any suggestions?

 yea if there was an actual hill or cliff instead of just flat lines it would be waaaaay betttter

 faded hill/cliff blue on black

 I like the idea, but I dont think the shirt makes as much sense as it could. You have 2 different styles of riding. If you have the guy 360ing specifically depicted on the shirt, then maybe the work harder part should be a guy building a massive drop or jump to 360. Or for the other "genre" of riding, the XC rider should be riding up hill (working hard), reaches the peak and (plays harder) ripping down some sick single track. I hope you know what I mean. Not saying my idea is 'right' just a personal opinion. I love the idea man.

 thnaks guys i was just testing this out for suggestions thanks i'll try and get all your ideas into a new shirt

 any suggestions for a new slogan?

 maybe just 2 words or something, but logos and pictures/patterns strike me as better than catchy phrases.
i don;t have any awesome ideas but just trying to give constructive criticism.