Small bike red line and max cruising RPM

I sometimes need to ride at 70mph for about 30 minutes on my KZ305. Am I abusing the bike? Tachometer red line is 10K and the tech is at about 7K. Is there a rule of thumb reguarding red line and max cruising RPM?

My Honda CL 350 loved it at 70MPH. The Harley guys were shocked I could keep up with them. 7k doesn't seem to be too hard on your bike if it is in good shape. 

Agree with Steve, if it's in reasonable shape then 7k for 30 mins should be OK (manufacturers have an expectation that small engines will get mercilessly thrashed !!)

Piston speed is the main concern at high RPM, but with small diameter lightweight pistons it is less of a issue. There should be no issue if plugs and oil are fresh, like Wookie mentioned they were engineered for abuse.

Kawasaki's are built like tanks, unlike Honda's!

I once rode my KZ650 for over 30 minutes at 8,500-9000 RPM with no side effects other than a wee bit of oil in the air box (where it is designed to go)