Issue #037, Review -

Trek Slash 9.9 review

The Trek Slash seems to be a permanent fixture in our group tests and we look forward to testing it every time. For 2019, Trek has specced the bike with very high-end componentry. Will that be enough to catapult the now somewhat dated frame back to the top?

For an overview of the test fleet head to: The best enduro bike you can buy

Trek Slash 9.9 | 160/150 mm (f/r) | 13.26 kg | € 7,499

The Trek Slash was one of the first proper 29″ enduro bikes and it’s got a huge fan base. Although the frame itself has not changed since its launch in 2016, Trek updated the bike last year with their Thru-Shaft shock, developed in cooperation with Penske Racing. For the new season, the Slash now comes with lots of top-notch componentry. The € 7,499 top-end model features a sensitive FOX Factory GRIP2 fork and sturdy Shimano XT four-piston brakes. Shifting is taken care of by a SRAM GX/X01 Eagle drivetrain, and a set of lightweight Bontrager Line Carbon 30 wheels directly translate the rider’s power into forward propulsion. The Bontrager Line dropper seat post has been redesigned and now offers 150 mm travel. The Slash is also available in two colour options for 2019 – a svelte matte-black like our test bike or the colourful Miami paint job.

The Trek Slash 9.9 in detail

Fork FOX 36 FLOAT Factory 160 mm
Shock RockShox Deluxe RT3 Thru Shaft 150 mm
Brakes Shimano Deore XT Vierkolben
Drivetrain SRAM X01 Eagle
Seatpost Bontrager Line 150 mm
Stem Bontrager Line Pro 50 mm
Handlebar Bontrager Line Pro OCLV Carbon 780 mm
Wheels Bontrager Line Carbon 30 29″
Tires Bontrager SE4 Team Issue 2.4″
Weight 13.26 kg
Price € 7,499

Lots of traction
With Trek’s Thru Shaft shock, the piston rod moves downward through the shock during compression. As a result, no oil is displaced and it doesn’t need a reservoir. Fewer pressure seals also significantly reduce the amount of friction in the system.
Top class
The matte-black frame with its clean lines still looks amazing.
The Knock Block prevents the fork from damaging the down tube but it also makes it difficult to load the bike into the back of your vehicle. It’s more of an annoyance than a feature to us.
A lot of power
The Shimano XT four-piston brake convinces with lots of power and reliability. However, you must bleed them meticulously, otherwise, the bite point becomes inconsistent.

THe geometry of the Trek Slash 9.9

Size 15.5″ 17.5″ 19.5″ 21.5″
Top tube 590 mm 605 mm 635 mm 661 mm
Head tube 100 mm 100 mm 110 mm 125 mm
Head angle 65.6/65.1° 65.6/65.1° 65.6/65.1° 65.6/65.1°
Seat angle 74.1/ 73.6° 74.1/ 73.6° 74.1/ 73.6° 74.1/ 73.6°
Chainstays 433/434 mm 433/434 mm 433/434 mm 433/434 mm
BB hight 352/345 mm 352/345 mm 352/345 mm 352/345 mm
Wheelbase 1171/1172 mm 1186/1187 mm 1219/1219 mm 1247/1248 mm
Reach 416/410 mm 431/430 mm 459/445 mm 481/475 mm
Stack 608/612 mm 608/612 mm 618/628 mm 631/635 mm
Helmet Giro Switchblade | Goggle ETHEN ZEROQUATTRO | Shirt POC Raceday Jersey | Shorts POC Resistance DH Shorts | Shoes Specialized 2FO Cliplite

The Trek Slash 9.9 on the trail

In times when bikes are getting longer and longer, the 445 mm reach of the Slash seems somewhat outdated. But within the first few meters, it convinced our testers with one thing in particular, its balance. The balance of the bike is spot on despite the short reach and the weight distribution between the wheels is excellent. Riding input gets converted with immediate precision by the stiff bike. On tight trails, the Slash manoeuvres around corners with ease. However, when things get fast and bumpy, it takes a strong rider to keep the bike on track. The suspension works fine, but it is tuned rather firmly. If you ride actively and pump the bike, it will let you quickly build up a lot of speed. However, for those who are less fit, the bike will quickly tire you out.

Through its firm and direct setup, the Slash rewards active riders with plenty of speed.

The Slash accelerates very quickly out of corners and when you get on the pedals. In steep terrain, it remains unphased and due to the short front triangle, you can easily get your weight over the rear wheel. Despite the low weight of 13.26 kg, climbing with the Slash isn’t much fun because of the extremely slack seat tube angle. Despite shifting the saddle as far forward as it will go, the rider’s position is far over the rear wheel and you have to drop your upper body on steep climbs to shift your centre of gravity more to the front.

Tuning tip: Push the saddle all the way to the front


The Trek Slash is still a very good Enduro bike, scoring points for the excellent suspension and balanced handling. In the meantime, however, it’s noticeable that the geometry has become dated. The top-end version is specced with lots of carbon components which results in a rather harsh and demanding ride on fast descents.


  • Direct, lively handling
  • Super stylish look
  • Can be ridden actively


  • Demands a lot of energy from the driver
  • Uncomfortable climbing position





Value for money

For more info head to:

For an overview of the test fleet head to: The best enduro bike you can buy

All bikes in test: Bold Unplugged | Canyon Strive CFR 9.0 Team | Commencal META AM 29 SIGNATURE ORANGE | Giant Reign Advanced 0 | Lapierre Spicy Team Ultimate | Nukeproof Mega 275c RS | Orbea Rallon M-LTD I9 | Pivot Firebird 29 Team XX1 | Pole Machine EN | Santa Cruz Nomad CC | Scott Ransom 900 Tuned | Specialized S-Works Enduro 29 | YT Capra 29 CF PRO Race