Timbone,
I love the way the 21" wheel looks. I really can't tell any difference in the ride.
Dean.
I had a 21" front wheel on my '07 FLTR. At most times, I could not tell any difference. However, I noticed that the front end would sometimes get squirrelly when going through corners at speed on the freeway. It would develop a bit of a wobble from time to time. Last summer, I picked up an 8" KW windshield for it and that helped a lot. From what I understand that windshield creates about 40lbs of down pressure on the front end which really stabilized it in those high-speed turns.
One other thing, the 21" wheel and tire was about 1.75" taller than a 16" or 18" wheel and tire. I never lowered the front end. So, it sat up a bit and made the bike a bit top heavy, particularly at stops and low speeds.
As far as the looks of the 21" wheel and tire, I loved it! Very dramatic on the front of a bagger.
I've noticed that some of aftermarket companies have started making 23" front wheels for bikes. The owner of my dealership custom builds a new Road Glide every year. His '08 had a 23" front wheel. It was stunning. Not sure I'd want to take that on though. It seems to me that the high-speed issues I had with the 21" might be worse with a 23". Can't speak from experience, though.