What was a noted weakness of the thread produced by James Hargreaves' Spinning Jenny?

Answer

It was often loosely twisted, better suited for weft rather than warp.

While the Spinning Jenny drastically improved output, the resulting thread was often loosely twisted, making it better suited for weft (the cross-thread) instead of the stronger warp threads.

What was a noted weakness of the thread produced by James Hargreaves' Spinning Jenny?
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