Recently, when I removed my tractor tires from the rims so I could replace the rusted rims, I found that breaking the bead was exceptionally difficult, primarily due to corrosion caused by calcium chloride. After attempting other methods (wedges, etc..) I solved the problem by making a simple DIY bead breaker using nothing more than a length of wood 4x4 post and two short lengths of scrap wood.
The DIY bead breaker was constructed by securing one two foot length of scrap wood to the wall of my garage about 18 inches off the floor, before placing the tire and rim beneath it. A six to eight foot length of 4x4 post was then laid across the tire and positioned so that the end of it was beneath the length of scrap wood previously secured to the wall. The remaining short length of wood (about 12 inches long) was positioned and temporarily held so that the edge of it (cut on a slight angle) rested against the tire/rim interface (the bead), before lifting the 4x4 post and placing it across the short length of wood (held against the bead) and ensuring that the end of the 4x4 post was positioned under the edge of the piece of wood previously secured to the wall.
After the bead breaker is positioned, one simply applies pressure at the end of the 4x4 post to break the bead, rotating the tire slightly and repeating as necessary. Note that the whole process of assembling or positioning the DIY bead breaker sounds complicated in writing, but the reality of it is extremely simple.
The DIY bead breaker uses an engineering principal known as force amplification, where one end of a lever is placed on or against a fulcrum and a small force is applied to the other end, generating a large force at a point very close to the fulcrum. In this case, the lever used is classified as the second of three types or orders of levers. A wheelbarrow is a simple example of a second-order lever.
First-order levers:
- the fulcrum is positioned between the effort and the load
- the effort is smaller than the load
- the effort moves further than the load
- the lever can be considered as a force magnifier
Second-order Levers:
- the effort and the load are positioned on the same side of the fulcrum but applied in opposite directions
- the load lies between the effort and the fulcrum
- the effort is smaller than the load
- the effort moves further than the load
- the lever can be considered as a force magnifier
Third-order Levers:
- the effort lies between the load and the fulcrum
- the effort is greater than the load
- the load moves further than the effort
- the lever can be considered as a distance magnifier
Using the formula "
F*L=W*X" or "
F=(W*X)/L" one can easily determine what any force being applied at the end of the lever will yeild at the point where the resistance or weight is being overcome. In the formula F is the force applied at the end of the lever, W is the weight or resistance being overcome, L is the length of the lever between the fulcrum and the point where the force is being applied, and X is the distance between the fulcrum and the weight or resistance being overcome.
For example: If the lever was 8 feet long and the resistance (the bead) was 1 foot from the fulcrum, applying 25 pounds of force at the end of the lever would yield 200 pounds of force at the point of resistance (the bead), effectively magnifying the applied force by a factor of four. In other words... 25=(200*12)/96
As you can see from the images in my previous post, the DIY bead breaker works like a charm.
