Beadlock back space?

How do you measure the back spacing on a beadlock wheel. I have a set of weld beadlocks that i'm using for mock up. The guy I got them from told me that they were 4in BS. I measure 4 1/2 to the edge of the parting line and over 5" to the outside of the lock ring. Where should I be measuring to?

 

According to Weld Wheels, on double bead locks, it is measured from the outside edge of the bead lock ring to the inner mounting flange, here is a link to their PDF that shows how to measure.

 

100% correct... Thats the way to measure beadlocs....

 

Sweet.

Thanks for the info. That means i have more tire clearance than I thought...

 

Just remember that more backspace places the wheel & tire closer to the chassis.

 

Ya. Thanks. I am using a set of wheel for mock up and thought they were 4" bs but are really 5" so if I find a set of 4.5" or 4" bs, I will have lots of room.
Thanks again for the info. Love ITA.

 

???

i know thats how weld told me to measure too, but i had a set of older welds(sold them), i cant remember the thickness of the beadlock flange off hand(have it written down somewhere), but i know that another set of wheels i had looked at (used) had a thinner ring. that being said, if you measured that way you'd have 2 different backspacing measurements but in reality it would put the tire at the exact same spot. does this make sense or am i overthinking it? i know thats how they measure them, but i'd think a more accurate way would be to measure to the lip where the ring bolts to allowing for different thickness rings. just a thought so i'd have to measure the rings before i buy a new set or different manufacturer!

 

I agree, it would be more consistent and more accurate to measure to the parting line, but, I don't think a 1/4" to 1/2" difference would have that much effect.

It looks like the method shown is just an easy way to measure, straight edge and yard stick.

 

The tire bulge makes more of a difference when it comes to chassis interference. You need to have that measurement in addition to the backspace to keep you out of trouble.

 

weld me

heres a link to welds catalog . look at page 47 on spacing measuring.dan http://www.weldracing.com/pdf/weld_catalog.pdf