What do you put back in the tire? A new tube would be ideal, but out on the trail, the truthful answer is, whatever you have available. In order of preference, here is a list: new tube of the correct size, new tube of incorrect size (i.e. 21” front tube stuffed in the rear tire, that is why most riders carry only a spare front tube), or patch the flat tube. But wait, there’s more! If desperate, you can rely on the last resort/Hail Mary methods. We’ve pulled the part of the tube with the pinch in it, secured wire around the tube beneath the hole, and isolated the leak by twisting the wire tightly (it worked.) You can use heavy zip ties to secure a flat tire to the rim if no other solution is found. And we have even stuffed leaves and pine needles into a flat tire as sort of an “organic mousse.” When you’re screwed…Remember you could have been better prepared.