BKU / GLOSSARY

112 stable terms, organized by identity.

The glossary is generated from the canonical graph rather than maintained as a second vocabulary. Definitions retain cautions where a term depends on convention or category overlap.

A

Adaptive cycle: Adaptive cycle archetype organized around rider-specific access and mobility.
Aluminum alloy: common bicycle structural material used in frames and components

B

Bicycle commuting: Bicycle commuting considered as a riding environment and set of rider problems, not merely a label.
Bicycle touring: Bicycle touring considered as a riding environment and set of rider problems, not merely a label.
Bicycle trials: Bicycle trials considered as a riding environment and set of rider problems, not merely a label.
Bikepacking: Bikepacking considered as a riding environment and set of rider problems, not merely a label.
BMX: BMX considered as a riding environment and set of rider problems, not merely a label.
BMX bike: BMX bike archetype organized around race or freestyle.
BMX origins in California: The UCI describes BMX as beginning in California in the late 1960s, inspired by motocross and developed through youth bicycle racing on self-built tracks.
Bottom bracket: Provides the rotational interface for the crank spindle or axle within/at the frame
Bottom bracket ↔ crank ↔ frame interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Bottom-bracket drop: Vertical relationship between the wheel axle line and bottom-bracket center, commonly expressed as how far the bottom bracket sits below the axle line.
Bottom-bracket height: Vertical distance from the ground reference to bottom-bracket center for a stated wheel/tire setup.
Brake caliper: Applies pads to a rotor or rim depending on brake architecture
Brake lever: Turns rider hand input into mechanical or hydraulic brake-system input
Brake system: Converts rider control input into decelerating force at a braking interface

C

Cadence: Crank revolutions per minute.
Carbon-fiber composite: used where designers can tailor shape and laminate structure
Cargo bike: Cargo bike archetype organized around utility hauling.
Cargo cycling: Cargo cycling considered as a riding environment and set of rider problems, not merely a label.
Cassette ↔ freehub interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Chain: Transfers tensile drive load between toothed elements in a chain drivetrain
Chain drive: Structured BKU entity.
Chainring: Front toothed element that drives the chain
Chainstay length: Distance from bottom-bracket center to rear-axle center under a stated measurement convention.
Commuter bike: Commuter bike archetype organized around everyday transport.
Crankset: Turns rider pedal input into rotation at the chainring or other drive element
Cross-country MTB: Cross-country MTB considered as a riding environment and set of rider problems, not merely a label.
Cyclocross: Cyclocross considered as a riding environment and set of rider problems, not merely a label.
Cyclocross bike: Cyclocross bike archetype organized around closed-course mixed terrain.

D

Derailleur: Guides chain position among selectable sprockets or chainrings when used in a derailleur system
Derailleur shifting: Structured BKU entity.
Development: Distance traveled per crank revolution in the simplified no-slip gearing model used by BKU Gear Lab.
Dirt-jump bike: Dirt-jump bike archetype organized around jump lines and pump-style terrain.
Disc braking: Structured BKU entity.
Disc rotor: Rotating braking surface attached at the wheel hub in a disc-brake system
Disc rotor ↔ hub interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Downhill MTB: Downhill MTB considered as a riding environment and set of rider problems, not merely a label.
Dropper seatpost: Allows saddle height to be changed while riding when the system is actuated

E

E-bike: E-bike archetype organized around electrically assisted cycling.
Effective top-tube length: Horizontal reference between seat-tube and head-tube/steering references intended to normalize sloping top-tube layouts.
Enduro MTB: Enduro MTB considered as a riding environment and set of rider problems, not merely a label.

F

Fat bike: Fat bike archetype organized around soft or loose surfaces.
Fixed-gear drive: Structured BKU entity.
Folding bike: Folding bike archetype organized around multimodal transport and storage.
Fork: Locates the front wheel relative to the steering axis and frame
Fork offset / rake: Distance describing the front-axle center position relative to the steering-axis line under a stated convention.
Frame: Carries the main structural relationships among rider interfaces, wheels and drivetrain mounting points
Freehub body: Carries a compatible cassette interface while allowing coasting in common hub architectures
Freewheel / freehub coasting: Structured BKU entity.
From hand input to wheel deceleration: Structured BKU entity.
Front center: Distance from bottom-bracket center to front-axle center.

G

Gear inches: A traditional gearing measure computed in BKU Gear Lab as gear ratio multiplied by effective wheel diameter in inches.
Gear ratio: In the simple chain-drive calculation used by BKU Gear Lab, front chainring teeth divided by rear sprocket teeth.
Geometry foundations: Structured BKU entity.
Gravel bike: Gravel bike archetype organized around mixed surfaces.
Gravel cycling: Gravel cycling considered as a riding environment and set of rider problems, not merely a label.

H

Handlebar: Provides hand positions and carries steering/braking/shifting controls
Head-tube angle: Angle used to describe the orientation of the head tube / steering axis relative to the ground plane under a stated convention.
Headset: Provides the bearing interface that lets the steering assembly rotate relative to the frame
Hub: Carries wheel bearings and locates the wheel on its axle interface
Hub ↔ frame/fork axle interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Hybrid bike: Hybrid bike archetype organized around general-purpose paved and light mixed use.

M

Mechanical trail: Horizontal ground-plane distance between the steering-axis intersection with the ground and the tire contact-point reference in a simplified bicycle geometry model.
Mountain bike: Mountain bike archetype organized around trails.
Mountain biking: Mountain biking considered as a riding environment and set of rider problems, not merely a label.
Mountain-bike origins in 1970s California: The UCI describes mountain biking as widely acknowledged to have origins in 1970s California, with riders modifying and racing bicycles on Marin County mountain tracks.

O

Ordinary / high-wheel bicycle: By the early 1870s wire-spoked high-wheel bicycles were established; the Smithsonian describes James Starley introducing the Ariel in 1871 and the form later becoming known as the Ordinary.

P

Pedal: Provides the foot interface through which rider force enters the crank
Pedal ↔ crank interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Pneumatic bicycle tire, 1888 evidence: The Science Museum Group catalogs a Dunlop pneumatic cycle tyre dated 1888; Smithsonian history places Dunlop’s pneumatic-tire patent soon after the rise of the Safety bicycle.
Pneumatic tire support: Structured BKU entity.

R

Reach: Horizontal frame reference from the bottom-bracket center to a defined upper head-tube/steering-axis reference point under common geometry conventions.
Rear shock: Spring/damper unit used within a rear-suspension linkage or frame system
Rear sprocket / cassette: Provides one or more rear toothed ratios for a chain drivetrain
Recumbent bicycle: Recumbent bicycle archetype organized around seated or reclined rider position.
Rim: Supports the tire and anchors spokes in a conventional tension-spoked wheel
Rim braking: Structured BKU entity.
Road bike: Road bike archetype organized around paved riding.
Road cycling: Road cycling considered as a riding environment and set of rider problems, not merely a label.
Rolling resistance: Energy loss associated with rolling deformation and contact processes; it depends on more than tire width or pressure alone.

S

Saddle: Supports the rider at one contact point
Safety bicycle transition: Smithsonian history describes Safety bicycles gaining popularity with two smaller wheels of similar size, chain drive and gearing, as designers sought safer alternatives to the Ordinary.
Seat-tube angle: Angle describing the seat-tube axis relative to a ground/horizontal reference under a stated convention.
Seatpost: Positions the saddle relative to the frame
Shifter: Provides rider input to a gear-changing mechanism
Sourced historical turning points: Structured BKU entity.
Spoke: Links hub and rim in a tension-spoked wheel
Stack: Vertical frame reference from the bottom-bracket center to a defined upper head-tube/steering-axis reference point under common geometry conventions.
Standover height: Ground-to-frame height measured at a stated point on or near the top tube.
Steel: widely used bicycle structural material with many alloys and construction methods
Steerer ↔ headset ↔ frame interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Steering rotation: Structured BKU entity.
Stem: Connects handlebar to steerer or steering structure
Stem ↔ handlebar interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Suspension fork: Combines steering/wheel location with controlled suspension travel
Suspension spring + damping: Structured BKU entity.

T

Tandem bicycle: Tandem bicycle archetype organized around two or more riders in-line.
Tire: Provides the bicycle-ground contact envelope and contains or supports inflation depending on system
Tire pressure: Internal inflation pressure in a pneumatic tire system; appropriate values depend on the complete tire/rim/load/use case.
Tire ↔ rim interface: This is an interface checklist, not a compatibility declaration. Exact manufacturer documentation controls specific fit.
Titanium alloy: used in some frames and components where corrosion resistance and strength-to-mass goals are valued
Touring bike: Touring bike archetype organized around distance with luggage.
Track bike: Track bike archetype organized around velodrome.
Track cycling: Track cycling considered as a riding environment and set of rider problems, not merely a label.
Trail mountain biking: Trail mountain biking considered as a riding environment and set of rider problems, not merely a label.
Triathlon / time-trial bike: Triathlon / time-trial bike archetype organized around aerodynamic solo efforts.

W

Ways to move one bicycle: Structured BKU entity.
Wheel: Supports the tire and rotates about the hub axle
Wheelbase: Distance between front and rear axle centers.
Where the bicycle touches the world: Structured BKU entity.
Wood / laminated wood: historically and experimentally used in some bicycle structures

ICU / CONNECTED DISCOVERY

Continue through related ideas.

These are bounded editorial connections; paid placement does not influence them.

Loading public connections…

See reverse connections