I'm not sure why people say 5th is useless. ???

I know once I hit 50-60 I shift to 5th and I can feel the power difference not to mention she sounds better at 65 in 5th than 4th.

Say I never used 5th gear...how does that affect cam chain stretching over time?
say I cruised 70- 80 in 4th?
Any extra damage or wear to worry about?

There is a very good reason why its not 600 rpm less,.....
these engines...stock simply do not have enough horsepower to run that slow at freeway speeds. Even 5th gear is too high at 70 mph now,......the engine is working hard ! I happen to have a vacuum mounted, and see very little vacuum,.....almost nothing at 70 mph,.....not a good thing. And if you were to use a higher 5th gear at 45-50, its ok, untill you want to accelerate much at all, then you are chugging it to death,......you know,.....like tryin to hammer the crankshaft right out of it. So that means shifting to 4th all the time, so then why have a higher 5th gear

I have NEVER seen a problem from spinning an engine fast, but I have had disasterous results from working an engine too hard, like sticking a piston at 70 mph, all from working the engine too hard.
I think Suzuki has it right.
bill67 wrote on 08/02/10 at 15:59:03:

Turning a little over 5,000rpm at 75mph. Not sure if I would call it chugging. That is more than 3/4 of the rpm range, just almost 1,500rpm shy of redline. At a little over 5,500rpm it starts to lose HP, with going down drastically

My 5th gear is a bit cranky, but I only use it over 50 or so which isn't often. We usually cruise at 45-50 on country roads in 4th at 3800. I have a cheap $35.00 tach that I bought for this very reason. I try to keep it below 4000. That's when I go into 5th.