A lot of you are asking what is a Rowel. (Sometimes also confused for Rowell or Rowal etc.)
The correct spelling is Rowel and it is a sharp-toothed wheel inserted into the end of the shank of a spur.
A spur is a metal tool designed to be worn in pairs on the heels of riding boots for the purpose of directing a horse to move forward or laterally while riding. It is usually used to refine the riding aids (commands) and to back up the natural aids (the leg, seat, hands and voice). The spur is used in every equestrian discipline. There are rules in most equestrian organizations about spur design, use and penalties for using spurs in any manner that constitutes animal abuse.
Spurs is a popular NBA team but I am not sure if Rowel shows up in their logo. Does it?