Velopedia Bicycle Archive

1993 Diamondback Topanga

Original specifications: Shimano Altus A20 Rapidfire Plus drivetrain · 26" wheels · legacy reference geometry.

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At a glance

Model year
1993
Category
Mountain
Original MSRP
$400.00
Sizes
14, 16, 18, 20. Womens: 16, 20.
Geometry
Legacy reference
In this record
20 specifications · original MSRP · geometry
Archive ID
40517
Model history 8 other years
Original buildChrome-moly OS main tubes · Shimano Altus A20 Rapidfire Plus · 26" wheels

Manufacturer catalog

Published sizes and colors

5 sizes

Manufacturer-published sizes and colors; availability and exact size/color pairings may vary by market or production run.

Published sizes

14161820. Womens: 1620.

Frameset

Frame ConstructionTIG-welded steel
Frame MaterialChrome-moly OS main tubes
ForkDiamond Back chrome-moly

Drivetrain

Component GroupShimano Altus A20 Rapidfire Plus
ShiftersShimano Altus A20 Rapidfire Plus
Front DerailleurShimano Altus C10
Rear DerailleurShimano Altus A20
CranksetShimano Altus A20, 28/38/48 teeth
Rear Cogs7-speed, 12 - 28 teeth
ChainShimano CN-UG50
PedalsVictor Zytel MTB w/cromo axle

Brakes

BrakesShimano Altus C10 brakes, levers

Cockpit & Contact Points

HandlebarDiamond Back
StemDiamond Back MTB TIG
SaddleAvenir Gel Comp
SeatpostAlloy 300mm w/QR

Wheels & Tires

HubsShimano alloy
RimsSun Metal L18, 36-hole
Front Tire26 x 1.95" Avenir Vigor
Wheel Size26" wheels

Geometry

Legacy reference · 6 measurements

Model-level measurements; the frame size was not recorded. Use these as a historical reference, not for size-specific fit.

All geometry measurementsLegacy reference · 6 measurements
MeasurementLegacy reference
Top tube579.1 mm
Head-tube angle71°
Seat-tube angle71°
Chainstay / rear center424.2 mm
Wheelbase1077 mm
Fork offset / rake45.7 mm

The preserved source contains one model-level geometry set without an identified frame size.

Gearing

Chainring ÷ rear sprocket

Lower ratios provide more mechanical advantage for climbing. Higher ratios turn the rear wheel farther with each crank revolution.

Published build48/38/28T · 12–28T · 7-speed
Lowest1.00:1 Highest4.00:1 Total range400%
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Parts & serviceability

Find replacement parts

Original specifications
Chain · Original
Shimano CN-UG50
Crankset · Original
Shimano Altus A20, 28/38/48 teeth
Front derailleur · Original
Shimano Altus C10 Search: Shimano Altus 7-speed mechanical front derailleur
More parts (2)
Rear derailleur · Original
Shimano Altus A20 Search: Shimano Altus 7-speed mechanical rear derailleur
Shifters · Original
Shimano Altus A20 Rapidfire Plus Search: Shimano Altus 7-speed mechanical shifter

Based on the original build. Confirm the model, size and fit before ordering; installed parts may differ. As an Amazon Associate I earn from qualifying purchases. Velopedia may also earn from qualifying eBay purchases.

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Bike-specific inspection checklist 19 checks based on 5 archived component groups Open checklistClose checklist
0 of 19 checked Progress stays in this browser for this bike.

This checklist uses the archived equipment for this bike. It cannot confirm the condition, service history or later component changes of the example in front of you.

Archived: 1993 Diamondback Topanga · Mountain bike, non-suspension · Published sizes: 14, 16, 18, 20. Womens: 16, 20.

Archived: Frame: TIG-welded steel · Fork: Diamond Back chrome-moly

Archived: Group: Shimano Altus A20 Rapidfire Plus · Shifters: Shimano Altus A20 Rapidfire Plus · Front derailleur: Shimano Altus C10 · Rear derailleur: Shimano Altus A20 · Crankset: Shimano Altus A20, 28/38/48 teeth · Rear cogs: 7-speed, 12 - 28 teeth · Chain: Shimano CN-UG50

Archived: Brakes: Shimano Altus C10 brakes, levers

Archived: Wheel size: 26" wheels · Rims: Sun Metal L18, 36-hole · Hubs: Shimano alloy · Front tire: 26 x 1.95" Avenir Vigor

Controls and contact points

Archived: Handlebar: Diamond Back · Stem: Diamond Back MTB TIG · Seatpost: Alloy 300mm w/QR · Saddle: Avenir Gel Comp · Pedals: Victor Zytel MTB w/cromo axle

Before and during the test ride

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Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.

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