I'm a pack rat. Whenever I go out for a ride, I often feel the need to carry extra gear. Lots of it. So naturally, I decided I needed a big huge motorcycle purse.
I ended up deciding on the enormous Tecknic Modular Tank bag. The Tecknic Modular Tank bag is a 3 part system: a base with magnets(or straps) to hold it to your bike, a nylon reinforced large bag for gear, and and another slightly smaller soft bag. List is around $130 and I got it for a song at $40.
When I got it, the bag did not disappoint. The quality was good, and the three parts of the system were easy to assemble and disassemble. The bags themselves could hold SO much crap. Nirvana.
But here's the kicker and the reason for the title: the bag itself was too much bag. While riding with all three parts, the bag would interfere with the operation of the motorcycle( in this case, an old airhead-a BMW R80 RT ). In several instances, the bag itself would flick the kill switch on my bike. Not good.
So, dear reader: be warned. While it's a nice bag, either plan on only using a subset of this bag's bits or verify that this bag fully deployed doesn't pose a safety risk to you on your motorcycle.