not sure which bike u talking about. but. changing the front tire size in height could result in a huge difference in handling . taking corners . amt of air coming into cool eng. ect.. it's like back in the chopper days extending the forks changed way you could turn an amount of space u needed to turn.
I have the same bike you have. I had a 21” on my Victory Magnum prior to this bike. And it will change the handling I can guarantee that. It’s gonna take a bit more muscle at slow speed maneuvers. And there’s a good chance you won’t be able to fork lock it and spin it around in a short circle anymore. But they look kool.
21 is as big as you should go with a 120-70-21 tire
the bike will handle slightly slower and you will need fender spacers
forks are fine,neck is fine, if youre wanting something bigger it turns into a showbike that is ridden once in awhile
Went through this a couple years ago. The stock fender will need risers. Customs ones for a 21" that require no riser are available. Anything bigger than a 21", which requires a fender rise of 1.5" for the current fender or 1" for the valanced fender, will cause the fender to hit the bottom of the triple tree when the stock forks are fully compressed. Also, there are more manufactures and availability for 21" than 23" tires in the proper size and load rating, something to think about if you have a flat and need a replacement quickly. Agree with the others that low speed maneuvers are a little more challenging, but higher speed seems easier to flick the bike back and forth in turns. Oh, and your bike will lean over a bit more on the kickstand since the front axle will be about 1.5" higher.