Part of being a serious cyclist is dressing the part, not just for looks but for comfort and functionality. You never see a serious cyclist wearing long pants that aren’t form fitting. Loose clothing is less aerodynamic slowing the rider down, it’s not as comfortable for this activity and most importantly long pants can get caught in the chain. bike jerseys should be form fitting too, but not too tight as you want to be able to move comfortably while cycling.

Bike jerseys are designed to be a little longer in the back so they fit better while in the riding position. They are also made with materials that help wick moisture away from the body and keep you at least a little cooler. Many biking shirts have vents to help with cooling or full/partial zippers in front and are made of microfibers to help keep you more comfortable.