Hi, I've done a few searches to no avail. I'm hoping to gain some insight from the responses. Anyways today I was driving on the interstate (~65mph) on my 06 KLR650. I started getting a weird vibe about how my bike was handling. Something felt a little loose. So I gave a mild blip of steering input to initiate a mild countersteer, just to kind of test and see what was going on. What resulted was a mild tank slapper which was gentle and very easy to control. I gradually slowed down and pulled onto the first exit ramp and stopped rubber side down (this entire process probably happened within a quarter mile -- the description may make it seem longer, but my decision making was very rapid). When I was driving it felt like my front forks were kind of twisting around. Other people on the internet are describing it like they were sliding on ice -- however they are also describing much greater loss of control Anyways, it turns out my rear tire was flat. But I am curious -- why would a flat rear tire cause a tank slapper? What is the theory behind that? I'm really glad I didn't get hurt -- reading some horror stories online now. Worth noting: I had 40 lbs of gear on the cargo rack, but I'm light so me and my gear weigh ~200lbs. Also, this was my first rear flat tire while driving (had others leak overnight and I've had front tires go on me) and my first flat tire at interstate speed. Any ideas on the theory behind this? Again Google searching didn't help. This is a fairly common problem...someone should know, right? PS: while I was on the side of the highway I had three bikers offer me help. It is really cool to be a part of this brotherhood, so to speak.