Bibs are 100% FLAT PROOF, airless foam innertubes that replace traditional pneumatic innertubes.  Coming soon! 180/80-14 bib for the rear of the TW200 and the VanVan.  Size 140/80-18 to fit most commonly used aftermarket front tires on the TW200 and VanVan as well as most all 18" rear wheels.  90/90-21 fits most all 21" front wheels.