Makes sense that the rear aren't doing as much and would lock up first, never thought about that. But I also have noticed that if on my daily driven 59 Rambler my ebrake is on just a little bit where I didn't release it all the way, the rear brakes lock up very fast when applying the brakes just above normal hard a bit. So adjustment has a lot to do with it too. Where as under normal hard braking, they don't. I even had a serious panic stop a while ago and they didn't lock up, it was beautiful.