Bicycle Flat Tire Changing Clinic At some point, you will have a flat tire. Learning to change a flat tire will help you feel more confident while out on the road and the skill may allow you avoid making a call for taxi service. Tool & Supply List Spare tube –in a plastic bag with a small amount of baby powder 2 Tire levers Small hand pump Dollar bill Hand wipes Air cartridges and applicator (optional) Patch kit (optional) Bag to carry it in Spare Tube – Be sure to carry a tube that is specifically sized to your bike’s wheels and has the appropriate valve type; almost all road bikes use the Presta type valve, not the Schraeder. Also note valves come short or long; the shape of your wheel will determine which length you need. If you’re not sure, ask your bike shop mechanic. Give this vital item some extra protection by storing it in sturdy zip lock bag (the heavier type) and make it easier to install by squirting a small amount of baby powder into the bag before putting the tube in. The powder-y tube will mount into the tire far easier than one just out of the factory box it came in. Tire Levers – You’ll need only two, even though they come in sets of three. Look for nylon, sturdy models and leave the metal type at home in your shop, no need for the weight. Small Pump – We usually mount these to our frames, but some prefer to carry in a pack. Our favorite right now is the Lezyne which is light, and most importantly, can produce the high pressures we need. Most road bikes will do best with a pressure of 100 to 120 psi (more on this in a moment). When you select a pump, be sure to verify that it will go that high – not all do (mountain bikes, for instance, never run with pressures this high). Also be sure the pump fits your type of tube valve – Presta or Schrader. © 2013 Velo Girl Rides, LLC. All Rights Reserved. Page 1 of 12 Dollar Bill – or a 4” x 6” scrap of tyvek, or similar very thin but super tough, flexible material (dollar bills are manufactured to put up with rough handling and survive). We’ll explain how to use this later. Handwipes – Although back in the day, wet grass was the best alternative to cleaning up the grease and grime from changing a tube, we now have access to cheap, individually packaged handwipes… buy a box, and keep 2-3 of these little envelopes in your tube-changing kit. Air Cartridges -- We have found the air cartridges can easily malfunction, and don’t fully inflate the tire… and small hand pumps are now available at nearly the same weight. And optimal flat repair calls for the ability to partially inflate the tube to check for leaks, before installing a new tube, and that’s hard (if not impossible) to do with a cartridge. But this is a matter of personal preference, and because you could be pumping that small hand pump for as long as 10 minutes to get the tire to full inflation (it is a very small chamber in the pump) some riders choose to carry both a pump and the cartridges. If you do decide to carry air cartridges, don’t wait for a “tire emergency” to learn how to use them. Plan to “waste” several, learning how to use them at home, to minimize malfunctions on the road. Patch Kit -- We haven’t “repaired” a patch on a tube on the side of the road in years – a tricky business under the best of conditions. So we don’t carry a patch kit on the bike, but we do bring one on multi-day rides, along with extra spare tubes usually carried in a vehicle. We may repair tubes at night, to increase the number of spare tubes. Bag – Most road and mountain bikers will carry their tire repair tools and supplies in a “wedge” style bag under their seat. The rationale is simple: it’s always there, ready when you need it. If you use this bag only for your tire repair gear, and a micro tool (a micro tool is vital to making other adjustments on the bike, but isn’t used in changing a tube), it can be quite small. Some riders however prefer a larger bag, so that food, car keys and other items can be stored conveniently. But beware – storing other items in the bag can puncture the tube. And getting in and out of the bag all the time might cause you to drop a lever or the dollar bill, leaving you underprepared for a quick tube change. So you might consider using your wedge bag exclusively for repair items. Just sayin’. © 2013 Velo Girl Rides, LLC. All Rights Reserved. Page 2 of 12 Get Off the Road Stop riding as quickly as possible when you realize that you have a flat tire. Find a safe place to work on your bike and get out of the road…completely. As you fix the flat, you will become preoccupied with the task at hand... and remember that it will not be possible to “jump out of the way” fast enough if a vehicle sideswipes your position. About 350 workers (on foot) are hit and killed every year in the U.S. by vehicles mowing them down on highways and roads (CDC & NIOSH). And they were wearing mandatory high-viz vests and had the benefit of warning signs, cones, and flashing lights on their vehicles. Nevertheless, they were hit. You are even more vulnerable given that you may not have a Lime Green vest, don’t have a big dump truck to protect you and don’t have high-powered flashing lights. You too can become a fatality if you’re on the edge of the road. Please move completely off the road, not like the people in this picture… they’re on the wrong side of the guard rail! © 2013 Velo Girl Rides, LLC. All Rights Reserved. Page 3 of 12 How To Fix Your Flat Tire Your wheel consists of a metal (or carbon) rim, connected by spokes to the axle. A tire is mounted on the rim, held in place by two very rigid “edges” of the tire, called beads. Inside the tire is a tube. (there are other types of bicycle wheels, such as tubeless tires, but that is beyond the scope of this document – if you have a different type of set up, learn the specific requirements of repairing flats to your wheel). When you notice your tire is flat, think about what might cause it – because that might affect how successful your repair will be. Possibilities for causing flats include: Tire pressure too low (resulting in a pinch or “snake bite” puncture to the tube); if the inflated tire changes shape when you put your weight on the bike… it is low enough to be vulnerable. We recommend restoring tire pressure at the start of every ride. Cracked/damaged tube at the junction with the valve stem, sometimes due to age and usually indicated by a visually bent and/or loose stem, and the tire frequently found with low pressure at the start of every ride. Glass or other sharp object cutting through the tire, and into the tube, often apparent immediately (sometimes with a bang!). This may cause catastrophic failure of the tire, as well as the tube. Glass or other sharp object picked up miles ago, and eventually working through the tire, not visible on the outside of the tire and causing a tiny puncture in the tube that may leak slowly. Tube damaged during the tube-changing process. Usually realized with loud audible noises made by the cyclist. The following procedures can be followed anytime you get a flat. We recommend you go slow, and be methodical, because if you skip a step… or get clumsy because you’re in a hurry… you may have another flat just a little bit farther down the road, and have to do it all over again. Yuck. 1. Getting Ready You don’t have to flip the bike over upside down in order to work on the wheels, in fact that may damage any computer, lights, bell or other equipment mounted on your bar… and scuff up that seat you love. We recommend keeping the bike upright, but out of dirt/dust/sand. Lean it up against a fence, mailbox, or guardrail is just fine – but be sure you’re well off the road. And if you’re using the guardrail, position the bike on the opposite side. © 2013 Velo Girl Rides, LLC. All Rights Reserved. Page 4 of 12 If you’re taking off the front wheel (see Step #2) then take extra care not to bend or damage the ends of the front forks – set it down gently. If you’re taking off the rear wheel (see Step #3) then take care not to get the rear derailleur in dirt (it has grease, which attracts dirt and sand) and do not rest the weight of the bike on the derailleur, as that could bend it or change the adjustment, which would affect shifting. If we have enough people, we usually ask one of them to hold the bike up, especially when it is a rear wheel repair. 2. Take the Wheel Off The Bike - FRONT Open up the brake shoes, which on most modern road bikes is a little thumb lever on the side of the brake arms, that opens brakes wider – pulling the brake shoes away from the wheel rim.