Initially, working twisties was hard, but just required consitently using the "proper" technique. So that's no problem. Then, after riding 28,000+miles on a SE Road King with a 103" motor, I couldn't help but notice the extra weight and heat. Some mods done, the MOCO has already corrected some, and both issues are fixed for me. So 9,000 miles and two years into this experience, I can't think of ANYTHING I hate now. Test ride/rent one like you said and go from there. Trikes are too cool to pass up!!!

trike bike
 

At 62 and having a bad leg and ankle from a 1976 accident I did the unthinkable in the MC world. I converted an '03 Roadking into a three wheeler. Technically it is not a motorcycle. In Nevada you don't need an MC license to operate one and you don't have to wear a helmet if you choose. I actually like my bike more than when it was a two wheeler. Tell yon pops to go for it. They are very stable and love the open road.

Steering
 

Consider putting a rake kit on. Really helps when you are going slow.

I agree that renting a trike would be of great benefit. You're probably going to find that the only rentals will be at the Harley dealerships for the TriGlide. Go to a bike rally and try out the trikes and Spyders. Most will have a demo ride, even many of the dealers will have a demo ride too. Maybe a used Trike off Ebay until he knows what he wants and likes.

Not to side track your thread, but if your dad isn't totally set on a TG suggest that he looks at the Spyder RT model. I love my Ultra Limited and hate the idea of not owning a HD but the people at Bombardier have done their homework with the Spyders. I'd be in a dilema and would have to drive both three wheelers before deciding on either. Good luck regardless and enjoy.

Renting one for a weekend is an excellent idea to help your Dad make his decision. A short demo ride really won't be long enough....

My 2012 triglide is about a month old .....2200 miles....it is way too much fun to ride! My wife is very happy as a passenger too! Everyone's comments here are right on target.

I guess I must live in the wrong area. When I was shopping for my TG in '09, I asked about renting one for a DAY and all I got was a blank look and a stupid smile. "Sorry, we just don't rent out our Tri-Glides". Still don't think they have a rental policy on those trikes to this day. I had to wait for the MoCo to come around with their "dog-and-pony show" to take a free 10 minute test ride.

Trike bike
 

Tell your dad he will love a tri-glide, the wife and I could not be happier, have found nothing to dis-like about it.

I agree - rent one before you buy! If you will miss the leans too much, it's not for you. Other than that- it's the way to go.

I had my 2011 Road King converted, mostly because of my wife's health issues.

You really don't notice a lot of difference when you're going straight ahead, but it's definitely different going thru turns. It's more like riding an ATV than a bike.

I did not get the rake kit originally, but I added a 5 degree rake kit later. It was like going from manual steering to power steering.

If you have issues that make riding a bike a problem, a trike is definitely the next best thing.

http://s7.postimage.org/8o6p5cc5n/Trike.jpg