Check out "Texas Advanced Motorcycle Training Video (TXAMCT.com)" by the guy that developed motorcycle drop guards. He has the most control of any body I have seen.

 

18’ is a comfort zone u-turn. I practice every spring. My three operating rules.

1. Turn your head and look where you want to go.
Never look at the curb, road edge or obstacle.
2. Up revs slightly and ride the friction zone on your clutch.
Easy minute control. Steady throttle, friction zone gives control
3. Rear brake only to control speed. Balanced against the up revs and friction zone.
No front brake. Front brakes are for straight line braking or trail braking. No need in a slow speed turn unless you want to go down.

I’ve also practiced my emergency stopping from 40+. Straight front wheel, bike upright, front 90%, brake only lightly as a rear lockup is bad.
I also practice my swerves at 40+

These are my get out of jail free cards.

 

I practice low speed maneuvers on my mini-bike. It's less wear and tear on the Harleys and the skills carry over to the bigger bikes. If I make a mistake on the mini-bike it's less expensive and maybe get a couple of bruises at the worst case.

 

The swing is the way I do it as well. I have found its a mental thing to turn those bars even further as someone posted to lock position. I still have a hard time with that, but I know the bike will do it, and I can do it, just need to push those bars a bit more to decrease the radius.

OP you skills are probably above 90% of the riders I see on Harleys.

 

I've always wanted to get better at the low speed maneuvers since I started riding in 2015. I decided this is the year to get serious. I've been watching Jerry Paladino for a while, and this year I found Robert Simmons' channel.

One challenge is finding a place to practice. The nearby school lot is gated. I've been going to a DOT lot, which is about 10mi away, but only after they close at 5pm.

I've been alternating practice on my Dyna Low Rider and Street Glide. The best I can do right now are 19' turns. There's about another 1/2" to push before the bars lock, either fear or a mental block is preventing me from getting there. I feel like I need to lean a little more to push the bars all the way, but I haven't found the stones to commit. I also tend to slow too much when I'm in the turn, instead of going through it steady like pyuchem posted.

 

Don't push yourself beyond what you are comfortable with. That can lead to trouble. Keep practicing within your comfort zone until your skill levels and familiarity come up to where you can safely push it a little harder. A 19' turn is just fine. Not worth dropping a bike over.

 

Place:
That is the beauty behind finding a marked parking area. As you saw above, you can scoot into any marked parking area and practice at a moments notice. Putting down cones and practicing is a different story.

For the cones, if you have a university in the area or some large facility that draws a lot of vehicles like a stadium or a flea market, etc. you can try to use their parking lot maybe on a Sunday morning or other odd time when it is apt not to be used.

Even some churches have large parking lots. It is not like you marking up the ground with chocolate paint.

Another thing you could do is maybe find a location where the police practice. That is what I did. The bonus is the ground could already be marked up. It likely that is. Also if you're practicing most people will leave you alone because they used to sing the police out there. Like if there was security in the area. They are more apt to leave you alone.

Either fear or a mental block:
I kind of agree with PeterB. Know your limits and stay within them. But honestly I am also fighting with myself to push your limits. But first I would like to emphasize before going any further that if you doing 19 foot circles, then you doing incredibly well! I am assuming 19 feet each way. Left and right. Most the time people are good with one side and not so good with the other.

I think when you practice it enough, your confidence will go up (don't get cocky as I said above in a prior post) but maybe you want to make an effort to really look behind you and lock those handlebars. I am emphasizing at this point looking behind you because when you use your mind and think about locking the handlebars, too many times people lose looking behind them like an owl looks behind themselves. They will not lose so much the RPMs, feathering the break, or friction zone. They tend to lose where they are looking and start to look down which is a big no-no.

I don't think I would push it if you're at 19 feet. That is very commendable. It really is. Maybe it is your own personal satisfaction to push and get that extra 1 foot under your belt.

If you have to do a tight turn, most single roads I think are around 20 feet or 22 feet or something like that. So a 19 foot diameter is pretty good.

And lastly on the matter, you said it was a "… either fear or a mental block…". What you may want to do is program yourself, think positively, picture yourself locked and low, looking behind you using the technique and nailing it beautifully.

Keep in mind the famous story about the guy that was in "Hanoi Hilton" in Vietnam. The story goes something like this. Every day in "Hanoi Hilton" (prison) he pictured himself playing golf. He never played golf in his life but he pictured himself playing golf. When he finally came stateside and played golf he was an excellent golfer. It is more a mind thing, confidence than anything else.

Clearly you already have the technique. Again, and I cannot say it too many times, kudos to you!

You have been riding for about eight years, and you are beyond a bazillion others who have been riding a lifetime. Awesome job!

 

I bet you turn your Street Glide better than you do your Dyna. Do you? I ask because the Street Glide has a 26 degree rake. The Dyna has something like a 30 degree rake( last I checked). The Glide should turn tighter. Maybe Buzz can verify that.
Buzz has told you what and HOW you need to practice. Personally I'm betting you will get to under 19 ft turns in the near future. I say that because the more comfortable and better you get at the 19 ft turns(which is amazing in itself) you will just naturally turn those bars to full lock one day in practice, and voila!, you've got it! By the way, this is not MY wisdom(lol), it comes from motor cops. EVERY SINGLE ONE of them has told me that it was about Thursday afternoon in their training school when "the light came on", and they "got it" on how to LOOK , LEAN, and Full Lock Turn.

Man, you are so close it's scary. LOL! But then again, I have to say, YOU"RE DY-NO-MITE now!! Patience Daniel...patience.(from Mr. Miyagi )

 

Swing, depends. If we stop as a group and decide to go back for …..lunch, another road, what ever reason, I’ll just initiate the u turn from a stop.

If I’m moving and decide to go back, I do swing a little before just whipping around. I not sure it was taught, but it feels natural and comfortable. Not much, I wonder it if is really noticeable to a non rider. But it does seem to help if you are making a rapid u turn.

 

This whole thread put me on the wayback machine. Picture 1973 and me and my friend Paul are chillin on our small jap twins in his front yard, when up pulls his big brother on a chopped BSA with a springer front end that must have been 6 feet long! 18' u-turn heck he couldn't do a 18 yard u-turn; but he looked cool LOL.