The Bicycle/ Compact Utility Club from Blue Monster Prep is great for securing bikes and thousands of other items.  

Features

• Extra heavy duty construction withstands over 1,500 lbs. of pressure
• Easy to use
• Weather Resistant
• Replaces Chains & Padlocks
• Fully adjustable to eliminate "dead space" within the lock
• Vinyl Coated
• Cro-moly Steel
• Fits 3/8" chain
• Comes with 4 keys