At what speed should a ride a new Yamaha R15 ?

I have heard that i should not go beyond 40 km/h with a new bike for around 1,000 Kms, is that true ? Is the case same for Yamaha R15 too ? Please let me know. I have drive my bike for 200 Kms with average speed of 40 - 45 Km/h. Sometime i also take it around 60 km/h in the 6 gear. Let me know your thoughts.