The Spoke Curriculum - Session 2
Tire & Tube Service
Description
Demo of changing a flat
Details
Explanation of tire, tube, rim (i.e. wheel anatomy), proper pressure & the fact that tubes aren't air-tight. Have sample tubes so people can practice hands-on.
Content
| Primary Content | Instructor Notes |
|---|---|
| The wheel of a bike consists of the hub, the spokes, the rim, the tube, and the tire. The spokes hold the rim to the hub, and keep it straight through tension. The tire mounts on the rim, and the inner tube goes inside the tire. The tire is held in place through air pressure in the tube. The recommended pressure of the tube is usually written on the side of the tire: you should generally inflate a tire to the maximum recommended pressure. Once you have a tire inflated, squeeze it so you get a feel for what proper pressure should be. It should be quite firm. Keeping the proper pressure helps to avoid flats (if your pressure is too low, you can get "pinch flats", from the tube being pinched against the rim when you hit a curb or bump), and makes the ride much faster and easier.
Tubes are made of a rubber that isn't air-tight. So tires lose air pressure over time, even if they don't have any holes. This is normal, and means that you should check and re-inflate your tires every few weeks. If you do get a flat, it's usually due to a hole in the tube (not the tire: often, there's no damage at all to the tire). You can usually patch the puncture with a patch, which costs 25 cents. Patching a tube is a permanent fix: it's as good as new if done correctly. Some times the valve itself fails, or starts to break away from the tube. In this case, a patch won't work, and the tube should just be replaced. To fix a flat, put your bike in a bike stand. If you don't have a bike stand, lie the bike on its left side (non-drive side). Never lie the bike on its rear derailleur, nor sit the bike upright on its rear derailleur, as this can very easily damage it. Please refer to http://www.parktool.com/blog/repair-help/tire-and-tube-removal-and-installaton for full instructions on removing wheels, tires and tubes, checking for damage, and replacing tubes, tires, and wheels. Quick-release skewers must be fully-closed. Tighten the adjusting nut of the skewer so that when you close the lever, it meets resistance halfway through the swing. It should take a fair amount of force to fully close the lever (not superhuman strength, though). If the lever isn't closed all the way, it can open up from vibrations while riding, and the wheel could fall out. When the lever is fully closed, it will tend to stay closed from vibrations. |
Specific Skills
| Skill | Content | Reference |
|---|---|---|
| Tire and Tube Removal and Installation | http://www.parktool.com/blog/repair-help/tire-and-tube-removal-and-installaton | |
| Inner Tube Repair | http://www.parktool.com/blog/repair-help/inner-tube-repair |
Description
Details
Content
| Primary Content | Instructor Notes |
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