Flat repair is absolutely a must know repair for any cyclist. If you learn how to do any maintenance on your bike it should be how to change a flat tube.
You will need the following for this repair:
- Tire levers
- Patch kit
Super human strength
The first step in repairing a flat is to remove the wheel. Most modern bicycles have their wheels attached with a quick release mechanism which makes their removal tool-less and easy. Before removing the wheel, The lever on the side of the brake should first be opened to increase clearance so the tire can fit between the brake pads. The fork usually has a tab system that will require loosening the quick release skewer by winding the end opposite the lever off a little. It is not necessary to remove this completely.
Once the wheel has been removed from the bike, open and press on the valve to release any air still left in the tire. Also work your way around the tire, pressing the sidewall in towards the center to release the bead from the rim. This will make the removal much easier.
Place a tire lever underneath the bead and align it with a spoke. It is best to start at a location that is not near the valve stem. Repeat this by placing up to two more levers. They should line up with the next closest spoke. Once all the levers are in place, you can now begin to pull them down towards the hub. Each lever has a hook on its end that can be attached to a spoke to hold it in place. By the time you reach the last lever, one of the tire beads should be easily coming off the rim. It is not necessary to remove the second bead to replace the tube.
Remove the damaged tube and prepare the replacement by first adding some air to it. There should be just enough air in the tube so that it holds its shape but not enough so that the tube expands. This will prevent damaging the tube. You can now begin to install it by first placing the valve in the valve hole and working towards the opposite end of the rim. You should push the tube into place in the following stages.
- Tube inside tire
- Tube inside rim
- Bead inside rim
Failure to complete one stage before beginning the next increases the chance that you will pinch and damage the tube.
Reinserting the tire bead into the rim has to the be least favorite step in the flat change process. Starting at the valve stem, you work your way around the tire, pushing the bead into the rim. Most riders will have no problem with this up until the last few inches.
Once the bead has been completely moved into the rim, do not forget to push the valve stem in towards the tire before airing. The tube can get caught underneath the bead near the valve, causing the tire to blow off the rim right near the valve. Pressing the valve in will prevent this from happening.
Categorised in: Bike
This post was written by Tom