I have a Sora Front Derailer, brand new, and just today it refused to go "up" to the big crank. Also, it's kinda "clacky" while in other gears(aka chain is rubbing the derailer). Since the bike is brand new, should I just roll into the LBS? Or is this something I can adjust simply?

Thanks!

Take it back to the lbs. They should have checked this when you collected it unless it developed over time after taking it from the shop. Let them get their hands dirty adjusting it.

yes i agree. You need to adjust the derailer. Also, especially going up to 3, you need to click in into the top gear, but also push it that extra bit furthur for it to change. But it would all be in the adjustment of the derailer cable and position. It is also normail for the chain to rub against the derailer. It depends on what gear you are on your back set. (1-7or8) if it is in 1 to 1, the chain will be on an angle, and will rub on the derailer. If the chain is straight e.g. 2 to 4 (prefered gear), then it should run smoothly, and not rub. I have also experienced this problem, and when to my LBS, that was what they told me. Hope this Helps

Thanks guys.
I readjusted the deraileur tension while riding it. When the crankset was in double and rear was in say 4-6, I just tightened the front until the rubbing went away. I double checked when in tripple front and 1-4 rear. Sounds and shifts better now, but still gonna swing by the LBS for the hell of it.
BTW what causes the cables to loosen? I've been riding it for 3 weeks or so, every day 10 miles at least, and it's brand new. Just breaking in I assume.

They do stretch over time but there comes a point where it seems to 'level off' and it does not stretch as much as it does when newly inserted (my experience anyway). Taking up the slack with the adjuster is the easy solution but there comes a time when it has to be replaced. Better to replace cables often (ish) and keep the indexing nice and precise, rather than run problems with accelerated wear caused by the chain not running so nicely around the cogs.