Bicycle Archive · Specification report

2004 GT Mach 1 Expert

Velopedia Archive ID 31456

Overview

Model year	2004
Brand	GT
Model	Mach 1 Expert
Bicycle type	BMX
Archive ID	31456
Original MSRP	$159.99
Colors	Red, Yellow
Sizes	One

Frameset

Frame construction	TIG-welded
Frame material	Hi-tensile steel
Fork	GT
Fork material	Hi-tensile steel, unicrown crown
Rear shock	N/A

Drivetrain

Component group	N/A
Shifters	N/A
Front derailleur	N/A
Rear derailleur	N/A
Crankset	Steel one-piece, 36 teeth
Bottom bracket	Steel
BB shell width	American
Rear cogs	1-speed, 16 teeth
Chain	KMC Z410, 1/2 x 1/8"
Pedals	GT Johnson design

Brakes

Brakes	Tektro 907A U-brake rear brakes, Tektro 289A rear levers

Cockpit & contact points

Headset	1" steel, threaded
Handlebar	GT BMX
Handlebar extensions	N/A
Stem	Aluminum
Saddle	GT BMX
Seatpost	Chromoly, 22.2mm (7/8 inch) diameter

Wheels & tires

Hubs	Front: steel, nutted, Rear: Shimano Coaster Brake
Rims	Aluminum, 36-hole
Spokes	Steel, 14ga. (2.0mm) straight gauge
Spoke nipples	Brass nipples
Front tire	20 x 1.75" GT Brody Knobs
Wheel size	20" wheels

Geometry · Legacy reference

Top tube	457.2 mm
Head-tube angle	73°
Seat-tube angle	71°
Chainstay / rear center	355.6 mm

Manufacturer-published archive data. Confirm exact standards and dimensions before ordering parts or performing service. Generated by Velopedia on September 27, 2026.