I don't own one (yet) and dont' really wear one going for a chilled ride by my self. as soon as I get with other riders and the bar is raised, I'm trying new things then i'll borrow my mates. I still feel like a tw*t wearing the typical MTB lids. need to get me a piss pot. the only time i needed a helmet (and was wearing one), i flipped my bike and landed on my sholder/head on the edge of a curb, the helmet i was wearing, cracked, split and impailed the back of my neck. it was a Met.........something from Halfords. if any trials rider should wear one, it should protect the bk of you head/neck. but then again if you doing low risk manuvers your more likely to shin-dig. I (almost) never ride with out my 661 shinnies.