[VonWegener]

If you want to run a 16" harley rim in a stock rigid Triumph you need to move the rim vs. the Triumph hub over to the left. The same would apply to a Harley rim. Now if your rim is a cast wheel you need to widen the left side of the custom built hardtail
accordingly to accommodate that cast wheel.

 

[VonWegener]

yes and btw it isn't important that both wheels are running on the same centerline. Many stock motorcycles don't. The only important thing is that the transmission sprocket and rear sprocket align. The rest you can fudge.