Spoke butted (double or even triple) to reduce weight while maintaining strength. A variation on the wire-spoked wheel was Tioga's "Tension Disk", which appeared superficially to be a solid disk but was in fact constructed using the same principles as a normal tension-spoked wheel. Instead of individual wire spokes, a continuous thread of Kevlar (aramid) was used to lace the hub to the rim under high tension. The threads were encased in a translucent disk for protection and some aerodynamic benefit, but this was not a structural component. Wire spokes can be radial to the hub but are more often mounted
Bicycle wheel Brass nipples are heavier than aluminum, but they are more durable. Aluminium nipples save weight, but they are less durable than brass and more likely to corrode. A nipple at the rim of a wheel usually protrudes from the rim towards the center of the wheel, but in racing wheels may be internal to the rim, offering a slight aerodynamic advantage. A wheel can be formed in one piece from a material such as thermoplastic (glass-filled nylon in this case), carbon fiber or aluminium alloy. Thermoplastic is commonly used for inexpensive BMX wheels. They have a low maximum tire pressure