Reign SX
Giant
Downhill
Reign SX is an alloy downhill mountain bike (2025), from Giant, in the Reign series. This model is best for riders who want a more active, performance-leaning off-road feel, with a sporty, active riding position, and is more at home in gravity-focused bike park riding. Based on the metrics, key strengths are capable suspension support for rougher terrain, strong climbing friendliness for sustained uphill riding, and good fit flexibility for dialing in rider position. The trade-off to keep in mind is a firmer ride feel than comfort-first options and less emphasis on outright speed than speed-focused builds. Compare this bike on MatchBikes.com to similar downhill models.
7.1
Rating

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Score Summary
Performance
7.3
Value
5.6
Fit
7.7
Performance
Built for speed and efficiency
Speed
3.6
Very Low
Climbing Efficiency
7.4
Climber
Suspension
9.0
Extreme rough-terrain ready
Fit
Dialed-in Fit & Comfort
Riding Position
7.0
Sporty
Fit Flexibility
7.1
Adjustable
Ride Comfort
8.3
Firm
Value
Value for Money
5.6
Fair Value
Surface Range
Bike ParkSpecifications
General
Brand
Giant
Model
Reign SX
Year
2025
Price
$4,900
Category
Mountain
Sub Category
Downhill
Groupset
microSHIFT Advent X
Frame
Frame
ALUXX SL-grade aluminum front and rear triangles, 165mm Maestro suspension, flip chip, 12x148mm thru-axle, 27.5-inch rear wheel compatible, flip chip - Maestro 3, integrated down tube storage
Suspension Fork
RockShox BoXXer, Charger 3 RC damper, 190mm, 20x110, custom tuned for Giant
Rear Shock
RockShox Vivid Base, lockout, 205/65
Suspension Type
Full
Drivetrain
Shift Levers
microSHIFT Trail Trigger Pro, 1x10
Rear Derailleur
microSHIFT Advent X
Cassette
microSHIFT Advent X, 11-48
Crank
Praxis Cadet HD M24, 32t, 165mm, 55mm chainline
Bottom Bracket
Praxis, press fit
Chain
KMC X-10
Wheels
Front Hub
[F] Giant MTB alloy, six-bolt, [R] Giant MTB alloy, 72 POE (Points of Engagement), six-bolt, HG driver body
Rear Hub
[F] Giant MTB alloy, six-bolt, [R] Giant MTB alloy, 72 POE (Points of Engagement), six-bolt, HG driver body
Rims
Giant TRA 2 wheelset, 6061 alloy, hookless, 30mm inner width, 40mm outer width, 21mm height, Wide Guard Technology
Spokes
Sapim, 28, J-bend
Tires
[F] Maxxis Assegai 29x2.5 WT, 3C MaxxTerra, EXO+, TR [R] Maxxis Assegai 27.5x2.5 WT, 3C MaxxGrip, DD, TR tubeless
Brakes
Brake Type
Hydraulic Disc
Brake Description
TRP EVO DH-R, hydraulic, TRP rotors [F]220mm, [R]200mm
Brake Levers
TRP EVO DH-R
Cockpit
Stem
TruVativ Descendant Direct Mount 35, 50mm
Handlebar
Giant Contact SL TR35, 800x35mm, 20mm rise
Grips
Giant Tactal Pro Single
Seat
Saddle
Giant Romero
Seatpost
Giant Contact, 30.9mm, 400mm
Geometry
| Measurement | MD High | MD Mid | LG High | LG Mid | XL High | XL Mid |
|---|---|---|---|---|---|---|
| Stack Reach Ratio | 1.386 mm | 1.405 mm | 1.347 mm | 1.364 mm | 1.272 mm | 1.288 mm |
| Bottom Bracket Height | 336 mm | 330 mm | 336 mm | 330 mm | 336 mm | 330 mm |
| Front Center | 786 mm | 786 mm | 841 mm | 841 mm | 874 mm | 874 mm |
| Rake | 56 mm | 56 mm | 56 mm | 56 mm | 56 mm | 56 mm |
| Trail | 127 mm | 129.8 mm | 127 mm | 130 mm | 127 mm | 130 mm |
| Stack | 632 mm | 635 mm | 641 mm | 644 mm | 645 mm | 648 mm |
| Reach | 456 mm | 452 mm | 476 mm | 472 mm | 507 mm | 503 mm |
| Top Tube Length | 587 mm | 588 mm | 620 mm | 621 mm | 652 mm | 653 mm |
| Seat Tube Angle | 78.3 ° | 77.9 ° | 77.3 ° | 77 ° | 77.3 ° | 77 ° |
| Seat Tube Length | 425 mm | 425 mm | 450 mm | 450 mm | 475 mm | 475 mm |
| Head Tube Angle | 63.5 ° | 63.1 ° | 63.5 ° | 63.1 ° | 63.5 ° | 63.1 ° |
| Head Tube Length | 105 mm | 105 mm | 115 mm | 115 mm | 120 mm | 120 mm |
| Chainstay Length | 442 mm | 443 mm | 442 mm | 443 mm | 442 mm | 443 mm |
| Wheelbase | 1227 mm | 1228 mm | 1282 mm | 1283 mm | 1315 mm | 1316 mm |
| Bottom Bracket Drop | 19 mm | 25 mm | 19 mm | 25 mm | 19 mm | 25 mm |
| Standover Height | 742 mm | 737 mm | 755 mm | 750 mm | 771 mm | 766 mm |
| Wheels | 27" | 27" | 27" | 27" | 27" | 27" |
| Rider Min Height | 171 cm | 171 cm | 178 cm | 178 cm | 186 cm | 186 cm |
| Rider Max Height | 181 cm | 181 cm | 189 cm | 189 cm | 196 cm | 196 cm |




























































