It's a combination of things, wall thickness, butting profile, tube shape. The Niobium alloy they use is the same across Spirit and Life tubing.
Not at all unusual to mix and match across both ranges to get the frame design you want.
@Mikenetic started
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It's a combination of things, wall thickness, butting profile, tube shape. The Niobium alloy they use is the same across Spirit and Life tubing.
Not at all unusual to mix and match across both ranges to get the frame design you want.