Q: Why are leather jacket sleeves so long?

A: A leather motorcycle jacket has sleeves that are designed to be much longer than a casual-wear leather jacket to protect the rider’s arms while extended. For most casual wearers, the ideal length for leather jacket sleeves is somewhere between the wrist and half-inch below the wrist. 

A properly designed leather jacket doesn’t need extra long sleeves to make up for poor mobility. Some jackets were designed to be rolled up, and there will be buckles and buttons at the end to hold the leather jacket in place once it’s rolled up.

— Kevin Freeman, Leather Craft Garage