At this time, the Glossary has been done to explain terms in the “Primary Concerns.” chapter that may not be familiar to those new to mountain biking. We have not provided a detailed account of scientific terms in the later sections because of time constraints. We hope that those venturing into these sections will have adequate prior knowledge or know how to obtain such knowledge from more fundamental sources, or that the bold-written essential information will suffice to give a reasonable understanding. In the future, we hope to provide a more detailed account of scientific terminology.
Bob (suspension):
The tendency of a suspension to oscillate under pedaling from cyclic forces in the chain.
Bottom Bracket (BB):
The Bearing and axle mechanism supporting the cranks.
Coasting:
Riding ones bike while neither pedaling nor braking.
Cross-Country (XC):
A style of riding (bike) that involves all types of terrain – uphill, downhill, and technical riding.
Downhill (DH):
A style of riding (bike) that involves almost exclusively downhill terrain. Riders often use cars or ski lifts to get them to the top of the hill.
Equilibrium (suspension):
See “Sag”.
Feedback (bump):
The tendency for the cranks to rotate backward due to an increasing chain length as the suspension compresses (due to a hitting bump for example).
Floating brakes:
Rear disc brake mechanisms in which the brake is mounted on its own linkage arms, which are not part of the load bearing rear suspension components. These mechanisms can give mono-pivots a braking character similar to those found on some 4-bars.
Freeride:
A style of riding (bike) that involves most of the same terrain as cross-country, but with an emphasis on downhill and more aggressive maneuvers such as jumps or drop-offs.
Full Suspension Frame:
A frame that allows the rear wheel to move with respect to the rider. Usually this is accomplished through a system of levers supported by a spring or shock.
Geometry (frame or suspension):
The spatial configuration of frame members, pivots, and other components that make up a bicycle frame or suspension.
Horst Link:
Sometimes used to describe multi-link suspensions with lower rear pivots on the chain stays. Named after Horst Leitner of the now defunct Amp Bicycles, who patented a certain chain stay pivot location now owned by Specialized.
Kickback (bump):
See “Feedback”.
Main Triangle:
In common non-URTs, defined by the seat, handlebars, and bottom bracket. In a URT, may also refer to the frame member defined by the handlebars and the seat.
Main Pivot:
The lowest and most forward of the pivots in any suspension mechanism. Responsible for handling the highest amount of side loading in the mechanism.
Mono-pivot:
A type of full suspension frame in which the suspension consists of a single arm or triangle, rotating about the main pivot.
Neutral Geometry:
Describes a suspension frame, configured such that the components do not move relative to one another during some action by the rider (usually pedaling or braking). A suspension will be neutral if a zero torque balance is maintained about its pivots in the presence of a particular action.
Qualitative:
Examination involving attributes, characteristics, properties, and other such “qualities, usually making little or no use of hard numbers.
Quantitative:
Examination involving hard numbers to describe relevant “quantities”.
Rate:
See “Suspension Rate”.
Sag (suspension equilibrium):
The position a suspension assumes when a rider sits on the bike but performs no action.
Soft-tail:
A limited-travel suspension design, typically with about 1.5 inches of travel, which has a shock, but no pivots. The frame material is usually titanium.
Squat:
The tendency of a suspension to compress during a pedal stroke, due to rider inertia. As the rear wheel rolls forward during the pedal stroke, the rider's mass will resist movement, causing the compression.
Suspension Rate (also “Spring Rate” or just “Rate”):
A function describing the force with which a spring will tend toward equilibrium at each point of compression or extension away from equilibrium.
Suspension Member:
The structural pieces of the suspension. In a mono-pivot, the swingarm is the only suspension member. In a 4-bar, the swingarm, rear link (seatstay link), and upper link comprise the suspension.
Swingarm:
The arm in any suspension mechanism that rotates around the main pivot.
Torque Balance:
The torque differential between two objects rotating around a common pivot. A torque balance of zero under some action means that the two objects form a neutral mechanism under that action.
Travel:
The vertical distance a suspension will move the rear wheel axle.
Type (suspension):
Various rear suspension classifications, defined for some propose, ex. 4-bar, mono-pivot, Horst link...
URT:
A type of mono-pivot full suspension frame in which the crank is mounted on the swing arm