Wow, I feel lucky. I've always had long hair and none of the troubles/aggravation I read here. Maybe I just have a high tolerance for snarls, etc?! Years ago, prior to a helmet, it was just a headband on my free hair.
Now I have a helmet, last year it was one pony down the back, tied below helmet. Year before I did two ponies, tied below helmet. No problem with velcro, and I guess it doesn't bother me when it's all over the place and comes out above my collar. Although this weekend the ponytail holder was stretched, and kept loosening up, so I just took it off. By then my hair was well set into the helmet and didn't bug me at all. I don't like having it next to my skin though - like under my neck gaitor or collar. The fine hair under my pony might get a little snarly, but that's it, nothing at the top or anything. I actually prefer my hair longer in the winter b/c it's easier, often get it cut shorter in the spring.