On my 04 1200 sporty 70 mph was the sweet spot. The bike was very smooth at that speed. No vibes or wobble. Bike was stock except for slip on's and a Ness big sucker, plus carb mods. Can't speak to the 883...

 

there's quite a difference in RPM between a 1200 and an 883. I think at some point the 883s got the 29T belt sprocket (from 28), I'm not sure on that.

each tooth on the belt sprocket is about 3 1/2%.
Change the primary from 34T to 38T is about 10%.

I changed my '06 to a 30T belt sprocket and changed the primary, so I dropped the highway RPMs about 17%. ie, from 4000 RPM to about 3350. HUGE difference on the highway. And since mine has been converted to a 1200, I don't have to worry about enough torque for zipping around the city.

The tradeoff of course, it's not as much of a rocket as it used to be with the lower gears.

 

Both my '04 and '12 feel like their screaming at 70 and they're both 1200's.

 

My 99 1200 feels like it can do 70-75 mph all day, very smooth and comfortable.

 

My 2010 Iron starts to scream at 80 and is a little outside my comfort zone. 70mph seems to be comfortable for the most part...

 

What's this wobble some of you speak of? I've had my 48 up to 100mph so far with absolutely no wobble. Now if the wind's blowing hard and just right or I get stuck behind a semi I feel a wobble created by the wind.

 

Your 48 comes with a stock/pre-installed fork brace....

 

Rode the PA Turnpike on Sunday as well, so I know what you're saying about the winds! In a calm day though 65-70 is a nice cruising speed on my 883-1200 conversion Sporty! And there is plenty of throttle left too