inner tube pre-filled with pucture fixing gloop;pull the thorn out and the gloop escapes;when it contacts the air, it fills the hole;all you need to do is pump a bit more air in occasionally;a bit of extra weight but a lot less hassle

• Slime Self Healing Inner Tube (Presta, 700x28-35)

Slime Self Healing Inner Tube (Presta, 700x28-35)Slime