Session 8 29 GX
Trek
Downhill
Session 8 29 GX is an alloy downhill mountain bike (2025), by Trek, in the Session series. It is a strong match for riders looking for a balanced off-road setup, with a balanced riding position, while being more at home in gravity-focused bike park riding. Standout strengths from the metrics include capable suspension support for rougher terrain and a balanced ride feel between comfort and directness. Compared with more specialized alternatives, the compromise is less emphasis on outright speed than speed-focused builds and a value score that depends more on priorities than pure price efficiency. Next step: compare this bike with other downhill models on MatchBikes.com.
6.4
Rating

+5
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Score Summary
Performance
6.7
Value
3.3
Fit
7.8
Performance
Built for speed and efficiency
Speed
2.5
Very Low
Climbing Efficiency
2.8
Hefty but Manageable
Suspension
10.0
Extreme rough-terrain ready
Fit
Dialed-in Fit & Comfort
Riding Position
6.8
Balanced
Fit Flexibility
6.7
Moderately Adjustable
Ride Comfort
8.7
Balanced
Value
Value for Money
3.3
Overpriced
Surface Range
Bike ParkSpecifications
General
Brand
Trek
Model
Session 8 29 GX
Year
2025
Price
$6,299
Weight
17.92 kg
Category
Mountain
Sub Category
Downhill
Groupset
Truvativ Descendant, GX
Frame
Frame
Alpha Platinum Aluminum, high main pivot, idler pulley, integrated frame protection, internal or external routing, magnesium rocker link, Mino Link, ISCG 05 2-bolt mount, Active Braking Pivot, 157x12mm thru axle, 200mm travel
Suspension Fork
RockShox Boxxer, DebonAir+ spring, Rush RC damper, 52mm offset, BoostDH 110x20 Maxle Stealth, 200mm travel
Rear Shock
Size: R1, Marzocchi Bomber, 400lb spring, 250mm x 72.5mm; Size: R2, Marzocchi Bomber, 450lb spring, 250mm x 72.5mm; Size: R3, Marzocchi Bomber, 500lb spring, 250mm x 72.5mm
Suspension Type
Full
Drivetrain
Shift Levers
SRAM GX DH, 7 speed
Rear Derailleur
SRAM GX DH, medium cage
Cassette
SRAM PG-720, 11-25, 7 speed
Crank
Truvativ Descendant DH, DUB 83, 34T steel ring, 165mm length
Bottom Bracket
SRAM DUB, 83mm, BSA threaded
Chain
SRAM PC-1110, 11 speed
Wheels
Rims
Front: Bontrager Line DH 30, Tubeless Ready, 6-bolt, 110x20mm Boost thru axle, 29'', Rear: Bontrager Line DH 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Shimano 7 speed freehub, 157x12mm thru axle, 29''
Tires
Bontrager G5 Team Issue, wire bead, 2-ply 60 tpi, 29x2.50''
Brakes
Brake Type
Hydraulic Disc
Brake Description
SRAM CODE Bronze 4-piston hydraulic disc
Cockpit
Stem
Bontrager Line Pro, 35mm, Direct Mount, 50mm length
Handlebar
Bontrager Line, alloy, 35mm, 27.5mm rise, 780mm width
Grips
Bontrager XR Trail Elite, nylon lock-on
Seat
Saddle
Bontrager Arvada, hollow chromoly rails, 138mm width
Seatpost
Bontrager Rhythm Elite, 31.6mm, 0mm offset, 330mm length
Geometry
| Measurement | R1 High | R1 Low | R2 High | R2 Low | R3 High | R3 Low |
|---|---|---|---|---|---|---|
| Stack Reach Ratio | 1.418 mm | 1.452 mm | 1.343 mm | 1.374 mm | 1.271 mm | 1.296 mm |
| Bottom Bracket Height | 359 mm | 350 mm | 359 mm | 350 mm | 359 mm | 350 mm |
| Front Center | 808 mm | 808 mm | 833 mm | 833 mm | 861 mm | 861 mm |
| Rake | 47 mm | 47 mm | 47 mm | 47 mm | 48 mm | 47 mm |
| Trail | 131 mm | 136 mm | 131 mm | 136 mm | 132 mm | 136 mm |
| Stack | 634 mm | 639 mm | 634 mm | 639 mm | 634 mm | 639 mm |
| Reach | 447 mm | 440 mm | 472 mm | 465 mm | 499 mm | 493 mm |
| Top Tube Length | 586 mm | 587 mm | 617 mm | 618 mm | 652 mm | 653 mm |
| Seat Tube Angle | 77.1 ° | 76.5 ° | 77.1 ° | 76.5 ° | 77.1 ° | 76.5 ° |
| Seat Tube Length | 425 mm | 425 mm | 425 mm | 425 mm | 425 mm | 425 mm |
| Head Tube Angle | 63.6 ° | 63 ° | 63.6 ° | 63 ° | 63.6 ° | 63 ° |
| Head Tube Length | 117 mm | 117 mm | 117 mm | 117 mm | 117 mm | 117 mm |
| Chainstay Length | 435 mm | 439 mm | 441 mm | 445 mm | 448 mm | 452 mm |
| Wheelbase | 1243 mm | 1246 mm | 1274 mm | 1277 mm | 1309 mm | 1312 mm |
| Bottom Bracket Drop | 12 mm | 21 mm | 12 mm | 21 mm | 12 mm | 21 mm |
| Standover Height | 755 mm | 747 mm | 759 mm | 751 mm | 757 mm | 749 mm |
| Wheels | 29" | 29" | 29" | 29" | 29" | 29" |
| Rider Min Height | 161 cm | 161 cm | 173 cm | 173 cm | 186 cm | 186 cm |
| Rider Max Height | 176 cm | 176 cm | 188 cm | 188 cm | 196 cm | 196 cm |




























































