There are two main options for tensioning a spinning wheel: double drive or scotch tension---also known as single drive. Knowing how to use both systems is a practical skill for any spinner to have. On an Ashford Traveller, the double drive wheel allows for the spinner to alternate between the two, while the single drive wheel allows only for scotch tension. Beginning spinners often prefer scotch tension because it's easier to control and understand than double drive tension. It also creates a softer, less tightly spun yarn, which beginning spinners---who often have issues with over-spun yarn---also appreciate.
Remove the drive band from the bobbin whorl by lifting it out of the groove with your fingers and place it with the band on the spindle---or flyer--- whorl. To get the drive band to reach to the spindle whorl, you may have to loosen the drive band tension by unscrewing the drive band tension knob located on the maiden bar. Skip this step if you are using the scotch tension version of the Ashford Traveller.
Unwind the scotch brake from around the back upright maiden.
Place the scotch brake band around the top of the bobbin whorl, making sure the spring is attached to the hook on the left side of the mother-of-all.
Insert the tension knob at the opposite end of the tension brake in the hole on the right side of the mother-of-all.
Tighten slightly by twisting the brake band around the knob, making sure the spring is stretched slightly, but not overly so. It should not be so tight that the entire spring is pulled apart but not so loose that it is not extended at all. The brake band should give slightly when you place a finger on it, as an elastic hair band would if it were stretched between your forefinger and thumb, and you tested the give with your opposite finger.
Treadle a few times to ensure the tension is correct on your leader or ply, loosening or tightening the knob as needed by wrapping or unwrapping the brake band from the knob. Correct tension is achieved when the wheel draws the ply in smoothly as you feed it, not winding back on itself or pulling the ply forcefully out of your hands. You should not have to work against your wheel to get the ply where you want it to go.
As you spin, the wheel's movements can loosen the tension, especially on older wheels. Simply re-tighten the knob, or if it happens very frequently, replace the knob. For spinning very fine yarn, switch the band placements, putting the drive band on the bobbin whorl and the scotch brake on the spindle whorl. This reduces the ratio severely, creating a very fine yarn.