Velopedia Bicycle Archive

Compare Bicycles

Compare published geometry, gearing and specifications for up to three bicycles.

1 of 2 bicycles

At a glance

Key differences

Supported differences are shown below. Data limitations are labeled separately.

  1. Data limitation

    No geometry is recorded for 2012 GT Bump and 2011 GT Bump.

Gearing comparison

Lower gears help on climbs. Higher gears suit higher speeds.

RPM

RPM = pedal turns per minute.

2012 GT Bump25T · 9T
Ratio2.78:1

Speed unavailable: wheel or tire size is missing or unclear.

2011 GT Bump25T · 9T
Ratio2.78:1
Estimated speed at 90 RPMGear15.0 mph

Rear tire: 20×2.1.

How it works

Ratio = front teeth ÷ rear teeth. Hub gears also include the hub’s internal ratio. A 400% range means the highest ratio is four times the lowest.

Speeds are estimates from tire size and pedal cadence. Actual speeds vary.

Try other gearing

Complete specification tableShows different published values and gaps where a bicycle lacks data. Different wording reflects source language, not necessarily different components. Swipe for more columns.
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Specification
2012 GT Bump
2011 GT Bump
Overview
Model Year
2012
2011
Brand
GT
GT
Model
Bump
Bump
Bicycle Type
BMX
BMX
Colors
Satin Black, Satin White
White, Matte Green
Sizes
One Size
—
Weight
—
—
Frameset
Frame Construction
—
Steel
Frame Material
Straight Guage Cro-Mo
CroMo
Fork
GT Cro-Mo
Cromo
Fork Material
—
Steel
Drivetrain
Component Group
—
BMX Mix
Crankset
GT 3-pc Cro-Mo 175mm 25t
CroMO 3 piece, 25t teeth
Bottom Bracket
Sealed Mid
Sealed Bearing
Cassette
KT Cro-Mo 9t
Cassette cog
Rear Cogs
—
9 teeth
Chain
KMC Z510
KMC Z510
Pedals
GT Pro Plastic
GT Dirt/Street platform
Brakes
Brakes
Tektro FX340R
—
Cockpit & Contact Points
Headset
FDP Integrated
1 1/8" integrated
Handlebar
GT Freestyle
GT Pro Steel
Handlebar Extensions
—
Not included
Stem
GT Freestyle
GT freestyle drop
Saddle
GT Dirt Unified
Pivotal Street Design
Seatpost
GT Unified
Pivotal, 25.4mm diameter
Wheels & Tires
Hubs
GT Alloy Sealed 32h GT Alloy Sealed Cassette 36h
Front: GT Aluminum, Rear: GT Alloy
Rims
—
Alienation PBR, 32-hole/36-hole
Spokes
—
14ga. (2.0mm)
Spoke Nipples
—
Brass
Front Tire
GT Dirt 2.125
20 x 2.125" Kenda K-Rad
Rear Tire
—
20 x 2.1" Kenda Ko-Rolla
Wheel Size
—
20" wheels

Historical specifications are presented as an archival reference. Components may have varied by market, size, or production run.

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