It’s always worth carrying a spare tube when you go out for a ride, because it’s much easier to pop a spare tube in than to fix a puncture by the side of the trail or road. But it’s definitely worth backing the spare up with a patch kit. Punctures often come in batches and carrying more than one spare tube gets bulky. So, hold onto your punctured tube and fix the puncture at your next opportunity. The repaired tube can become your new spare.
To repair a punctured tube, start by locating the hole. Pump up the tube to about twice the original diameter. You might be able to hear the air hissing out of the hole straight away, and locate the puncture that way. If not, lick the palm of your hand and move it along the tube, about a centimetre away; you’ll feel the cold air from the puncture on your hand. Roughen the area with the sandpaper from the patch kit; this helps the patch stick – and means you don’t lose the hole. Let all the air out of the tube again. Spread glue in a spiral out from the centre of the hole, making a glue patch that’s generously bigger than the patch. This next step is the most important – let the glue dry completely. In average temperatures, this means five whole minutes. In the desert, you can wait two. If it’s snowing, blow on the glue patch to keep it warm. Once the glue is dry, peel the foil off the back of the patch. Don’t touch the rubber surface of the patch at all – use the clear plastic or paper to hold the patch. Drop it into place, then don’t move it. Press it onto the tube with your hands. If it’s very cold, clamp the patched part of the tube under your armpit to keep it warm enough for the glue to work, about another five minutes. You could peel the plastic or paper cover off next, but normally leave it in place – it weighs nothing and saves you accidentally tearing off your neat patch. Refit the tube into the tyre before putting pressure into it because the newly stuck patch is vulnerable and won’t stick properly until it’s trapped between tube and tyre under pressure. Puncture glue doesn’t last long once the seal on the tube has been broken – it dries out in six months, however tightly you screw on the cap, so replace it regularly.
Schraeder Inner Tube / Valve
There are two types of bicycle valve: Presta and Schraeder. Presta is the thin one that road bikes always have. Schraeder is the fat cartype
valve. Cheaper mountain bikes sometimes come fitted with car valves because they can be pumped up at petrol stations. Presta valves are designed to work better at higher pressures and are more reliable – Schraeders leak if grit gets caught in them as you pump them up. We always use Presta, but there is a bizarre law that says if you meet a stranger on the trail who’s stuck because he can’t fix his own puncture, he will always have Schraeder valves, so you can’t help him with your Presta pump. Luckily, most pumps now convert to fit either type of valve; with newer ones, you simply push any valve into the pump head and flick a switch. Many older ones require you to take the cover off the pump head and remove a small rubber grommet and a small plastic thing. Turn both parts over and refit them into the pump in the same order they came out – plastic first, then rubber. Refit the cap, tighten it hand-tight and you’re ready.
Presta Inner Tube / Valve
Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES