Narrowed 8 3/4 questions

rbkt65 said

Got this from Oldkimmer a few years ago and may have seen 72bluNblu post it once. turn backing plate on axle side on flat table. knot on bp has to hang off table. measure from table to center hole. measurements as follows.
1 1/2 inches are 11x2
1 3/4 inches is 11x2 1/2
2 inches is 11x3
thinking 72bluNblu said 11 bp are 12 inches in diameter and 10 inch bp are 10 7/8 diameter.

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Those are the same measurements I linked in the other thread earlier. I’ve been posting those measurements for over 10 years now.

The backing plates themselves are ~1” larger in diameter than the brake diameter, so 11” brakes have ~12” diameter backing plates (outside to outside on the plate), 10” brakes have ~11” backing plates. But of course the drums are stamped with their minimum diameter so if you have the drums it’s easy to tell what diameter brakes you have.