Do you mean Bonnie to triumph America or American bike?? If former that's your personal choice and if you want to you must have a reason to want to, if it's the latter...............
The triumph America bit different like the look of laid back style want to go a bit further afield travel wise
Very much your personal choice - can you arrange a test ride? Personally will always prefer the Bonnie/Thruxton/Scrambler classic look to that of a cruiser.
Had a thunderbird Lt as a loaner and was very impressed, straight off a Thruxton! I found it dead easy to ride and very comfy, if I was a cruiser sort of go with it
The Thunderbird is the 1700cc though isn't it? And a lot more dough as well I think. I rode one too and it was very impressive.
i would say go for it, i think the America is a cracking looking bike,it will feel differant to your Bonnie and will probably take you a few miles to get into the swing of things,the pull back bars will make the front feel light (compared to the Bonnie) and i imagine it will have a bit less ground clearance, probably more so if it has the foot boards so you will have to line up the corners a bit earlier, i have a cruiser and it has the foot boards and i love it
Book a test ride, only you can tell if you are going to enjoy the ride. Personally love mine, have rode all types and have different feelings for them all. Good luck on your choice, certainly more laid back for distance.