I'm glad it worked for you. I did the same thing on my Fuji, except it was Suntour 14-24 6-speed to Suntour 13-28 7-speed. I ended up swapping a few cogs on the new freewheel to increase the range to 13-32. I had to add a small spacer to the axle to keep the outermost sprocket from rubbing the chainstay. I had to switch to 7-speed chain, of course. And it took a little trial and error to get the chain length right so that the existing derailleurs could handle the range. But other than that, it was pretty easy. Now I need to replace the decal that says "18 SPEED" on the chainstay, since my bike is now a 21 speed.