Bicycle Handlebar Shim pair Clear purpose and benefit Designed to reduce the handlebar diameter from 4mm to 31.8mm to enable compatibility with different stem sizes. Helps you adapt existing handlebars to a wide range of stems, simplifying upgrades and repairs. Materials and durability Made of aluminum alloy for durability and a secure locking mechanism. Aluminum construction offers longer lifespan and reliability compared with plastic alternatives. Installation and use Simple, hassle installation: buckles directly into the handlebar installation position for fast setup. No complicated tools required and no complex procedures. Safety and performance Robust aluminum alloy construction contributes to safer, more reliable rides. Consistent clamping performance helps maintain control and stability. Key attributes Function: converts and adapts handlebar diameter to fit different stems Compatibility: suitable for handlebars requiring adaptation to 31.8mm Size options: designed to reduce from 4mm to 31.8mm Material: aluminum alloy Performance: durable, secure fit with improved lifespan over plastic options Practical use scenarios Upgrading a road or mountain bike with a stem that requires a different clamp size, ensuring a secure fit without replacing the bar. Rebuilding a bike after changing to a stem with a larger or smaller clamp diameter, preserving compatibility with existing handlebars. DIY bike maintenance or custom builds where quick and reliable adjustment of handlebar diameter is needed for a secure, longlasting fit.