27.5x20 vs 28x20 oval fork blades
 

I haven't handled them personally, are 27.5x20 oval fork blades compatible with cast fork crowns designed for 28x20 legs? Wondering if the difference is more nominal than actual.

Thanks!

There is always some blacksmithing involved in getting fork blades into fork crowns. I might not even notice the difference. If there is a gap anywhere, you can bend the crown into compliance and use brass.

I find the "need" to manipulate the oval shape to fit some crowns. Slight "crushing" in a bench vise can change the amount of large VS small cross section. very few times there's been enough remaining gap (blade in crown socket) where I felt better with using bronze instead of silver fillers. I'll add that the very top few mms of the blade often has a slightly different shape than that a couple cms below the top.

Much of framebuilding entails black smithy type mods, Raking blades, aligning dropouts, Setting lug/socket angles and fits, creating tire/ring clearance indents are all examples of this stuff that are done to some degree with nearly every frame made by hand and one at a time. Andy

I'm not sure why blades are usually swaged in a little, I always cut that part off.