Having done it now, I'd say it's an easy conversion. The Vulcan kit should come with all the right hardware, spacers and parts. Drop the wheel, pull the forks, remove the old triple clamps, install the new clamps and reinstall the forks. You have to get the spacers right for whatever wheel you're going to use...I got the 16" wheel in a 39mm wide glide kit, also from vulcan. You also have to consider what you're going to do for the headlight. The Nightster headlight mounts to the top triple clamp and the Vulcan kit has a lower clamp mounting point, so we had to fab a new mount and flip the Nightster headlight over to a bottom mount configuration. Like I said, if they send you all the right parts it's a pretty easy conversion. If not...

 

Does anyone know if you can fit a wider rim with this setup? Maybe a 16x3.5 instead of the 16x3?

 

Look at mine and draw your own conclusions...plenty of space here. These are '06 RoadKing wheels with 150/80 tires mounted.