Transition Spire Alloy GX

Name: Transition Spire Alloy GX
Brand: Transition

2025 MountainEnduro Manufacturer page

Last known price: $4,999

Prices shown first for United States
Travel: 170 / 170 mm Fork / rear shock
Wheels: 29″
Drivetrain: 1 × 12 30t / 10–52t
Gear range: 520%
Weight: 16.33 kg 36.0 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM High 154–170
SM Low 154–170
MD High 164–182
MD Low 164–182
LG High 175–190
LG Low 175–190
XL High 184–200
XL Low 184–200
XXL High 190–207
XXL Low 190–207

Components

19 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

Spire Alloy 170mm Not identified

Suspension

2 parts

Drivetrain

7 parts

Bottom bracket

73mm BSA Threaded Not identified
Cassette
- SRAM XG-1275 Eagle 12 speeds 10–52t
XG-1275
Chain
- SRAM GX Eagle 12 speeds
Chain guide
- OneUp
Crankset
- SRAM GX Eagle DUB 11 speeds 30t
Rear derailleur
- SRAM GX Eagle 12 speeds
Shifters
- SRAM GX Eagle Trigger 12 speeds

Brakes

2 parts

Brakes
- TRP DH-R EVO
Disc rotors
- TRP

Wheels and tires

5 parts

Cockpit and contact points

6 parts

Grips
- ODI
Handlebar

ANVL Mandrel Alloy 35, SM (800x20mm), MD/LG/XL (800x30mm), XXL(800x40mm) Not identified
Headset
- FSA
Saddle
- SDG Bel-Air
Seatpost
- OneUp
Stem

ANVL Swage (40mm) Not identified

Sizes and geometry

10 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size LG High

Table

Reach 485mm

Stack 628mm

Wheelbase 1287mm

Head angle 63.0°

Seat angle 78.1°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 29″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 10 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	430	425	460	455	485	480	510	505	535	530
Stackmm	619	624	619	624	628	633	637	642	646	651
Top tube lengthmm	547	550	577	580	605	608	633	636	661	664
Seat tube lengthmm	360	360	390	390	430	430	460	460	490	490
Head tube lengthmm	100	100	100	100	110	110	120	120	130	130
Head tube angle	63°	62.5°	63°	62.5°	63°	62.5°	63°	62.5°	63°	62.5°
Seat tube angle	79.6°	79.1°	78.8°	78.3°	78.1°	77.6°	77.5°	77°	77.2°	76.7°
Chainstay lengthmm	446	448	446	448	446	448	452	454	452	454
Wheelbasemm	1227	1229	1257	1259	1287	1289	1322	1324	1352	1354
Front centermm	782	783	812	813	842	843	871	872	901	902
Bottom bracket dropmm	25	32	25	32	25	32	25	32	25	32
Bottom bracket heightmm	350	343	350	343	350	343	350	343	350	343
Standover heightmm	685	680	700	695	715	710	730	725	745	740
Fork rakemm	44	44	44	44	44	44	44	44	44	44
Trailmm	141	146	141	146	141	145	141	146	141	146
Stack/reach ratio	1.44	1.47	1.35	1.37	1.30	1.32	1.25	1.27	1.21	1.23

Not published by the manufacturer: Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Bicycle weight: 16.33 kg

36.0 lb

Suspension

Suspension configuration: Full suspension
Front travel: 170 mm
Rear travel: 170 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 30
Largest chainring: 30
Rear sprockets: 12
Smallest sprocket: 10
Largest sprocket: 52
Lowest gear: 16.7 in
Highest gear: 87.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Derailleur hanger: UDH
Seatpost: Dropper seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: BSA
Fork spring: Air
Tire clearance: Maximum tire width: 2.6″
Tire width: 2.4″
Wheel material: Aluminum
Wheel size: 29″

Technical analysis

3 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Front travel

170 mm

This value is within the central range for this class.

Cohort: Mountain / Enduro Model year: 2025
Sample: 1,418 bicycles with this information
Coverage: 97.5% of the class

Rear travel

170 mm

This value is above the central range for this class.

Cohort: Mountain / Enduro Model year: 2025
Sample: 1,105 bicycles with this information
Coverage: 75.9% of the class

Shifting

Mechanical

476 of 1,454 bicycles with this information use electronic shifting.

Cohort: Mountain / Enduro Model year: 2025
Sample: 1,454 bicycles with this information
Coverage: 100.0% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.4 km/h
Highest gear: 33.3 km/h

Total gear range 520%

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: 16.7–87.0 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 2025 builds
Specification	This bicycle Transition Spire Alloy GX	Transition Spire Alloy NX	Transition Spire Carbon GX	Transition Spire Carbon XO AXS
Frame
Frame material	Aluminum	Aluminum	Carbon	Carbon
Bicycle weight	16.33 kg	16.65 kg	15.29 kg	14.92 kg
Drivetrain
Smallest sprocket	10	11	10	10
Largest sprocket	52	50	52	52
Lowest gear	16.7 in	17.4 in	16.7 in	16.7 in
Highest gear	87.0 in	79.1 in	87.0 in	87.0 in
Cockpit
Shifting	Mechanical	Mechanical	Mechanical	Electronic