- What it is - Metal chain regulator with a spring chain tensioner designed to keep your chain taut and running smoothly. - Size: 35 (small). Lightweight and easy to carry. Metal construction for long-lasting use. - Key benefits — why you need it - Prevents chain sagging and reduces the risk of chain derailment, improving riding safety and reliability. - Spring-loaded tensioning maintains consistent chain tension through bumps and gear changes, reducing wear on chain and sprockets. - Compact and lightweight design makes it practical to install on small frames and to carry as a spare for field repairs. - Main features - Durable metal material for strength and longevity. - Spring chain tensioner mechanism for automatic, consistent tension adjustment. - Compatible with 415 chains. - Suitable for BMX, e-bikes, and most foldable bicycles and bicycle tools. - Compatibility and performance - Functions as a BMX chain tensioner to eliminate sag and provide safer riding. - Works as an e-bike accessory for foldable and compact bicycle platforms that require a reliable tensioning solution. - Small footprint (35) fits tight frame spaces while delivering dependable tension performance. - Practical use scenarios 1. Commuter with a foldable e-bike: installs the metal tensioner to maintain chain tension after repeated folding/unfolding and to reduce chain noise and wear during daily rides. 2. BMX rider or small-frame bike owner: uses the tensioner to prevent chain sag and minimize the chance of chain drop during tricks or rough terrain. 3. Portable repair kit: carries the small, lightweight 35 tensioner as a reliable spare for on-the-road chain tension issues or temporary fixes. - Why choose this tensioner - Straightforward function: spring-loaded metal regulator that keeps chains at the correct tension. - Clear compatibility: intended for 415 chains and for use with BMX, e-bike, and most foldable bicycles. - Practical size and material: small, metal, and easy to carry without sacrificing durability or performance.