Bicycle Archive · Specification report

2003 GT Thumper

Velopedia Archive ID 38608

Overview

Model year	2003
Brand	GT
Model	Thumper
Bicycle type	Freestyle/jumping
Archive ID	38608
Original MSRP	$299.99
Colors	Moro Blue, TT Gray
Sizes	One

Frameset

Frame construction	TIG-welded
Frame material	Chromoly
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 FX-11 U-brake rear brakes, Tektro 273A rear levers

Cockpit & contact points

Headset	1 1/8" threadless Tange-Seiki TGMX
Handlebar	GT BMX
Handlebar extensions	N/A
Stem	GT Piston
Saddle	GT Launch Pad
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	20 x 2.10" GT LP-4
Wheel size	20" wheels

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