'77 GL1000 swingarm driveshaft tunnel. It appears that someone took a grinder to the seam to make room for a wider tire. Trouble is, they left an opening about 3/16 wide and 3 inches long. There is some rust on the driveshaft u-joint, which is died out and "notchy", I soaked that in oil overnight and it freed up 'pretty good'. I will weld a patch over the opening and paint it, current tires fit just fine. I can't think of any other way for that opening to occur...I hope they thought it was worth it!