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julio 22, 2026

Bike Steerer Extender Quill Stem Adaptor 21.1mm 230mm Steel Silver Commuter Cafe

In great condition for its age. Fits 21.1mm quill stems to threadless setup of a 21.1mm Stem. Very rare hard to find item. Top to bottom flat 230mm length for that extension. Our sales have provided funding to give away over 13,000 bikes, divert 1000 tons from the landfill, and teach repair skills to over 7000 people.
julio 22, 2026

ALLOY 13/16″ 21.1MM OS BMX BIKE 4BOLT QUILL STEM VINTAGE SCHWINN CRUSIER BICYCLE

ALLOY 13/16" 21.1MM OS BMX BIKE 4BOLT QUILL STEM VINTAGE SCHWINN CRUSIER BICYCLE Quill Diameter: Compatible with standard quill stems, the 21.1 mm diameter works seamlessly with most bicycles, especially older or vintage models.Bar Clamp Diameter: Designed to fit standard 21.1 mm handlebars, making it adaptable for BMX and other bikes that require secure handling.Stem Length: At 55 mm, this stem strikes a balance between control and responsiveness, ideal for BMX riding where quick maneuvers are key.Quill Length: A 4-1/4 inch (108 mm) quill length provides a stable fit within the fork's steering tube, ensuring secure support.Fork Compatibility: Suited for 1-inch forks, this stem covers a range of BMX and vintage bike styles that use this standard size.Angle: The 0-degree extension allows for a straightforward alignment from the steerer tube, promoting an assertive riding stance.Material: Crafted from high-grade alloy, this stem combines strength and low weight, resisting corrosion for long-lasting use.BMX-Specific Design: Built for the demands of BMX, this stem stands up to jumps, tricks, and high-impact use, meeting the needs of both casual and serious riders.Installation: Easy to install—simply insert the quill into the steerer tube and tighten the bolt to secure. Ensure the handlebar is centered and aligned with the front wheel before finalizing. Benefits: This 450 Alloy Stem is engineered for BMX riders seeking dependable performance in a lightweight, durable design. Its versatility and compatibility with standard parts make it a practical choice for both vintage bike enthusiasts and BMX riders alike. Copyright © 2024 Cycle Source. All rights reserved.
julio 22, 2026

Porkchop BMX 21.1mm quill chromoly CR-MO threadless stem adapter for 1″ threaded

Porkchop BMX quill stem threadless stem adapter - made of chromoly steel. This adapters allows you to run a 1 1/8" threadless stem on your old school BMX bicycle (with 1" threaded fork that uses a 21.1mm quill stem) * Color: CHROME * Material: 4130 chromoly steel * Length: Overall 171mm - maximum rise from minimum insertion mark to top of stem mounting is 88mm. * Stem requirements: Uses a 1 1/8" threadless stem not thicker than 40mm where it attaches. * Quill size: 21.1mm (this is common for 1980's BMX bicycles, however a very similar common stem size is 22.2mm which this will not work for. You must carefully measure the inside diameter of your fork steer tube to be sure which size stem quill your fork requires) * Includes hollow Potts Mod bolt to allow for brake cables to be run inside of fork steer tube if desired.