can you re-use your front tire when changing from the stock spoke wheel to a new custom non spoke wheel?

 

Yes

 

All things being equal between the old and new wheel, diameter, width etc, you can reuse the tire.
H-D just uses a tube inside a tubeless tire when its installed on a laced wheel.
Look for the word "tubeless" on the sidewall of the tire.

 

If it is the stock tire and the size is the same, it can be used.