this is plain old status interplay, practiced by adolescent males world wide and in a manner practiced by primates for millions of years. To be honest, it's an ancient genetic predisposition towards a group behavior meant to pick off older, weaker low status males ultimately removing them from the gene pool and making for less competition for diminished resources.

Keep your gaze forward, your head still, keep your eyes narrowed or better yet wear dark intimidating sunglasses, which do not reveal your eyes (do not bug your eyes or let them appear too large). Ride in a straight line with purpose as if you expect those low status juveniles to move out of your way. If you do make eye contact hold it, especially with the largest most dominant one in the group if you wish to assert your dominance or challenge them. Though ignoring them all, as if they weren't even there, rather than singling any individual out as even worth the trouble to challenge is even more dismissive and high status. If necessary, a deep guttural and well timed "Coming through!" will add to your dominance. Get some balls and own the road.

ps and get some mace.

No, that would just amplify the situation.

If I was a kid and had that good for nothing attitude and felt like not giving you the right away.

You could:

beat me in my own game and make me chicken out by running right at me because I dont want to get hurt or have my bike broken.

scare me with the athorities if I was doing somthing that could be deemed illegal

get my parents invovled (follow one of them home one day, or totally stop them all together and be like what the hell! then eather settle it there or let them know if it happens again your going to speak to there parents)

I was never a bad kid I was a "angel" but my brother was.

If you did somthing to him like a revenge game he and his friends would just get you back 10x worse, and they are the ones under 18... they can pretty much get away with murder, while you can get the handcuffs slaped on or a ruined record over nothing if they play there cards right, esp if they get there parents involved at you, instead of the other way around.

Personaly myself I would have no problems I am a genuinly very intimidating person by nature and a group of kids wouldnt bother me. The worse side of things like older kids and gangs could pose a threat but those are the people that usually do illegal things like carry firearms and the athorities could take care of that.