I have a shark pack battery that I currently have mounted on a rear rack because I have no water bottle bosses on my down tube. I would really like to mount the battery on the down tube however. Short of drilling holes in the down tube, the frame is aluminum, do any of you have a good solid way to mount the battery? Actually, even if I did have bosses, the battery mount is flat whereas the tube of course is curved. I don't see how this would be very secure anyway, am I right?
