Bicycle comparison

2004 GT Bump · 2006 GT Bump

Specification	2004 GT Bump	2006 GT Bump
Overview
Model year	2004	2006
Brand	GT	GT
Model	Bump	Bump
Bicycle type	Freestyle/jumping	BMX
Archive ID	31429	11306
Original MSRP	$249.99	$269.99
Colors	Red, Silver	RootBeer Brown, Pink
Sizes	One	20" wheel
Frameset
Frame construction	TIG-welded	TIG-welded
Frame material	Chromoly main triangle/hi-tensile steel rear stays	3-tube chromoly
Fork	GT	'05 GT dirt jump design
Fork material	Chromoly, unicrown crown	Chromoly
Rear shock	N/A	N/A
Drivetrain
Component group	N/A	BMX
Shifters	N/A	N/A
Front derailleur	N/A	N/A
Rear derailleur	N/A	N/A
Crankset	GT 3-piece chromoly, 39 teeth	GT Tubular Cr-Mo 3pc, 36 teeth
Bottom bracket	—	Steel, ball type
BB shell width	American	—
Rear cogs	1-speed, 14 teeth	1-speed, 13 teeth
Chain	KMC 410, 1/2 x 3/16"	KMC Z410
Pedals	GT Johnson design	'05 GT Dirt/Street platform design, aluminum body, cr-mo alxe
Brakes
Brakes	Tektro 907A U-brake rear brakes, Tektro 274A rear levers	Alloy side-pull caliper front/Tektro, 907AD, dual anchor bolts, forged aluminum U-brake rear brakes, Tektro, 274A, aluminum levers
Cockpit & contact points
Headset	1 1/8" threadless Victor VP-A74F	1 1/8" Tange Seiki FATTY 22, extra deep cup engagement
Handlebar	GT BMX	GT dirt/street bend, Cr-mo, 7" rise
Handlebar extensions	N/A	N/A
Stem	GT Piston	GT Johnson III design, cold forged aluminum
Saddle	GT Jr Jump, 9mm rails	GT "Star 19" two piece design, 9mm rails
Seatpost	Steel micro-adjust	Aluminum double bolt micro adjust
Wheels & tires
Hubs	Aluminum, 14mm axle	Front: '05 GT branded, aluminum body, sealed Mech. bearings, 3/8" Cr-Mo axle, 36 h, Rear: '05 GT branded, aluminum body, sealed Mech. bearins, 14mm Cr-Mo axle, 36 ho
Rims	Alex G22, 36-hole	Alex G22, aluminum, 36 hole, 30mm width, 36-hole
Spokes	Stainless steel, 14ga. (2.0mm) straight gauge	14ga. (2.0mm) Straight Gauge
Spoke nipples	Brass nipples	Brass nipples
Front tire	20 x 2.20" GT 1453	26 x 2.20" GT-1453
Rear tire	20 x 2.10" GT LP-4	26 X 2.10" GT LP-IV
Wheel size	20" wheels	26" wheels

Specification

2004 GT Bump

2006 GT Bump

Overview

Model year

2004

2006

Brand

Model

Bump

Bicycle type

Freestyle/jumping

BMX

Archive ID

31429

11306

Original MSRP

$249.99

$269.99

Colors

Red, Silver

RootBeer Brown, Pink

Sizes

One

20" wheel

Frameset

Frame construction

TIG-welded

Frame material

Chromoly main triangle/hi-tensile steel rear stays

3-tube chromoly

Fork

'05 GT dirt jump design

Fork material

Chromoly, unicrown crown

Chromoly

Rear shock

N/A

Drivetrain

Component group

N/A

BMX

Shifters

N/A

Front derailleur

N/A

Rear derailleur

N/A

Crankset

GT 3-piece chromoly, 39 teeth

GT Tubular Cr-Mo 3pc, 36 teeth

Bottom bracket

—

Steel, ball type

BB shell width

American

—

Rear cogs

1-speed, 14 teeth

1-speed, 13 teeth

Chain

KMC 410, 1/2 x 3/16"

KMC Z410

Pedals

GT Johnson design

'05 GT Dirt/Street platform design, aluminum body, cr-mo alxe

Brakes

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

Alloy side-pull caliper front/Tektro, 907AD, dual anchor bolts, forged aluminum U-brake rear brakes, Tektro, 274A, aluminum levers

Cockpit & contact points

Headset

1 1/8" threadless Victor VP-A74F

1 1/8" Tange Seiki FATTY 22, extra deep cup engagement

Handlebar

GT BMX

GT dirt/street bend, Cr-mo, 7" rise

Handlebar extensions

N/A

Stem

GT Piston

GT Johnson III design, cold forged aluminum

Saddle

GT Jr Jump, 9mm rails

GT "Star 19" two piece design, 9mm rails

Seatpost

Steel micro-adjust

Aluminum double bolt micro adjust

Wheels & tires

Hubs

Aluminum, 14mm axle

Front: '05 GT branded, aluminum body, sealed Mech. bearings, 3/8" Cr-Mo axle, 36 h, Rear: '05 GT branded, aluminum body, sealed Mech. bearins, 14mm Cr-Mo axle, 36 ho

Rims

Alex G22, 36-hole

Alex G22, aluminum, 36 hole, 30mm width, 36-hole

Spokes

Stainless steel, 14ga. (2.0mm) straight gauge

14ga. (2.0mm) Straight Gauge

Spoke nipples

Brass nipples

Front tire

20 x 2.20" GT 1453

26 x 2.20" GT-1453

Rear tire

20 x 2.10" GT LP-4

26 X 2.10" GT LP-IV

Wheel size

20" wheels

26" wheels

Geometry comparison

One selected size or frame position per bicycle, matching the comparison dropdown choices used when Print / PDF was opened.

Measurement	2004 GT Bump	2006 GT Bump
Selected size / position	Legacy reference	—
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 November 13, 2026.