Hey, I'm somewhat new to the forum and and i'm looking for a biking helmet in the size of a 23.I'm also looking for a good U lock so I'll be able to lock my investment, otherwise my 2008 Avalanche 3.0 disc.Help me decide on a lock and a helmet, I also don't mind what kind of helmet but It should be less than 40$.

PS.-What does it mean to bottom out and top out when it comes to suspension

Thanks