Bicycle Archive · Specification report

Bicycle comparison

1999 GT Bump · 2003 GT Bump

Specification	1999 GT Bump	2003 GT Bump
Overview
Model year	1999	2003
Brand	GT	GT
Model	Bump	Bump
Bicycle type	Freestyle/jumping	Freestyle/jumping
Archive ID	86541	38607
Original MSRP	$316.99	$249.99
Colors	Atomic Blue, Khaki	Blue, Yellow
Sizes	—	One
Frameset
Frame construction	Welded	TIG-welded
Frame material	Chromoly	Chromoly main triangle/hi-tensile steel rear stays
Fork	GT	GT
Fork material	Chromoly, oversize, unicrown crown	Chromoly, unicrown crown
Rear shock	N/A	N/A
Drivetrain
Component group	N/A	N/A
Shifters	N/A	N/A
Front derailleur	N/A	N/A
Rear derailleur	N/A	N/A
Crankset	GT 1-piece chromoly, 44 teeth	GT 3-piece chromoly, 39 teeth
Bottom bracket	One piece	—
BB shell width	—	American
Rear cogs	1-speed, 16 teeth	1-speed, 14 teeth
Chain	1/2 x 1/8"	KMC 410, 1/2 x 3/16"
Pedals	GT aluminum platform	GT Johnson design
Brakes
Brakes	Dia-Compe 990 rear brakes, Dia-Compe MX-97 rear levers	Tektro 907A U-brake rear brakes, Tektro 274A rear levers
Cockpit & contact points
Headset	1 1/8" threadless Aheadset SX-1	1 1/8" threadless Victor VP-A74F
Handlebar	GT	GT BMX
Handlebar extensions	N/A	N/A
Stem	GT Piston	GT Piston
Saddle	GT	GT Jr Jump, 9mm rails
Seatpost	GT chromoly micro-adjust, 31.8mm diameter	Steel micro-adjust
Wheels & tires
Hubs	GT Mohawk	Aluminum, 14mm axle
Rims	Weinmann ZAC-X, 48-hole	Alex G22, 36-hole
Spokes	Steel, 2.0mm straight gauge	Stainless steel, 14ga. (2.0mm) straight gauge
Spoke nipples	Brass nipples	Brass nipples
Front tire	20 x 2.125" Powerlite Retro-Tread	20 x 2.10" GT LP-4
Rear tire	20 x 1.75" Powerlite Retro-Tread	—
Wheel size	20" wheels	20" wheels

Manufacturer-published archive data. Confirm exact standards and dimensions before ordering parts or performing service. Generated by Velopedia on November 13, 2026.