Trouble w/rally rim

[firebob]

Had a full set of 15x8 chev rallys that my race tires have been mounted on. One of the rims has gone bad so I am on a search for a replacement. I always thought these were 4" BS but I measured the reamaining three the other day and they look to be 3 1/2" BS. I was given a brand new Wheel Vintiques "hot rod style" rim that I thought I could use but it turns out to be 4 1/2"BS. ARRGH, the saga continues...

Robert

[MrQuick]

do you need one or are you venting? put an add up in the wanted section. Also, where are you from?

[brownz]

I will check the two ralleys that i have with slicks and will get back to you if the b/s is what you need

[firebob]

Yes, I do indeed need one.
Now I hope I'm measuring the backspacing correctly. I laid a straight edge on the flat part that the tire bead is against and then measured down to the mounting surface of the center.
I'm in NorCal. Near Berkeley.
Brownz thanks for checking/

Robert

[MrQuick]

All the ones I have are 5". make sure its a 15x8. doesn't sound right.

[Boesch]

See this page on how to measure backspace and rim width:

https://rsracing.com/tech-wheel.html

Note that the rim width is not how wide the rim is, but rather from bead seat to bead seat. A lot of people mistake this measurement.

[firebob]

According to the diagram on the website I'm measuring wrong. It says to lay a straight edge across the outer edge of the rim and measure down to the center. I always thought you measured from the flat part inside the lip(bead sealing surface). At any rate it just adds about a 1/4" to my measurements.

http://im1.shutterfly.com/procserv/47b8df29b3127cceb330b5a4a5c300000026108BcNW7ly0b8
http://im1.shutterfly.com/procserv/47b8df29b3127cceb330b517244000000026108BcNW7ly0b8
http://im1.shutterfly.com/procserv/47b8df29b3127cceb330b5f6a59100000026108BcNW7ly0b8

Measuring the other way I get about 4" on the stock rim and about 4 !/2" on the aftermarket.

Robert