Layup Schedule
Summary A layup schedule is a detailed plan that defines the number, orientation, and placement of composite fiber layers—typically carbon fiber—used in a bicycle frame or component. It…
Velopedia Entries
An evolving encyclopedia of cycling brands, technologies, components, and history.
Bladder Molding
Summary Bladder molding is a composite manufacturing process used to create hollow carbon fiber structures, most notably bicycle frames and forks. It uses an inflatable bladder inside a…
Resin Transfer Molding (RTM)
Summary Resin Transfer Molding (RTM) is a closed-mold composite manufacturing process that injects liquid resin into a mold cavity preloaded with dry fiber reinforcements. It offers excellent control…
Universal Derailleur Hanger (UDH)
Summary The Universal Derailleur Hanger (UDH) is a standardized derailleur mounting interface introduced by SRAM to simplify rear derailleur hanger compatibility across frame brands. It reduces the complexity…
I-Spec
Summary I-Spec (Integration Specification) is Shimano’s integrated mounting system that allows compatible shifters and brake levers to share a single clamp on the handlebar. Developed to streamline cockpit…
Boost Spacing
Summary Boost Spacing is a hub and drivetrain standard introduced to widen axle widths, increase spoke bracing angles, and improve frame stiffness and tire clearance. First launched in…
Direct Mount Chainring
Summary A direct mount chainring is a front chainring that attaches directly to a crank arm interface without using a separate spider or bolt circle. This system simplifies…
Narrow-Wide Chainring
Summary A narrow-wide chainring is a chain retention solution that alternates narrow and wide teeth to match the inner and outer links of a bicycle chain. It’s designed…
Hyperglide
Summary Hyperglide is Shimano’s original cassette ramping technology that dramatically improved indexed gear shifting in multi-speed drivetrains. First introduced in the late 1980s, Hyperglide was designed to enable…
Hyperglide+
Summary Hyperglide+ is Shimano’s next-generation shifting technology developed to improve chain engagement, gear transitions, and drivetrain performance under load. It allows riders to shift both up and down…
Head Tube Angle
Summary Head tube angle refers to the angle between a bike's head tube and the ground, measured in degrees. It's a defining aspect of bicycle geometry that directly…
Axle-to-Crown
Summary Axle-to-crown is a measurement used in bicycle design to indicate the vertical distance from the axle of a fork to the top of its crown. It plays…