I can't answer your question about jib dimensions, but there are a few factors which would effect leech tension. Mast rake would certainly be one. The angle of the jib sheet (between the clew and the cleats on the tramp) and the age of the sail (if it's blown out) are others. Since the jib block position on the 14T is fixed, you really can't do much about that. But one thing you can do would be to add an adjustable clew plate (if not already installed) onto your jib. Move the jib blocks up on the plate to increase leech tension and down to reduce leech tension.
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