You do realize you can't just say, "You get them on my weekends bc I have to work", right? I mean you have to ask and she has to agree. She may have other plans those weekends. Then if it is your weekend you will have to find someone to watch the girls while you are at your race, and you will have to pay them (unless you have family nearby to help).
I say this bc my ex travels 10 work days a month. Many fall on 'my' time so it doesn't matter. Some don't. I keep them 80% of the time when he is out of town but sometimes I am busy. So his parents keep them. Or he sends them to day care.
Basically what I am saying is ideally she agrees to switch with you but if she doesn't it is on you to figure out what do do on those weekends. Part of the crappy reality of divorce...
