21" upfront and air ride in the back, has been this way for months and believe it handles better. I ride solo and 2up and have no issues at all. In the future I will probably lower the front just for looks but the bike currently handles like it did when stock. If anything I gained a solid feel at highway speed!

 

I have a 21 on my bike and have no issues at all, it rides great.doing a 26 on another bike now.it is a lot more involved.i think it wll be drasticly different.a 21 by the time I purchased new chrome legs,calipers,rotors,it was not cheap.may as well go bigger.i think a 23 will go without cutting the neck.

 

Just like most have said the change in ride is so slight you will not notice and will get used to it in a matter of days. I have had mine on my 2012 SG for a year and love it. I kept mine stock and did not lower it. You can't beat the look. Shout out to Coastal Moto who helped me through the process.

 

I've only known 21's- both on my '08 (stolen) Night Train and my current '10 Street Glide. My Glide has a 21' up front and an 18' out back and the thing handles amazingly. Now, I ride an '03 Police Road King for work- it has the stock set-up: normal bars and wheel sizes. Coupled with my Maryland State Police MC training, I can do amazing things on that King that I can't (or won't) do on my SG. I also have 10" mini apes on it so that effects slow speed maneuvering.

Just go for the 21" and don't look back!

 

Have a 21 on my 14 SGS. Love the look and it feels more nimble to me at slow speed maneuvering. Highway speed feels the same to me. Did not lower the front and don't feel it needs it.
Glad I did it and would do it again, if not bigger.

 

Just put a 21/18 set up on a buddies RGC. It handles about the same and looks killer. I am going to put a 21" with WWW on mine as soon as the new Avon becomes more available...

 

I did a 19/18 on my road King. Did single disc so without a rotor it looks killer to me.

 

Man do I loves me some CVO King's...

 

I had a 21 on my last bike an '09 SG for 4 years and 50,000 miles. No issues with handling. I really never noticed much difference. I lowered the front 1" with progresive drop in kit and ricor intiminators to get back to stock geometry. That's probably the only negative. I eventually got tired of the stiff ride so I wouldn't recommend going that route if you lower it. I loved the look. Had an issue finding a tire once while out on the road. I will probably stay with the stock wheel on my roadglide.
Here's a pic.
https://www.hdforums.com/g/picture/647099

 

That is a sick bike for sure. The wheels look great with those Ness lower legs, sliders and that sick paint job! Thanks for your business!