Hi, I just bought a new 24speed road bike and notice it makes a grinding sound when I pedal. Seems like no matter what gear i'm in the chain goes "clank clank clank". it's worst in other gears and it gets really loud and the pedaling isn't smooth. I have looked over the chain and its not loose or anything.

sorry i'm new to road bikes/bikes with gears, i've been riding a single gear BMX bike for years now.

If anyone know what that problem is I would really appreciate the help.

Thanks.