welcome to the 40+ crowd!
as far as the fastest on level ground, i hit 54 with a heavily modified china, gps'd and witnessed by neil (motorbikeracing) and the aleman.
hit 62 on the same bike drafting a truck, gps'd with my phone, and then blew the motor apart.
there's lots of guys hitting 40 on china dolls. just takes the right mods and some balls.