 1/2 wheel width between the tire bead seats + offset + std. 1/2” wheel lip width OR backspace = 1/2 wheel width across the outer wheel lips + offset)
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dk_davis

To help with my contribution. My fitment requires aftermarket trailing arms and the mounting point must be modified to allow maximum inward mounting. Even then the clearance is so minimum that the flex of the tire during high-g cornering will allow the tire to slightly rub the trailing arm. Another factor that comes into play when you choose to maximize your available space is simple things like new brake rotors affect things. My current set is slightly thinner than the prior and I have recently starting running a 3mm spacer to help compensate.

TeamRX8

iTrader: (2)

seems like an important point, so thank you very much for the clarification.

are you only running those on the rear then?
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dk_davis

Yes, 275s on 9.5 wheels up front.

James2u

iTrader: (5)

Yes, I am running 18x11 CCW Classics with Hoosiers A7 315s square set-up. The wheels have 7.5" backspacing. Front fenders have been English rolled and the rears are rolled.