The reason I'm asking is because my wife's track bike keep losing chain tension after she's been riding for 2-3 hours. This only happens after I do some kind of work on it, so I know it's my fault. Today her chain got so loose it looked like it was going to start rubbing on the chainstay. When we started the chain tension was as tight as possible while still able to spin freely.
The nuts were as tight as I felt comfortable tightening them. In order for me to make it tight enough to not ever slip, I really have to crank that thing down. I worry that I will damage those thin drop outs!