A great suggestion, but I would like to add a bit to it.
If you do this and want the V groove to go all the way to the end of your work, clamp a piece of scrap with the same edge profile on both ends of your work. This will give the bearings something to ride against for the short distance needed to cut the beginning and end of the V groove correctly. If you don't do this the V groove may be cut wrong as the bearings enter and leave the ends of the work because only one bearing will be in contact with the work.
There are bearing accessories available for many routers on the market that allow you to do this, but they only have one bearing, requiring you to maintain very accurate orientation of the router to the edge of the work as you make the cut. It gives you the ability to get the correct spacing, but fails in maintaining correct router orientation to the work edge.
The 2 bearing method that Keith posted is far superior for doing this. You just need to have a way to guide the bearings at the beginning and end of the cut.
Central North Carolina