Lightweight, 4-Way Stretch Mountain Bike Shorts The ultimate in speed and performance, Fox Flexair Shorts are incredibly lightweight and comfortable. Constructed using 4-way stretch fabric, they rapidly wick perspiration and offer enough flex to give you a feeling of freedom unlike any mountain bike short you’ve ever worn. Airflow Zones For Excellent Breathability Strategically placed laser-cut perforations increase comfort further by providing exceptional breathability, while the DWR finish sheds moisture, dirt, and debris as you ride.