Specialized Hotrock 24 21-Speed Boys

2012 YouthGeneral youth Manufacturer page

Fork travel: 50 mm
Wheels: 24″
Drivetrain: 3 × 7 24–42t / 14–28t
Gear range: 350%
Frame: Aluminum
Brakes: Rim brake

Sizes

Size guide

7-SPD
21"

The manufacturer did not publish rider heights for these sizes.

Components

11 of 23 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

Specialized A1 Premium Aluminum, 24"" frame, suspension fork geo w/ low standover TT, formed DT/TT, forged dropouts w/ replaceable hanger Not identified

Suspension

1 part

Fork
- SR Suntour
JR-24

Drivetrain

7 parts

Bottom bracket

Water sealed, loose ball, 68mm x 128mm Not identified
Cassette
- Shimano 14–28t
Chain
- KMC
Crankset

Forged alloy arms, triple chainring with chainguard Not identified
Front derailleur
- Shimano
FD-CO50
Rear derailleur
- Shimano RD-TX31
RD-TX31TX-31
Shifters
- Shimano
RS-31

Brakes

2 parts

Brake levers
- Tektro Junior
Brakes

Front: Die cast, alloy ""V"" brake, 1pc. pad, Rear: Die cast, alloy ""V"" brake, 1pc. pad Not identified

Wheels and tires

5 parts

Front hub

Forged alloy, loose ball, nutted axle, 32h Not identified
Rear hub

Forged alloy, freewheel type, 32h, nutted axle Not identified
Rims
- Alex Rims
C-1000
Spokes

Stainless, 2.0mm (14g) Not identified
Tires
- Specialized

Cockpit and contact points

7 parts

Grips
- Specialized
Handlebar

Hi-Ten riserbar, 40mm rise, 10º backsweep, 6º upsweep, 25.4mm Not identified
Headset

1-1/8"" threadless, loose ball Not identified
Pedals

Composite platform w/ reflectors, loose ball, 9/16"" Not identified
Saddle
- Specialized
Seatpost

Alloy, 27.2mm, micro adjust Not identified
Stem

Alloy Ahead, 4 bolt, 20º rise, 25.4mm clamp Not identified

Sizes and geometry

2 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 7-SPD

Table

Geometry diagram unavailable

The drawing needs reach and stack, which the manufacturer did not publish. Available facts remain in the table.

Size

Complete manufacturer geometry table 2 published sizes

Complete manufacturer geometry by size
Measurement
Top tube lengthmm	507	507
Seat tube lengthmm	312	312
Head tube lengthmm	120	120
Head tube angle	69°	69°
Seat tube angle	73°	73°
Chainstay lengthmm	410	420
Wheelbasemm	978	992
Front centermm	572	572
Bottom bracket heightmm	262	262
Standover heightmm	586	586
Fork rakemm	40	40

Not published by the manufacturer: Reach, Stack, Bottom bracket drop, Trail, Stack/reach ratio, Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: boys
Frame material: Aluminum
Fork material: Aluminum

Suspension

Suspension configuration: Hardtail
Front travel: 50 mm

Drivetrain

Derived by Bikelake

Front chainrings: 3
Smallest chainring: 24
Largest chainring: 42
Rear sprockets: 7
Smallest sprocket: 14
Largest sprocket: 28
Lowest gear: 20.6 in
Highest gear: 72.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Rim brake

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Fork spring: Coil
Tire width: 2.125″
Wheel material: Aluminum
Wheel size: 24″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.9 km/h
Highest gear: 27.6 km/h

Total gear range 350%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 20.6–72.0 gear inches

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2012 builds

Differences across 2012 builds
Specification	This bicycle Specialized Hotrock 24 21-Speed Boys	Specialized Hotrock 12 Coaster Boys	Specialized Hotrock 12 Coaster Girls	Specialized Hotrock 16 Coaster Boys	Specialized Hotrock 16 Coaster Girls	Specialized Hotrock 20 Boys 6-speed
Frame
Intended fit	boys	boys	girls	boys	girls	boys
Suspension
Suspension configuration	Hardtail	Rigid	Rigid	Rigid	Rigid	Hardtail
Front travel	50 mm	Not informed	Not informed	Not informed	Not informed	40 mm
Drivetrain
Front chainrings	3	1	1	1	1	1
Smallest chainring	24	28	28	28	28	36
Largest chainring	42	28	28	28	28	36
Rear sprockets	7	Not informed	Not informed	Not informed	Not informed	6
Smallest sprocket	14	Not informed	Not informed	Not informed	Not informed	14
Largest sprocket	28	Not informed	Not informed	Not informed	Not informed	28
Lowest gear	20.6 in	Not informed	Not informed	Not informed	Not informed	25.7 in
Highest gear	72.0 in	Not informed	Not informed	Not informed	Not informed	51.4 in
Brakes
Brake type	Rim brake	Coaster brake	Coaster brake	Coaster brake	Coaster brake	Rim brake
Other specifications
Fork spring	Coil	Not informed	Not informed	Not informed	Not informed	Coil
Suspension	Hardtail	Rigid	Rigid	Rigid	Rigid	Hardtail
Tire width	2.125″	2″	2″	2″	2″	2.125″
Wheel size	24″	12″	12″	16″	16″	20″