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      01-10-2011, 06:39 AM   #6
No 55mph
1QuikWS6's Avatar

Drives: F32 435ix MSport ->M6
Join Date: Jul 2009
Location: Blitzburgh, PA

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2016 BMW 435ix  [0.00]
Have they ever done an FEA Analysis of the slotted areas with the integral thru holes to see anticipated stress and breaking point at the very thin web that is left?

I understand the concept and the reason for this design, but in the case of just slots alone - the slots may be 1/16" deep out of the total 1/4" thich rotor surface, or in the case of thru holes alone, you still have the total 1/4" thickness - weak point would be between the holes.

But with this design, you have the depth of the slots (which looks to be more than 1/16") and then they drill out the web thickness that is leftover even more with the thru holes - resulting in a very thin web that is actually left between the holes at the bottom of the slot.

These areas will be very prone to cracking in the thin web area between the thru holes in the slots. You may get away with it on street only brakes - but I wouldn't use them for continous hard track use without having the results of the FEA prove a safety factor of at least '4'

I also understand the concept behind the centrally located hat mounting tabs - so that you can switch the directional rotors side for side - but why would you want to?

Only reason I can think of is if say you had a damaged right rotor - you could swap over the left rotor and only need to buy (1) replacement rotor - but normal practice is to replace rotors in pairs...

Not tryin to bash their design - just throwin some observations out there.
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Last edited by 1QuikWS6; 01-10-2011 at 07:08 AM.