I have a 2007 XL883C with 21 inch spoked front wheel and I want to change to a 19inch spoke or mag ( don't like the 21 too skinny) is it a straight swop or are there things I should be aware of?

 

So long as the 19" wheel is designed for a 2007 then it will fit without a problem.

It is all over the forum which year has which bearing sizes.

Example of 19" wheel from a 2007 883 - https://partsfinder.onlinemicrofiche...FRONT%20(CAST)

I did the same thing on a 2008 Custom. Just got a wheel from same year and had no problems.