thx for the reply Doug. As I mentioned at my track I am often the only shifter so there isn’t anyone to follow. When the state race comes to town (Florida Karting Championship Series) I run the shifter masters (I’m an old fart) and finish on the podium the last three years in a mixed class of ICC and Mod Moto (I’m running Mod Moto). Typical class is at least 10 karts. Not trying to claim I’m any good just trying to provide a reference. My braking habit comes from the formula ford days and I was a trailbraker. So in the shifter I do trail brake which is different than you suggest. I do run an enduro event with a 4 stroke single speed kart where I do intentionally use trail braking to slightly lock the rear at corner entry to help rotate the kart but in the shifter the bias is set to lock the front just slightly before the rear so trail braking doesn’t help rotate the kart. The speed and power of the enduro is so much less than the shifter I don’t think it helps me address the racing line question. my original motivation for the question is to improve…if I’m using slow lines I want to fix it and go faster!!!