Failing to unscrew BB - what now? I have an external bearing BB, that I need replaced (It is quite badly rusted). I opt to do the repair myself. The bike is a Specialized Hardrock, the crank arms are SR Suntour.

Having removed the crank arms, I proceed to unscrew the plastic sealing rings of the BB. I removed the non drive side one. However, with all my strength, and a 30cm arm wrench I fail to produce any progress on the drive side cup. I am trying to turn the cup clockwise.

What is going on here? Am I doing something wrong? If I go to my LBS, is it probable that they will have a larger wrench?
I tried both techniques proposed here, but to no avail (I might have damaged the BB with the hammering).

The LBS had the tool for the job - experience. The guys put the wrench in a vice, calculated the direction to unscrew carefully, then put the frame on and just unscrewed the damn thing. The frame was providing large leverage.