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      11-09-2012, 09:27 PM   #21
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Drives: E92 M3,R56 S,F22 240iX,F82 M4
Join Date: Jun 2009
Location: EC

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Originally Posted by bigjae1976 View Post
Lol...anytime! Still, my apex and OEM wheels have a taper on the back, appears to be at least 3mm. So is 2mm of engagement fine? I'm not an engineer but I know enough to make me dangerous.
2 mm = ~80 mil...In actually, the shear load is only transferred over a very short distance (i.e., the entire hub length is not effective; the spacer acts like a non-structural "gap" which increases the bending stress at the hub root). The minimum distance required for the shear load to transfer from the wheel to hub, as a quick sizing rule-of-thumb, is when the effective bearing stress is equal to the bearing yield strength of the material. If you are afraid of 2 mm of lip engagement to transfer < 2-2.5k lbf then you don't want me to get started on the structural design (static, dynamic, fatigue and fracture) of aircraft and spacecraft