Cycling Glossary

Plain-English definitions for the maintenance, training, bike-fit, and data terms used inside Velo Buddy. Bookmark this page — it's the cheat sheet we wish every cyclist had.

Maintenance

Terms used across Velo Buddy's maintenance tracking, smart reminders, and component wear engine.

Adaptive service reminder
A notification that fires based on actual ride data (distance, terrain, weather, intensity) rather than a fixed calendar. Velo Buddy's reminders adjust when you ride more, less, or in tougher conditions.
Component wear
The cumulative degradation of a bike part from use. Velo Buddy estimates wear per component using mileage, elevation, weather, and rider intensity.
Drivetrain
The collection of parts that transfer your pedalling into forward motion — chain, chainrings, cassette, derailleurs, bottom bracket, and pedals.
Chain wear (0.5% / 0.75%)
A measure of how much a chain has stretched. Road riders typically replace chains at around 0.5% stretch to protect the cassette; mountain bike drivetrains tolerate slightly more.
Chain waxing
A drivetrain lubrication method using hot paraffin wax instead of drip lube. Reduces friction and contamination; requires re-waxing every 200–300 km.
Cassette
The cluster of sprockets on the rear wheel. Wears out more slowly than the chain, but faster if you run a worn chain.
Chainring
The front gear(s) attached to the crankset. Worn chainrings cause the chain to skip under load.
Bottom bracket
The bearing assembly inside the frame that the crankset spins on. Service interval depends on seal quality and riding conditions.
Brake pads
The friction material that presses against a rim or rotor to slow the bike. Check monthly; replace before the wear indicators are reached.
Rotor
The metal disc on a wheel hub that disc brake pads clamp onto. Replace when below the minimum thickness stamped on the disc (typically 1.5–1.8mm).
Hydraulic bleed
The process of replacing the fluid in hydraulic disc brakes. Restores lever feel and braking power. Generally done once per year.
Tyre wear indicator
A small dimple, stripe, or groove on a tyre that disappears as the tread wears down, signaling it's time to replace.
Bearing service
Cleaning, re-greasing, or replacing bearings in the hubs, headset, or bottom bracket. Intervals vary with weather exposure.
Cost per kilometre
A Velo Buddy analytics metric: total cost of a component divided by kilometres ridden on it. Useful for comparing tyres, chains, or service shops.
Logbook
A full chronological record of every service and part replacement for a bike. Premium users can export the logbook to PDF for resale or warranty claims.

Training

Terms used by Velo Buddy's AI Training Coach and workout export.

FTP (Functional Threshold Power)
The highest average power a rider can sustain for about an hour, measured in watts. Used to define training zones in structured workouts.
Power zones
Ranges of power output (as percentages of FTP) used to structure workouts — typically Z1 (recovery) through Z7 (neuromuscular).
Heart rate zones
Ranges of heart rate (as percentages of max HR or threshold HR) used as an alternative to power for structuring training.
RPE (Rating of Perceived Exertion)
A 1–10 subjective effort scale. Useful when a rider doesn't have a power meter or heart rate monitor. Velo Buddy's coach can plan by power, HR, or RPE.
Structured workout
A session with explicit intervals, targets, and rest periods — for example 4 × 8 minutes at 95% FTP with 4-minute recoveries.
Intervals
Short hard efforts separated by recovery periods. Form the backbone of most structured training plans.
Periodisation
Organising training into blocks — base, build, peak, recovery — so fitness rises progressively without overtraining.
TSS (Training Stress Score)
A single number summarising the load of a ride, combining intensity and duration relative to FTP.
CTL / ATL / TSB
Chronic Training Load (fitness), Acute Training Load (fatigue), and Training Stress Balance (form). The standard performance-management chart metrics.
ZWO file
An XML workout format used by Zwift. Velo Buddy exports every coach-generated workout as a ZWO file.
FIT file
A compact binary format used by Garmin, Wahoo, Hammerhead, and most head units for workouts and activities. Velo Buddy exports workouts as FIT files.
Workout push
Sending a structured workout directly to a connected account (Garmin Connect, Wahoo, TrainingPeaks) via OAuth, so it appears on the head unit without manual file transfer.

Bike fit

Terms used by Velo Buddy's AI Bike Fit video analysis.

Saddle height
The distance from the centre of the bottom bracket to the top of the saddle along the seat tube. One of the highest-impact fit measurements.
Reach
The horizontal distance from the bottom bracket to the centre of the head tube top. Combined with stack, it describes frame fit independent of stem length.
Stack
The vertical distance from the bottom bracket to the top centre of the head tube. Higher stack = more upright position.
Knee angle
The angle at the knee joint at the bottom of the pedal stroke. A common target range is 140–150°; too straight risks injury, too bent wastes power.
Hip angle
The angle between the torso and thigh at the top of the pedal stroke. Closely tied to saddle fore/aft, stem length, and drop to the bars.
Setback
How far the saddle sits behind the bottom bracket. Affects knee-over-pedal-spindle (KOPS) and hip rotation.
Cleat position
Where the pedal cleat is mounted under the shoe. Affects knee tracking, hotspots, and Achilles loading.
Drop (handlebar drop)
The vertical difference between saddle height and handlebar height. Larger drop = more aerodynamic, less comfortable over long rides.

Tyres and pressure

Terms for Velo Buddy's tyre pressure calculator and tyre analytics.

Rolling resistance
The energy lost to tyre deformation as it rolls. Lower pressure and softer compounds typically reduce rolling resistance on rough roads up to a point.
Tubeless
A tyre system that seals to the rim without an inner tube, using liquid sealant. Allows lower pressures and better puncture resistance.
Clincher
A traditional tyre that uses an inner tube inside a tyre with beads that hook onto the rim.
Tyre pressure (PSI / BAR)
Air pressure inside the tyre. Velo Buddy's calculator recommends pressures based on rider weight, tyre width, surface, and tubeless vs tubed setup.

Data and integrations

Terms that describe how Velo Buddy syncs, stores, and analyses your cycling data.

Strava
A cycling and running social platform. Velo Buddy connects via OAuth to import rides and track gear usage.
Ride with GPS (RWGPS)
A route-planning and activity-tracking platform. Velo Buddy imports RWGPS rides and infers bike usage, since RWGPS doesn't expose a separate gear API.
Webhook
A server-to-server notification used by Strava to tell Velo Buddy's backend when new activities are posted, so rides sync without the app being open.
OAuth
The authorisation protocol used to connect accounts (Strava, Ride with GPS, Garmin, Wahoo, Hammerhead, TrainingPeaks) without sharing passwords.
AI consent
Explicit in-app permission required before Velo Buddy sends any of your data to its AI providers (Anthropic, Google). Can be revoked any time in settings.
On-device
Data that stays on your phone and is not uploaded to servers. Velo Buddy keeps AI chat history on-device.