Hello everyone.. newbie here with a question regarding my Raleigh Tandem bike. I'm beginning to learn more and more about bicycle terminology so bear with me if I sound amateurish. The other day the front crank assembly came loose. I don't know how these cranks are held down, but I did noticed two bolts underneath the bike so I flipped the bike around to see if tightening these bolts would do the job. That's when I discovered a crack running along the center of the frame directly underneath the crank assembly. My question is this a common type of crack, looks more like a stress crack. The bike is aluminum so can this crack be repaired? I don't see it being a part of the main frame looks more like a weld that supports the bolt retaining area. I will try to post a pic later on because as they say a picture is worth a thousand words. Thanks all. Will