Stumpjumper 15 Alloy
OverviewAbout the Specialized Stumpjumper 15 Alloy
The Specialized Stumpjumper 15 Alloy is a mountain bike, built on a aluminium frame, listed at $4,000. An off-road bike for trails, with grippy tyres and trail-ready geometry.
SizingWhat size Stumpjumper 15 Alloy do I need?
Enter your height to see the size Specialized recommends.
| Size | Rider height | In feet |
|---|---|---|
| S1 | 150 to 160 cm | 4 ft 11 in to 5 ft 3 in |
| S2 | 157 to 173 cm | 5 ft 2 in to 5 ft 8 in |
| S3 | 165 to 180 cm | 5 ft 5 in to 5 ft 11 in |
| S4 | 173 to 188 cm | 5 ft 8 in to 6 ft 2 in |
| S5 | 178 to 193 cm | 5 ft 10 in to 6 ft 4 in |
| S6 | 188 to 203 cm | 6 ft 2 in to 6 ft 8 in |
Rider heights from Specialized's size chart. Height is a starting point: arm and leg length, flexibility and riding style all matter, so a test ride beats any chart. How bike sizing works.
SpecificationsWhat we know
- Brand
- Specialized
- Model year
- 2025
- Category
- Mountain
- Frame
- Aluminium
- Wheel size
- 29-inch
- Drivetrain
- Shimano Deore M6100 1x12
- Brakes
- Disc
- Frame sizes
- S1, S2, S3, S4, S5, S6
- Price
- $4,000, RRP AUD (Specialized Australia, checked 14 Oct 2026)
Specs and pricing are listed in AUD and sourced from Australian retail listings. Confirm the current details and availability with the seller before purchase.
GeometrySize S4
- Stack
- 640 mm
- Reach
- 475 mm
- Stack/reach
- 1.35
- Head angle
- 64.5 deg
- Seat angle
- 76.5 deg
- Wheelbase
- 1244 mm
- Chainstay
- 435 mm
- BB drop
- 38 mm
- Standover
- 745 mm
- Fork rake
- 44 mm
GearingRatios
Ratios are derived from the chainrings and cassette. They describe the gearing, not any rider's ability.
Drivetrain & buildFull specification
- Groupset
- Shimano Deore M6100 12-speed
- Shifting
- Mechanical
- Drive
- 1x
- Speeds
- 12
- Crank
- Shimano Deore M6120, 30T, 170mm (S4)
- Chainrings
- 30
- Cassette
- Shimano Deore M6100 12-speed Hyperglide+
- Rear derailleur
- Shimano Deore M6100 Shadow Plus
- Brakes
- Shimano BR-MT420 4-piston hydraulic disc
- Rotors
- 203/203mm (S3-S6)
- Wheelset
- Specialized alloy, tubeless ready, 28h, 15x110 front / 12x148 rear thru-axle hubs
- Rim internal width
- 29 mm
- Stock tyre
- 29x2.3
- Tubeless
- Yes
- Fork material
- Alloy (RockShox Psylo Silver)
- BB standard
- Threaded
- Thru-axle
- 15x110 front, 12x148 rear
- Seatpost
- TranzX dropper, 200mm (S4), 34.9mm
- Cockpit
- Specialized 6000 series alloy bar 800mm wide, 30mm rise (S3-S4), alloy trail stem 35mm bore
- Saddle
- Bridge, steel rails, 143mm
- Mounts
- SWAT downtube storage door
- UDH
- Yes
SuspensionMTB detail
- Front travel
- 150 mm
- Rear travel
- 145 mm
- Fork
- RockShox Psylo Silver, Motion Control Damper, 44mm offset
- Shock
- X-Fusion 02 Pro RL, Ride Dynamics Trail Tune, 210x55mm
- Wheel config
- 29
- Dropper
- TranzX Dropper, remote SLR LE lever
- Dropper travel
- 200 mm
- Discipline
- Trail
- Suspension
- Specialized FSR-style rear link, 145mm travel (Stumpjumper 15 kinematics)
Bike DNAWhat the numbers say
- Steering
- A 64.5 deg head angle points to very slack, built for steep descending.
- Climbing
- Lowest ratio 0.59 is a very low climbing gear for steep or loaded climbs.
Derived from the published geometry and gearing above. It describes the numbers, not a ride test.
BikeFinder Data Profile: geometry and specification researched from published sources (Specialized AU product page (spec, geometry S4, weight, price, size guide)), verified 2026-10-14. This is a specification analysis, not a physical ride review.
Where to buyStockist
BikeFinder is an independent directory. We link to retailers; prices and stock are set by the seller and shown as at the date checked.
