Originally Posted by Big Windy
thanks, tom. i see what you are saying, but there still is no absolute data. for instance, what evidence do you rely on to know that over 20mm is bad?
Turning the tables a bit - there's no evidence to show that over 20mm is perfectly safe either. It's a a decision that is yours to make.
To answer your question - Zero. However its not a risk we're up and willing to take, as you're close to doubling the stock shank length.
On another note, H&R offers a particularly wide spacer (30mm) for X5s which allow the lugs to thread into the spacer itself (DRA Series), and no reports of damage since the models were introduced back in 2000, clocking quite a bit of miles to date.