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27.5x20 vs 28x20 oval fork blades

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27.5x20 vs 28x20 oval fork blades

Old 02-14-24, 11:55 PM
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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.

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Old 02-15-24, 09:01 AM
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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.
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Old 02-15-24, 10:52 AM
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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
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Old 02-15-24, 01:24 PM
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I'm not sure why blades are usually swaged in a little, I always cut that part off.
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