Velopedia Bicycle Archive

2006 GT Mach One Pro

Original specifications: BMX drivetrain · 20" wheels.

Share owner experience

At a glance

Archive #11384

Model year: 2006
Category: BMX
Original MSRP: $209.99
Sizes: 20" wheel
Colors: Absolute Purple, Gloss Black
In this record: 23 specifications · archived image · original MSRP

Model history 4 other years

Browse other years

Compare side by side

Identification clues

2006 archived details

Published colors: Absolute Purple, Gloss Black
Frame: GT BMX dirt jump styling, Cr-Mo down tube
Original equipment: BMX

Clues, not proof of model year. Colors vary and components may have been replaced.

Original buildGT BMX dirt jump styling, Cr-Mo down tube · BMX · 20" wheels

Historical catalog variants

Archived sizes and colors

2 item records

Item-level catalog entries recovered from Velopedia’s original bicycle archive. They document how this model was listed historically; they do not identify the frame size associated with legacy reference geometry or indicate current availability.

Published sizes

20" wheel

Published colors

Absolute PurpleGloss Black

View 2 archived size/color combinations

Size	Color
20" wheel	Absolute Purple
20" wheel	Gloss Black

Historical catalog evidence. Exact specifications and naming may vary by market, production run or manufacturer revision.

Frameset

Frame Construction	TIG-welded
Frame Material	GT BMX dirt jump styling, Cr-Mo down tube
Fork	GT BMX design
Fork Material	Steel/cromo

Drivetrain

Component Group	BMX
Crankset	GT forged three-piece type, 42 teeth
Bottom Bracket	Steel, Ball type
Rear Cogs	1-speed, 16 teeth
Chain	KMC Z410
Pedals	GT BMX platform design, aluminum body, fixed pins, cr-mo alxe

Brakes

Brakes	Alloy side-pull caliper front/Tektro alloy V-type rear brakes, Tektro, 319, aluminum levers

Cockpit & Contact Points

Headset	1 1/8" VP-A74F HD steel, extra deep cup engagement
Handlebar	GT BMX design, Hi-Ten, 7" rise
Stem	GT branded, aluminum
Saddle	GT BMX "Pro Lite", padded with stitched cover and 7mm rails
Seatpost	Aluminum, 25.4mm diameter

Wheels & Tires

Hubs	GT Mohawk, aluminum shell
Rims	Jalco ST-32, aluminum, 36 hole, 31mm width, 36-hole
Spokes	14ga. (2.0mm) Straight Gauge
Spoke Nipples	Brass nipples
Front Tire	20 x 2.125" GT Brody Knob
Rear Tire	20 x 1.75" GT Brody Knob
Wheel Size	20" wheels

Gearing

Lower gears help on climbs. Higher gears suit higher speeds.

Pedal cadence

RPM

Speed units

RPM = pedal turns per minute.

Published build42T · 16T · 1-speed

Ratio2.63:1

Estimated speed At 90 RPM Gear13.7 mph

Rear tire: 20×1.75.

How it works

Ratio = front teeth ÷ rear teeth. Hub gears also include the hub’s internal ratio. A 400% range means the highest ratio is four times the lowest.

Speeds are estimates from tire size and pedal cadence. Actual speeds vary.

Try other gearing

Try your current gearingChanged tires or gears? Calculate your setup.

Your changes apply to this calculation. The archived build stays unchanged.

Gears Drivetrain

Front teeth Smallest rear teeth Largest rear teeth

Use up to three front tooth counts, separated by /. For one rear sprocket, enter the same count twice.

Rear tire

Rear tire marking

Apply the marking on your rear tire or edit its dimensions below. Older or fractional inch sizes need the ISO marking (e.g. 37-590).

Rim diameter (BSD, mm) Tire width (mm)

For 32-622, width is 32 mm and rim diameter is 622 mm. Use the rear tire on mixed-wheel bikes. Leave both fields empty to compare ratios only.

Cadence (RPM) Speed units

Gear, dimension and cadence changes update results automatically.

Gearing comparison
Measure	Original	Your setup
Lowest ratio	—	—
Highest ratio	—	—
Total range	—	—
Lowest-gear speed	—	—
Highest-gear speed	—	—

Speeds are estimates. These calculations do not establish component compatibility or available tire clearance.

Parts & serviceability

Find replacement parts

Original specifications

Seatpost · Original

Aluminum

25.4mm diameter

Search Amazon Search eBay

Based on the original build. Check fit and installed parts before ordering. Affiliate links may earn Velopedia a commission. As an Amazon Associate I earn from qualifying purchases.

Parts and service referenceQuick reference before buying parts

Archived specifications for reference. Check the fitted parts before ordering.

Front tire: Front: 20 x 2.125" GT Brody Knob, Rear: 20 x 1.75" GT Brody Knob
Drivetrain: 1-speed
Seatpost diameter: 25.4 mm
Bottom bracket / shell: Steel, Ball type

Have you owned this model?Help document firsthand fit, ride and maintenance details that may no longer be available.

This archive record has limited published detail. Share what would help another rider understand how this model fit, rode and held up over time. Velopedia reviews every contribution before publication.

Display name Required Email address Required · private Ownership Required When or how long you owned it Required Frame size Required Primary type of riding Required Rider height Optional

Overall owner experience Required · at least 120 characters0 of 120 minimum characters Would you own one again? Optional

Add fit, maintenance and buyer detailsOptional · five additional fields

Fit and sizing observations Optional Long-term strengths Optional Problems or recurring maintenance Optional Parts replaced or upgraded Optional What a used buyer should inspect Optional

Your contribution goes directly to Velopedia’s private review queue. We’ll email an optional confirmation link plus a private edit and withdrawal link, but you do not need to confirm your email before an administrator can review or approve the submission.

Already contributed? Send me a fresh private edit link

For privacy, Velopedia shows the same confirmation whether or not an experience exists.

Checking current listings…

Find this bike on eBay

Search eBay US; check the model year, size and installed components. We may earn a commission from purchases.

Search 2006 model Search all years

Campaign

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

2006 GT Mach One Pro