What's the top cruising speed for a evo,mine is almost screaming at 85

 

Relative to model and pulley ratio. Most of the Dynas I've had were best @ 70-75, my Heritage is great at 75 -77, my RoadKings 75-79.
A dyno TECH best described proper cruising speed to me as high gear and watch you mirrors until they quit shaking or shake the least. Think about it engine running smoothest and effortless. 85 - i can run it, no problem, but is definitely not cruisin speed.
If you're wanting to roll smoother at a higher speed, dropp a couple of teeth on the rear pulley.
What model are you running and what pulley sizes.

 

Seems like the RK's are comfortable at 75 all day like TSheff mentioned, once got on the stupid train and was pulling away from buddies racing in South Dakota, they were running 114, now that is cruising on a RK, never have done it again.

 

I have my ride set up for 2600 @ 70 mph, very comfortable and easy to mange however at times it does like 135+. exhilarating.....

 

My 1996 Ultra Classic does 85 around 3500 rpms, seems to handle that pretty good.

 

I run my 95 flt 70-75 a little over 3000 rpm all day 2up . there is a nice smooth
spot there and there is still some throttle left to pass.

 

3500 RPM on the slab sounds like you're working it too hard. You're not. They like it.

 

Running at about 3700 at 85 and it doesn't bitch. I've run it at 90 for extended periods of time (over 100 miles) without issue except for loose parts and crap.

 

Just doesn't feel like it liking 90 at all.

D

 

The bike is fine, it's you and your ears that are 'screamin'! If you want to cruise at those speeds just wear ear plugs. We were first alerted to the noise levels we are subjected to back in the mid-'70s, but the message is still not getting through. I wear them on all but the shortest trips and have done for 40 years - best tuning aid known to mankind! Your bike will be a darned sight quicker.