2018 Trek Slash 9.8
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Where To Buy
Free standard shipping on all bikes (continental U.S. only).
Flat rate shipping to Hawaii and Alaska.
Free standard shipping on all bikes (continental U.S. only).
Flat rate shipping to Hawaii and Alaska.
$6,299.99
Slash 9.8 XT
$6,299.99
Slash 9.8 GX
$6,299.99
Slash 9.8 GX AXS
$6,799.99
Slash 9.7
$4,249.99
Slash 9.9 XTR
$8,699.99
Slash 9.9 XO1
$8,549.99
Slash 9.9 XX1 AXS
$11,550.00
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
Review - 2018 Trek Slash 9.8 from Vital MTB Test Sessions
The Slash set the new benchmark for long-travel 29ers not long ago, and 2018's version attempts to meet the same standard. This one is stiff, light, and an excellent option for long adventures.
Rating:
Vital Review

During the 2018 Vital MTB Long-Travel 29er Test Sessions, the Trek Slash went head-to-head with four other leading bikes. What follows are our thoughts specific to the Slash. Be sure to check out the main feature for an in-depth comparison video, timed testing results, and more.

Highlights

  • OCLV Mountain carbon main frame and seatstays, alloy chainstays
  • 29-inch wheels
  • 150mm (5.9-inches) of rear wheel travel // 160mm (6.3-inches) fork travel
  • EVO link suspension with ABP (Active Braking Pivot)
  • Trunnion style 230x57.5mm Metric shock with RE:aktiv and Thru Shaft
  • Straight Shot frame design with Knock Block frame defense
  • Mino Link adjustable geometry
  • Control Freak internal cable routing
  • Carbon Armor
  • Press Fit 92mm bottom bracket with ISCG05 mounts
  • 160mm rear brake post mount
  • Boost 148mm rear spacing with 12mm through axle
  • 1X-specific drivetrain
  • Measured weight (size 17.5, no pedals): 29.7-pounds (13.5kg)
  • Three year warranty with one year paint and decals
  • MSRP $5,500 USD

Strengths

Trek has spent a lot of time refining their bikes, and that shows with the current Slash's frame. It is beautifully made and has subtle improvements that are largely hidden from sight, like a clever way of preventing cable rattle and excellent mud clearance. They have increased frame stiffness with a unique headtube/downtube design, and their geometry strikes that oh-so-coveted balance between the ups and downs. Despite being the stiffest bike in our test, the Slash was far and away the lightest. The light weight, very efficient climbing manners, and inclusion of fast rolling tires and a high-engagement rear hub on Bontrager's Line Elite 30 wheels kept us feeling like we could ride it for miles and miles while tackling any climbing challenge.

Trek has also done an excellent job with the Slash's ride-ability in the slow speed arena. That isn't to say it is slow, far from it, but it feels more lively than its travel and geometry numbers would indicate. That's a good thing, because some riders out there are worried that going to a 'bigger' bike can simply erase the trail beneath you. That isn't the case with the Slash – it tells the rider exactly what is going on with the trail below without ever feeling harsh. During our timed testing, the Slash was one of the best bikes of the bunch in later, rougher segments of trail that were taxing on other bikes. The suspension is excellent at handling repeated medium-sized hits, and gave our bodies some assistance when we needed it most.

Weaknesses

The Slash's communicative chassis is of course fun to ride and feels lively, but it does come at the expense of never really feeling settled. We spent time riding the Slash at Trek's suggested 28% sag point, and never really got along with it when the trail pointed downhill. We tried some different pressures before settling on 32/33% sag, making the Slash feel far more comfortable close to our limits. At the recommended setting the bike feels like a cross country rig with some longer travel bits bolted to it, as opposed to a descending machine that was made to climb. Of course, both types of bike can be equally good for different people, but make no mistake, they are very different machines. The Slash feels as though it was born from the world of efficiency rather than all-out fun.

As far as bang for your buck goes, the Slash serves up a decent, but not great value. Most of that is in the frame, with excellent paint and thoughtful touches. We do have some complaints with the build kit, however, which seems to be this bike's weak link. First, the Bontrager Drop Line seatpost is far from awesome. With only 125mm of drop on the size 17.5 frame and a seat tube that doesn't allow for that low of an insertion, Trek is lagging behind many other bikes in this arena. The last thing you want when a bike exhibits that 'on top of' feeling rather than 'in' the bike is a saddle that doesn't get out of the way enough. Second, the 2.4-inch Bontrager SE4 Team Issue front tire lacks the locked-in performance traits of today's best rubber, which was especially notable in the steeps.

While the Knock Block system – which keeps the fork's crown away from the straightened downtube – is a bit limiting, we think the tradeoff is worthwhile for a frame that's so stout and light.

The unique Thru Shaft shock with Trek's RE:aktiv technology no doubt adds to some of the bike's most notable ride qualities, but we feel the lack of a worthwhile compression adjustment is a weakness. You can switch to pedal or firm modes, but in the open position we wish we could give the shock some more damping support to counteract the bike feeling a little unsettled at times.

Suggested upgrades for a few hundred dollars: We'd immediately pick up a more appropriate front tire, like the Bontrager SE5, then we'd put the rest toward a longer travel dropper post.

Geometry

Suspension Analysis

Using the bike industry's leading linkage analysis software, André Santos was able to determine a close approximation of the Slash's kinematics for the purpose of this review. Though they don't always tell the full story, these charts provide great insight into several key factors that impact how it rides.

André's Observations:

  • The Slash has good progressivity at 27%, meaning that the frame offers natural resistance against bottom-outs.
  • There's great pedaling efficiency with stable anti-squat values at nearly 100% on the pedaling zone for most rear cogs.
  • The amount of chain growth and pedal kickback are normal for the segment.
  • Anti-rise of 50%, meaning that there is a good balance between geometry and traction under rear braking.
  • Overall, the Slash is a moderately progressive bike with great pedaling efficiency.

Vital's preferred suspension settings for a 175-pound rider on stock components: 32% sag // LSC - Full open

What's The Bottom Line?

Of all the bikes in the test, the Slash is the best suited to all-day adventures. It is very easy to ride and can still do just about anything. It was also surprisingly good in a timed run. While not the fastest overall and a little unsettled feeling at times, the feedback was so clear that it was easy to tell where the limits of the bike were. It is easy to think you want a bike that gobbles up everything or that is the raddest out there, but the Slash is just a really easy bike to live with. The more time we spent on it, the more trust we built up. If you are the type that wants to cover a lot of ground and tackle tough sections from time to time, the Slash can fit that bill and leave you feeling fresh when the time does come to step up and ride the big lines. With a few component swaps this one lives up to its former glory.

Visit www.trekbikes.com and the 2018 Vital MTB Long-Travel 29er Test Sessions feature for more details.

Vital MTB Rating


About The Testers

Steve Wentz - Age: 33 // Years Riding: 21 // Height: 5'8" (1.73m) // Weight: 174-pounds (78.9kg)

"Despite what it looks like, I'm really precise and calculated, which I'm trying to get away from. I'm trying to drop my heels more and just let it go." Steve is able to set up a bike close to perfectly within minutes, ride at close to 100% on new trails and replicate what he did that first time over and over. He's been racing Pro DH for 15+ years including World Cups, routinely tests out prototype products, and can squish a bike harder than anyone else we know. Today he builds some of the best trails in the world.

Brandon Turman - Age: 31 // Years Riding: 16 // Height: 5'10" (1.78m) // Weight: 175-pounds (79.4kg)

"I like to have fun, pop off the bonus lines on the sides of the trail, get aggressive when I feel in tune with a bike, and really mash on the pedals and open it up when pointed downhill." Formerly a Mechanical Engineer and Pro downhill racer, Brandon brings a unique perspective to the testing game as Vital MTB's resident product guy. He has on-trail familiarity with nearly every new innovation in our sport from the past several years and a really good feel for what's what.

Photos by Luca Cometti // Video by gordo with assistance from Suspended Productions

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Specifications

Product
Trek Slash 9.8
Model Year
2018
Riding Type
Enduro / All-Mountain
Rider
Unisex
Sizes and Geometry
15.5 in.
17.5 in.
19.5 in.
21.5 in.
Wheel Size
29"
Frame Material
Carbon Fiber
Frame Material Details
OCLV Mountain Carbon main frame and seatstays, alloy chainstays, Carbon Armor
Rear Travel
150mm
Rear Shock
RockShox Deluxe RT3, RE:aktiv with Thru Shaft 3-position damper, tuned by Trek Suspension Lab, 230mm x 57.5mm
Fork
FOX Performance 36 Float, GRIP 3-position damper, E2 tapered steerer, Boost110, G2 Geometry, 51mm offse
Fork Travel
160mm
Head Tube Diameter
Tapered, 1.125" top, 1.5" bottom
Headset
Knock Block Integrated, sealed cartridge bearing
Handlebar
Bontrager Line Pro, OCLV Carbon, 35mm clamp, 27.5mm rise, 780mm width
Stem
Bontrager Line Pro, Knock Block, 35mm clamp, 0° rise, 50mm length
Grips
Bontrager Rhythm, dual lock-on
Brakes
SRAM Guide RS hydraulic disc
Brake Levers
SRAM Guide RS hydraulic
Drivetrain
1x
Shifters
SRAM GX Eagle, 12-speed
Front Derailleur
N/A
Rear Derailleur
SRAM GX Eagle, Roller Bearing Clutch
ISCG Tabs
ISCG05
Chainguide
N/A
Cranks
SRAM Descendant 7k Eagle
Chainrings
SRAM Descendant 7k Eagle, 32 tooth, Direct Mount, X-Sync
Bottom Bracket
PF92
Pedals
N/A
Chain
SRAM GX Eagle
Cassette
SRAM GX Eagle, 10-50 tooth, 12-speed
Rims
Bontrager Line Elite 30, Tubeless Ready (tubeless strips included, valves sold separately)
Hubs
Bontrager Line Elite 30, 108T Rapid Drive, Boost110 front, Boost148 rear
Spokes
 
Tires
Bontrager SE4 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 29" x 2.40"
Saddle
Bontrager Evoke 2, chromoly rails
Seatpost
Bontrager Drop Line, internal routing
15.5": 100mm travel, 17.5": 125mm travel, 19.5" and 21.5": 150mm travel
Seatpost Diameter
31.6mm
Seatpost Clamp
Standard single bolt
Rear Dropout / Hub Dimensions
148x12mm Boost
Max. Tire Size
 
Bottle Cage Mounts
Yes (single)
Colors
Trek Black/Roarange
Warranty
3 years frame and swing arm, 1 year paint and decals
Weight
29 lb 11.1 oz (13,470 g)
Miscellaneous
EVO link suspension
ABP (Active Braking Pivot)
Straight Shot frame design
Knock Block frame defense
Mino Link adjustable geometry
Control Freak internal cable routing
1x-specific stays
Price
$5,499.99
More Info
What do you think?
Where To Buy
Free standard shipping on all bikes (continental U.S. only).
Flat rate shipping to Hawaii and Alaska.
Free standard shipping on all bikes (continental U.S. only).
Flat rate shipping to Hawaii and Alaska.
$6,299.99
Slash 9.8 XT
$6,299.99
Slash 9.8 GX
$6,299.99
Slash 9.8 GX AXS
$6,799.99
Slash 9.7
$4,249.99
Slash 9.9 XTR
$8,699.99
Slash 9.9 XO1
$8,549.99
Slash 9.9 XX1 AXS
$11,550.00
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
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