It's not the spool up of the tail rotor it's the lag time of BL motors. This is a hot topic right now in the RC Groups micro helis forum. It seems the 240 is an impatient little gyro. It also might be the tail ESC. Afterall it was only $16 and though it works fine it wasn't made to control a T/R. It also may have to be upgraded. I expected some difficulty with this. It'll take a little time, but I'll think I can get it to work better. Of course Tower is out of stock on some of the parts so that's going to slow things up, and the heli is down right now from the last crash so I'm waiting on other parts. Oi Vey!!