The flywheel adapter was made out of a scrap of 6061 aluminum that was laying around the shop. I to am worried about it not being strong enough but I'm working on setting up a stress analysis in Autodesk inventor and I'll talk to my dynamics and strength of materials teachers about doing the calculations by hand in order to check myself. If it isn't strong enough I'll make a new one (this one was free), but thinking about it it really should be fine; there is no way the 6 M10x1.00 bolts will pull out and the clutch will slip before it shears the bolts or their holes deform. 6061 is actually pretty strong though so the only thing I'm worried about is it fatigue cracking (7075 really would be better in this application) but the the cycle life is also calculatable.The rest of the adapter will be 6061 and definitely is will be strong enough.