Velopedia’s specification analysis is a reading aid for the Bicycle Archive. It takes details such as cassette tooth counts, wheel labels, frame material, brake type, and suspension equipment, then explains a relationship or inspection consequence that isn’t obvious from a parts list alone. It is not a review score, fit recommendation, appraisal, or report on the condition of a particular bicycle.
The most important label is “Derived from the archived manufacturer record.” The analysis starts with the specifications preserved for that model and build. Some cards restate a published fact in a more useful form; others calculate or normalize information from two or more fields. None of them establish what is currently installed on a used bike.
Read the page in three layers
An Archive page contains three different kinds of information. Keeping them separate prevents most misreadings.
1. The archived specification
The specification tables preserve model-year information such as the frame, fork, drivetrain, brakes, wheels, tires, sizes, colors, geometry, weight, and original MSRP when those details are available. This is the evidence layer.
Specifications can vary by country, frame size, production run, or later substitution. A used bicycle may also have years of replacement parts. The record identifies the documented build; it does not certify that a bicycle remains original.
2. A calculation or normalization
Velopedia may calculate cassette range from published tooth counts, map a familiar wheel name to its ISO bead-seat diameter, or group varied manufacturer language into a broad frame-material or brake family. This makes unlike catalog descriptions easier to compare.
The calculation should be reproducible from the fields shown on the page. Normalization is broader: it organizes source wording without pretending that every product in the category is interchangeable.
3. The practical meaning
The short explanation beneath a card says what the data changes for a buyer, owner, or mechanic. A carbon-frame label changes the inspection emphasis. A press-fit bottom bracket raises more compatibility questions than the words “press fit” answer. A tubeless-ready label says something about the equipment’s capability, not how the tires are set up today.
What the common cards are telling you
| Analysis card | What it establishes | What it does not establish |
|---|---|---|
| Gearing | Cassette range calculated from published smallest and largest sprockets | Lowest complete gear, shift spacing, drivetrain wear, or how the bike feels on a climb |
| Wheel standard | Nominal wheel label and, where supported, ISO bead-seat diameter | Tire width, rim width, clearance, axle standard, or tire compatibility by itself |
| Frame inspection | Material family and the damage patterns that deserve attention | Present condition, crash history, or internal structural integrity |
| Suspension setup | Whether front and/or rear suspension is documented in the archived record | Service condition, correct setup, remaining travel, or proof that every original component is still fitted |
| Brake service | Broad brake-system type and the relevant area of service | Pad or rotor life, fluid condition, cable condition, or a universal wear limit |
| Bottom bracket | A documented interface or the need to verify more dimensions | The exact replacement assembly unless the shell and crank standards are fully identified |
| Tire setup | Published tubeless capability or a documented tire arrangement | Whether tubes are installed, whether sealant is fresh, or whether the current tire and rim combination is approved |
| Published weight | The archived figure supplied for the model | The weight of every size or the bicycle now being inspected |
| Original MSRP | Historical launch-price context | Current retail price, depreciation, asking price, or used value |
The cards shown depend on the evidence available for that record. They are not a fixed checklist that appears identically on every bicycle.
How cassette range is calculated
When the smallest and largest cassette sprockets are clear, Velopedia calculates:
largest sprocket ÷ smallest sprocket × 100
An 11–46-tooth cassette therefore has a range of approximately 418% because 46 ÷ 11 = 4.18. This means the largest sprocket has 4.18 times as many teeth as the smallest. It does not mean the complete bicycle has a 418% range in every configuration.
The cassette figure helps compare gearing breadth when component-group names reveal little. It does not account for chainrings, wheel diameter, crank length, steps between sprockets, or whether the installed drivetrain matches the record. Use the specification table when those details matter.
Why 700C and 622 mm appear together
Traditional wheel names are not dependable compatibility measurements by themselves. The 700C label normally corresponds to a 622 mm bead-seat diameter, the diameter where the tire bead sits in the rim. That is why a card can display “700C · 622 mm.”
The mapping narrows the compatibility question; it doesn’t finish it. Tire width, inner rim width, frame and fork clearance, brake position, and manufacturer limits still matter. Inch labels are especially ambiguous because different bead-seat diameters have shared names such as “26 inch” or “28 inch.” When a card says to confirm the ISO diameter, read the tire sidewall and rim marking rather than ordering from the inch name alone.
Mixed-wheel bicycles need another layer of care. A 29-inch front and 27.5-inch rear system uses different bead-seat diameters, so tires, tubes, rims, and complete spare wheels are not interchangeable from end to end even when their widths look similar.
Treat inspection prompts as priorities, not diagnoses
A frame-material card directs attention to relevant failure signs. Aluminum and steel frames deserve careful inspection around welds, loaded junctions, dents, deformation, and corrosion where applicable. Carbon or other composite frames shift the emphasis toward impact areas, crushed clamping zones, broken fibers, delamination clues, and unexplained changes in shape. The card cannot clear a frame for use.
The same distinction applies to brakes and suspension. “Hydraulic disc” tells you to inspect pad and rotor condition, hose integrity, lever feel, leakage, and use of the correct service fluid. Exact wear limits come from the component manufacturer, not the category label. “Front suspension” identifies a fork as an inspection and service item; it says nothing about bushing play, damper function, air pressure, spring rate, or service history.
Use the linked used-bike inspection guide when a card identifies an area that needs physical checking.
A missing card is not a negative finding
Archive records are uneven because historical source material is uneven. If Velopedia cannot confidently identify a wheel standard, tooth-count span, brake family, or suspension arrangement, the safest result is to omit that interpretation. Absence of a card does not prove absence of the component or feature.
Read the underlying table and note any ambiguity. A bare model name may not expose a service standard. A generic “disc brake” entry may not distinguish mechanical from hydraulic operation. A tire label may combine marketing language with dimensions that need verification. Do not fill those gaps by assumption when ordering parts.
Use the analysis to form the next question
The cards work best as a handoff from research to verification:
- Confirm that you have the correct model, year, size, and build.
- Read the analysis for the relationships most likely to affect inspection or compatibility.
- Check the source fields in the specification and geometry tables.
- Compare the archived build with the physical bicycle.
- Use the exact component model and manufacturer documentation before service or parts ordering.
The Velopedia comparison tool is useful when two records have similar names or when you are deciding between model years. Compare the source specifications first, then use the analysis to understand which differences change fit, service, inspection, or parts compatibility.
For price questions, move to the guide to original MSRP and used-market data. Specification analysis can describe a bike’s equipment and original market position, but it cannot value the condition of the bicycle in front of you.
Sources and technical review
Author: Jeff South
Technical review date: August 15, 2026
- Velopedia Bicycle Archive — archived specifications, normalized geometry, and model-level analysis
- Velopedia: 2025 Marin San Quentin 1 — mixed-wheel, cassette-range, suspension, and tubeless-ready examples
- Schwalbe: Bicycle Tire Dimensions — relationship between tire markings, bead-seat diameter, rim width, and tire width
- Shimano: Disc Brake Rotor Adapter User’s Manual — manufacturer-specific brake inspection guidance and service limits