Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

If anyone tests the hollow belts, I would love to get feedback on how they work out?
  My primary interest was a softer belt that conforms to the shape of a small Diameter pulley at low belt tension, but I am also curious how well they transfer power, for instance I was thinking what if you had a Solid 2mm belt And the hollow 2mm, which would slip less under load? If the pulley groove is say 2.5mm will the hollow belt squish oval under tension and give a greater contact patch?  Or any other observations (good or bad) would be great, thank you!