Ishiwata made stuff as light as 015, but I think that guage was practically foil, and very rare to boot. I have a bike built with 022 and have had one with 019 and couldn't tell the diff from the tubing...but the bikes were very different rides. 022 was actually more like the "heavy" stuff, but still not overly heavy and an excellent tubeset in the right hands. I don't know nawthing about Mitchell bikes, is it an Ozzy make?