Bark busters are purpose built........read name "bark busters" so they're not for everyone,but if you do tree hugging like I do from time to time then they're great. I have heard many horror "stories" about broken wrists from bark busters, but never seen or known someone have it happen. I think they're perfectly safe. And they are legal for mx, back in 94' Before "mx" handguards were available Mike Kiedrowski ran them at Unadilla after returning from a broken finger. I do agree that the mx-style are more purpose built,but the tips about the sliding the levers closer to the center of the bars is a good common rule. If your willing to spend around 50-60 dollars on the bark busters/mx guards, I would look into buying the ASV levers. They're designed w/a hinge in the grip that allows the lever to bend backwards on that axis and is warrantied for 3yrs! They are expensive at 60 bucks per lever, but if you have that much of a problem w/levers you've probably spent more than that replacing levers. Although the best option is just to stop crashing so much;)