Bicycle Archive · Specification report

2004 GT Bump

Velopedia Archive ID 31429

Overview

Model year	2004
Brand	GT
Model	Bump
Bicycle type	Freestyle/jumping
Archive ID	31429
Original MSRP	$249.99
Colors	Red, Silver
Sizes	One

Frameset

Frame construction	TIG-welded
Frame material	Chromoly main triangle/hi-tensile steel rear stays
Fork	GT
Fork material	Chromoly, unicrown crown
Rear shock	N/A

Drivetrain

Component group	N/A
Shifters	N/A
Front derailleur	N/A
Rear derailleur	N/A
Crankset	GT 3-piece chromoly, 39 teeth
BB shell width	American
Rear cogs	1-speed, 14 teeth
Chain	KMC 410, 1/2 x 3/16"
Pedals	GT Johnson design

Brakes

Brakes	Tektro 907A U-brake rear brakes, Tektro 274A rear levers

Cockpit & contact points

Headset	1 1/8" threadless Victor VP-A74F
Handlebar	GT BMX
Handlebar extensions	N/A
Stem	GT Piston
Saddle	GT Jr Jump, 9mm rails
Seatpost	Steel micro-adjust

Wheels & tires

Hubs	Aluminum, 14mm axle
Rims	Alex G22, 36-hole
Spokes	Stainless steel, 14ga. (2.0mm) straight gauge
Spoke nipples	Brass nipples
Front tire	Front: 20 x 2.20" GT 1453, Rear: 20 x 2.10" GT LP-4
Wheel size	20" wheels

Geometry · Legacy reference

Top tube	520.7 mm
Head-tube angle	74.5°
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 26, 2026.