I just went through trying to find an inexpensive front that fits. I found most of the cheap ones were anywhere from .004 to .010 too thick. I ordered a 12T Renthal and it fit fine, exact size it was supposed to be. Here's the big trick for getting it to fit: Use a new circlip. Also make sure mating surfaces are spotless clean and free of burrs. We're talking about a couple of thou of an inch here so it makes a big difference. Use proper circlip pliers and it will make removal and installation much easier, when you use improper tools to remove them, they get bent and won't sit in the groove properly.
Once you get the clip on the shaft, you may need to tap it all the way around to get it to seat in the groove.
Hope that helps,
Glenn