FOX offers you its Adult Off-Road Pants, the 180 ATLAS:

Material:

• Made from 600D polyester for good durability and resistance
• Leather panels inside the knee protecting against engine heat and abrasion resistant
• Four-way stretch woven inserts on the knees, at the back and in the crotch for optimal freedom of movement
  

The "+" :

• RAP cut (attack riding position) for a precise fit on the bike
  
• Stretch panels around the knee providing flexibility to accommodate knee guards
• Stretch panel at the back of the pants below the waist and in the crotch provides better comfort in riding position
• Pre-shaped design for a perfect fit in riding position
• Premium screen-printed graphics