Velopedia Bicycle Archive

1999 GT Aggressor

Original manufacturer specifications including Mountain Mix drivetrain, 26" wheels, geometry for 1 published size.

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What Velopedia knows

Model year
1999
Category
Mountain
Original MSRP
$386.94
Sizes
12.5", 14.5", 16", 18", 20"
Colors
H.O.T. Black, H.O.T. Red
Geometry
Legacy reference · Geometry context
Record coverage
32 preserved details · original MSRP · preserved geometry
Archive ID
84912
Model history 10 other years
Image not available

Manufacturer catalog

Published sizes and colors

5 sizes · 2 colors

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

Published sizes

12.5"14.5"16"18"20"

Published colors

H.O.T. BlackH.O.T. Red

Frameset

Frame ConstructionTIG-welded
Frame Material7000 aluminum, butted
ForkSR Suntour MG80, 2.5" travel
Fork MaterialChromoly/magnesium, triple-clamp crown
Rear ShockN/A

Drivetrain

Component GroupMountain Mix
ShiftersShimano Altus EZ Fire Plus
Front DerailleurShimano AceraX top-swing
Rear DerailleurShimano Alivio
CranksetSR XR27
Bottom BracketShimano cartridge
BB Shell Width68mm English
Rear Cogs7-speed, 14 - 28 teeth
ChainShimano CN-UG50, 1/2 x 3/32"
PedalsGT nylon ATB

Brakes

BrakesProMax linear-pull brakes, Shimano Altus levers

Cockpit & Contact Points

Headset1 1/8" sealed mechanism
HandlebarFlat
Handlebar ExtensionsNot included
StemGT hi-rise
SaddleGT
SeatpostAluminum micro-adjust

Wheels & Tires

HubsFront: aluminum, Q/R, Rear: Shimano 7-speed cassette
RimsWeinmann 519
SpokesStainless steel, 2.0mm straight gauge
Spoke NipplesBrass nipples
Front Tire26 x 2.10" WTB VelociRaptor
Wheel Size26" wheels

Historical reference geometry

Geometry

Legacy reference · 5 measurements

Historical model-level geometry recovered from Velopedia’s original archive database. The source does not identify which listed frame size this reference describes, so fit interpretation is intentionally limited and no size-normalized Archive Context is generated.

MeasurementLegacy reference
Top tube575 mm
Head-tube angle70.5°
Seat-tube angle73.5°
Chainstay / rear center426 mm
Wheelbase1070 mm

Geometry source: Historical archive database — model-level reference geometry. The historical source provides one model-level geometry set and does not identify the corresponding frame size.

Geometry tools

Explore this historical geometry

Model-level historical reference

Period context: At 70.5°, the head angle sits somewhat slacker than typical among mountain geometries represented in Velopedia for this period. Its 73.5° seat angle is somewhat steeper than typical among the same-period mountain references.

Compared with 1159 distinct legacy mountain geometries from model years 1997–2001. Only angular measurements are used because the historical reference frame size is unidentified.
See it in periodOpen an immediate comparison with preserved 1999 mountain geometries. The source frame size remains unidentified.
See its 1999 geometry context

Parts & serviceability

Find replacement parts

3 top part searches
ChainExact archived part
Shimano CN-UG50, 1/2 x 3/32" Exact archived model
Front tireMatching fit standard
26x2.10" WTB VelociRaptor Named tire and published size
Brake padsMatching fit standard
Linear-pull brake pads Published brake type — verify pad mounting style
More qualified parts (2)
Rear derailleurMatching configuration
Shimano Alivio Interpreted as Shimano Alivio · 7-speed · mechanical Named component · published drivetrain speed — verify exact version
ShiftersQualified part search
Shimano Altus EZ Fire Plus Interpreted as Shimano Altus · 7-speed · mechanical Named component · published drivetrain speed — verify exact version

Searches use the archived manufacturer specification, not the components currently installed on a particular bicycle. Confirm the exact model, size and fit before ordering. As an Amazon Associate I earn from qualifying purchases. Velopedia may also earn from qualifying eBay purchases. Commercial relationships do not influence Archive specifications or analysis.

Used-bike inspection

If you’re buying this bike used

Before any test ride: both brakes should stop the bike firmly and release cleanly; both wheels should run true and be securely attached; tires should have no casing damage; and the headset, handlebar, stem, cranks and pedals should have no looseness or play.

Follow the full used-bike inspection order →
  • FrameLook closely for dents and hairline cracks around welds, the head tube and bottom-bracket area. Cosmetic scratches matter less than a change in shape or a crack line.Inspect the frame and fork →
  • BrakesInspect pad condition, cable movement and the rim sidewalls or brake tracks for wear. A concave or heavily worn braking surface can mean the wheel also needs replacement.Inspect the brakes →
  • SuspensionAsk when the fork was last serviced. Check the stanchions for damage, look for oil at the seals and make sure the fork moves smoothly without bushing play.Evaluate the suspension →
  • DrivetrainShift through every gear under light load and measure chain wear. Confirm that the shifter, derailleur, chain and cassette belong to the same 7-speed system.Check drivetrain wear →
  • Wheels & tiresSpin both wheels and watch the rims for side-to-side or vertical movement. Check for dents, cracks, loose or uneven spokes and hub play, then inspect both tire casings for cuts, cracking or exposed threads.Check wheels and tires →
Bike-specific inspection checklist 20 checks based on 6 archived component groups Open checklistClose checklist
0 of 20 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: 1999 GT Aggressor · Mountain bike, front suspension · Published sizes: 12.5", 14.5", 16", 18", 20"

Archived: Frame: TIG-welded · Fork: SR Suntour MG80, 2.5" travel · Chromoly/magnesium, triple-clamp crown

Archived: Fork: SR Suntour MG80, 2.5" travel

Archived: Group: Mountain Mix · Shifters: Shimano Altus EZ Fire Plus · Front derailleur: Shimano AceraX top-swing · Rear derailleur: Shimano Alivio · Crankset: SR XR27 · Bottom bracket: Shimano cartridge · Rear cogs: 7-speed, 14 - 28 teeth · Chain: Shimano CN-UG50, 1/2 x 3/32"

Archived: Brakes: ProMax linear-pull brakes, Shimano Altus levers

Archived: Wheel size: 26" wheels · Rims: Weinmann 519 · Hubs: Front: aluminum, Q/R, Rear: Shimano 7-speed cassette · Front tire: 26 x 2.10" WTB VelociRaptor

Controls and contact points

Archived: Headset: 1 1/8" sealed mechanism · Handlebar: Flat · Stem: GT hi-rise · Seatpost: Aluminum micro-adjust · Saddle: GT · Pedals: GT nylon ATB

Before and during the test ride

Follow the full used-bike inspection order →

Build relationships are limited to the archived manufacturer specifications. Confirm exact fit and standards before ordering parts or performing service.

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Recently checked marketplace data

Market Snapshot

Checked Sep 25, 2026 11:35 pm

Across 17 qualifying used eBay listings, the median current asking price is $340.00 and the middle half of asks falls between $280.00–$500.00. This is active-listing evidence, not a completed-sale appraisal; condition, size, service history and local demand can change the actual price.

Evidence standard Fixed-price and Best Offer item prices only Shipping and tax excluded Active asks, not completed sales

Model-year coverage: 0 of 27 qualifying asking-price listings explicitly state 1999. There are not yet three year-confirmed used listings, so the used summary is labeled as broader model-family context.

Affiliate disclosure: As an eBay Partner, Velopedia may be compensated if you make a purchase through these links.

Qualified asking evidence2727 high-confidence matches
Model-family used asking$340.00Median asking · middle 50% $280.00–$500.00 · 17 listings
Model-family new asking$375.00Median asking · middle 50% $268.75–$452.13 · 10 listings

Price history

Observed used asking prices

8 observations · Sep 2, 2026 – Sep 25, 2026
Observed used asking-price history 8 dated median asking-price observations from Sep 2, 2026 through Sep 25, 2026. Asking prices are not completed sale prices. $200 $300 $400 $500 $600 Sep 2 Sep 19 Sep 25 Sep 2, 2026: median $340.00 from 19 close used listings Sep 9, 2026: median $340.00 from 21 close used listings Sep 16, 2026: median $332.50 from 20 close used listings Sep 19, 2026: median $345.00 from 18 close used listings Sep 21, 2026: median $345.00 from 18 close used listings Sep 22, 2026: median $345.00 from 18 close used listings Sep 24, 2026: median $350.00 from 19 close used listings Sep 25, 2026: median $340.00 from 17 close used listings

Each dot is a dated Velopedia observation built from at least three high-confidence, fixed-price or Best Offer used-bicycle listings in one consistent identity, methodology, currency and model scope. The shaded band shows the middle 50% when at least five listings supported that observation. Prices exclude shipping and tax; auctions, completed sales and appraisals are not included.

View observation data
ObservedMedianMiddle 50%Matches
Sep 25, 2026$340.00$280.00–$500.0017
Sep 24, 2026$350.00$277.50–$500.0019
Sep 22, 2026$345.00$284.75–$487.5018
Sep 21, 2026$345.00$284.75–$500.0018
Sep 19, 2026$345.00$284.75–$487.5018
Sep 16, 2026$332.50$278.75–$500.0020
Sep 9, 2026$340.00$280.00–$500.0021
Sep 2, 2026$340.00$280.00–$475.0019

See all current matches for this bicycle →

Listings shown have not passed their eBay-supplied end time. Velopedia rechecks matched bicycles on a protected weekly cycle; availability can still change between checks. Price calculations use active fixed-price and Best Offer item prices before shipping and tax. Auction bids, auction-only prices, classified ads, lower-confidence Review candidates and ended listings are excluded. These observations are not completed-sale prices, a certified appraisal or a guarantee of value.

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

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