SINGLE PLY CASING
One layer of nylon wrapped from bead to bead, a single ply conforms well to the terrain and is lighter weight.
DUAL PLY CASING
Two pieces of casing are used from bead to bead which provides additional protection in Downhill applications.
A sturdy material is needed to hold the tire against the rim when inflated. Wire is used to ensure the bead will not expand, but wire is also heavier.
Foldable beads also stay tight to the rim but are lighter weight and easier to transport. The bead is made of an Aramid or Kevlar material.
CARBON FIBER BEAD
A flexible material with greater strength to withstand the high pressure rating of a road tire.
THREADS PER INCH (TPI)
The number of nylon threads that cross through one square inch of the tire’s casing. Lower TPI gives better puncture and tear resistance, but is heavier. Higher TPI conforms more to the terrain, offering a smoother, more supple ride. It is also lighter weight.
Maxxis TPI ratings are the threads-per-inch of a single casing ply, as compared to some competitor TPI ratings.