Freedom Thorn Resistant Tube 27.5 x 1.9-2.4 48mm Presta Valve with removable core Designed to be thicker on the road side and a little thinner on the rim side to keep the rolling weight lower than a standard thorn resistant tube. Our friendly team can help you find the right tube for your bicycle or other requirements. Check the size on your tyre to help select the correct size tube. Check your valve type and length.