I went from a 1200 Sportster Low to a Electra Glide. If you feel comfortable on your Sportster, you may want to take the Harley Advanced Rider (Rider's Edge) class with a UC, RK, or whatever. Around here, its one day and costs about $100. They will rent you a bike if you don't bring your own.

There are tons of videos on YouTube of motorcycle rodeos. The police ones are my favorite because they appear to have the best handle of their bikes and they typically ride domestic bikes. This one is my favorite. With practice, you can really swing these bikes around and they handle very well.
Police Rodeo

This is a rodeo that has RKs, EGs, BMWs and Hondas all head-to-head. It was at my local Timp Harley in Lindon, UT.

The two biggest factors for me are throttle control, (giving the bike enough throttle to maintain speed in a turn), and spotting, (looking where you're going). I can lock the handlebars doing figure 8s with only the trottle (no brakes or clutch). Its much easier that way. They go over all of that in the Harley class. At the end, you'll probably be scraping the floor boards like the guy in the video.

As far as bikes go, I'd recommend getting a cop bike (Road King or Electra Glide). You'll need to buy a lower seat as the cop seat is fairly high. I like them though because they have crash bars on them from the factory. I've dumped my bike trying to park a couple of times and the crash bars keep me from mashing the saddle bags and handle bars/levers.

They are also cheaper. I found a few around here with 3-12k miles on them for around $11k a few days ago. They are usually older, (2004-2006), but they're usually very well maintained.

I have a 30" inseam and am 5'9".

 

I fully understand your apprehension. I have owned my Roadking for about 18 months now. The guy i bought it from delivered the bike to my door and put it on my drive. I can remember my nerves as he left and thinking to myself, how the hell am i going to be able to ride this beast. I looked at it out of the window for a couple of hours before i plucked up the courage to even get on it, let alone stand it up. The first ride was a mixture of pure fear and also the realization of a 40 year dream to own a Harley tourer....... Now 18 months on i find the only way to get the grin off my face is to suck on a lemon!!!

 

I went from my low center of gravity SuperGlide to a RoadKing .
Stock RK set up way to high, I couldn't flat foot it .

First off i sent my Stock seat to MeanCity Cycle , they narrowed and lowered it and added some memory foam to keep it comfey. This MOD was just under $150 including shipping both ways .THRIFTY !
Way more thrifty than a new seat .
Next i installed the HD jiffystand exstention only $30.
that might do it for you.

I wanted to get it a bit lower i am short ,so i got some 11" Bitchin Bagger shocks .
They are stock HD air shocks that have been cut down , new springs and oil .
I also raised my floarboards up one notch.

I also practice slow speed riding in a parking lot .

Stay off the front brake at slow Speeds.

Consider taking a riders edge course .

Check out some of the riders edge clips on youtube.

 

I should have clarified that we were talking about 900 lb. Harley touring bikes. And yes, there are methods like you describe to "make it work". But a properly fitted HD touring bike will be easier to handle.

 

Yes with the Big bike you have to think before you park. Some places I just pull in with my sporty Id really have to work to get out with the glide.

 

My RKC is the only bike I've ever had. I gave her a lot of respect and handled her very lightly the first month or so and now there really isn't anything I can't do in a parking lot on her. It just takes time and practice.

 

I went from a XL120C to my eglide, while riding it home the 60 miles, first thing I notice - I was WAY too tense. It was like I was waiting for the dreaded unseen bump in the road that would bounce you 6 inches up off the seat on a sporty, I relaxed and the next thing that scared me was OMG! those things on the handle bars, if you look at them you can see what's behind you. Unlike the sporty were they are for instant dizzy spells. It will take a few miles but you'll get use to it. I did find out that I can't bounce the bike back and forth between my legs while standing up at a stop light like I did with the sporty. The extra weight tends to stay in motion. LOL.

 

I went from a Honda shadow 750 to an ECG ,and I had never ridden one before,just got on it rode You will get used to it just pay attention! Im 5'10" 160lbs. Scrawny peckerwood!

 

I had a road king and an ultra at the same time. The king did handle a bunch better in parking lots and the ultra seemed like a truck for a while. Now I have a wide glide and the limited. If I ride nothing but the wide glide for a week or so, when i get back on the ultra it seems huge again but in no time at all the size goes away for me. I ride mostly highway and country miles. If I rode mostly in town and only had one bike, I'd have a king, not the ultra because it'll do both 1 and 2 up and it handles better in town but on the highway there is nothing like an Ultra.

 

I went from a Yamaha 750 Maxim to a Road King Classic. The first couple of weeks, I didn't want to get on the Interstate preferring to stay on the side streets. I didn't feel confident when making corners and had a few turns that went wider than I wanted them to. I bought the "Ride like a Pro" videos and started practicing in an empty parking lot. I feel much more in control of the bike and a lot less nervous about it all. I am finally making tight turns, full lock to lock, and enjoying riding much more then ever. The RKC doesn't even feel that big to me now. I've had it for a year and 9 months. I am 6'3" and needed to put a Tall Boy seat on it. That's the only fitment mod I've done.