Need to know

• New high pivot design and 19t idler, giving rear-ward axle path and increased anti-squat at over 100%
• Mixed wheel size now comes as standard, with a full 29er option and 27.5in front and rear in size Small only
• Travel up by 10mm to 170, like many of the best enduro mountain bikes 
• Geometry: head angle a degree slacker seat tube a shade stepper, and proportional chainstays across the sizes
• Mino link geo adjust is out, instead you get BB height adjust via a lower shock bracket and angle adjust headset
• Internal storage door made bigger, and internal cable routing concealed
• Seven models in the range, from £4,250 for the Slash 8 up to £11,750 for the Slash 9.9 AXS T-Type

Trek has been on it over the last few years, turning over old bikes and releasing updated models faster than you can say ‘enduro race ready’. The previous generation Trek Slash only came out in 2021, while the space in between has been filled by a reworked Fuel EX, the brand new lightweight Fuel EXe e-bike and an updated full-power Rail. Trek is going places, and it’s not hanging around.

Trek’s new Slash uses the high pivot design to add anti-squat at over 100% throughout the travel, ideal for keeping the bike’s shape under cornering, breaking or pedalling

High pivot design

The new Slash is a big jump from the old bike, with the most obvious change being a high pivot and idler: Something GT and Cannondale have also employed with the Force and Jekyll, and smaller brands like Forbidden and Norco have pioneered. Has Trek merely seized on the latest zeitgeist then, or are there real advantages to be gained, seconds won, and glaring holes filled from the old bike?

The benefits of running such a system are pretty well known now, Trek is better able to control the anti-squat, meaning the bike’s ability to resist compression under acceleration from pedalling or cornering. Indeed, the claims are more than 100% anti-squat throughout the travel of the bike, and very much in contrast with the old bike that lost almost all its anti-squat as it dived through the travel. There’s also a rearward axle path from the new high pivot design, without the associated chain growth and pedal kick-back problems, and the claim is suspension like this is better at eating square edged hits, like big rocks or roots.

Upper idler is a biggun, at 19T, the idea being to more efficiently deliver power to the rear wheel

The more complicated chain line will inevitably lead to more drag and weight, but Trek has worked hard at the former to minimise the impact with a huge 19T upper idler. That could well prove more efficient in terms of power transfer and less prone than other idler designs to becoming graunchy when stuffed full of grit and mud. The lower idler, nearly as big at an estimated 15T, is there to ensure the chainring has enough teeth engaged to pull the chain when you turn the cranks over. Trek says there are other benefits too, like reduced chain growth, smoother performance when pedalling and no tugging on the derailleur cage.

Slash by numbers

• 19 tooth upper idler
• 170 millimetres of travel, up 10mm
• 100 per cent anti-squat through the travel
• 488 millimetre chainstay, in size Large
• 200 millimetre dropper on size medium
• 29 inch front wheel, 27.5in rear

Trek’s moved away from 29in wheels front and rear to today’s trendy mullet setup, which does have some advantages in terms of wheel weight, strength and rear clearance, while the size small is 27.5in front and rear. Long live the diddy wheels.

• Which is the best wheel size? Mullet Vs 29er enduro bike

There’s also an option to go full 29er and gain more speed, with a bolt on lower shock bracket sold separately, although the snazzy new rear mudguard will have to come off. Trek has ditched its longstanding Mino Link angle geo adjust chip in part because of that bracket, which raises or lowers the bike’s BB height. There’s no need for the Mino Link either because there are angle-adjust headset cups as optional extras, to change the head angle by a degree.

That size small bike is actually a really cool addition, and one that can’t have been cheap for Trek with the need for additional frames and parts. The little bike will take a 170mm dropper post, still takes a water bottle, and might be ideal for radical rippers who think today’s bikes are too safe.

Geometry and sizing

The rest of us are well served with better geometry on the new bike, it’s half a degree slacker than the old Slash on the head tube, at 63.5°. Not much different, but with the Fuel EX moving to 64.5° Trek clearly felt the need to put some distance between them. Travel is up too by 10mm, to 170, bringing the bike into line with the best big travel enduro bikes.

Frame storage is the same size, but the door’s bigger and the cables are no longer on show

Trek has gone to some effort to make riders feel at home across all its bikes too, with the Fuel EX, Slash and Top Fuel all sharing very close reach measurement – 450mm in size medium, or thereabouts, and 488mm on the size large Slash. It’s also added size-specific chainstay lengths so the bike can remain balanced fore and aft as you size up or down, and the seat tube angle is now a pedal-friendly 77°. The bike will now take a 200mm dropper even in size medium, meaning a taller rider could opt for the smaller bike now and still be in a good pedalling position. Finally, Trek’s improved the internal storage area with a bigger door, easier catch and hidden cables, while the rest of the frame gets new chainstay guard, two dual density and replaceable downtube guards, and an additional layer of carbon protection underneath the paintwork.

The Trek Slash range

Slash 8 £4,250
Alloy frame, Fox Rhythm Float 36 fork, Fox Performance Float X shock, Bontrager Line Comp wheelset, Shimano XT 12speed drivetrain, Shimano 4-pot brakes

Slash 8 uses an alloy frame, and it looks almost as sleek as the carbon version

Slash 9 GX AXS T-Type £5,175
Alloy frame, RockShox ZEB Select+ fork, RockShox Vivid Select+ shock, Bontrager Line Comp wheelset, SRAM AXS 12speed drivetrain, SRAM Code Bronze 4-pot brakes

Slash 9.8 GX AXS T-Type £7,500
Carbon frame, RockShox ZEB Select+ fork, RockShox Vivid Select+ shock, Bontrager Line Elite 30 wheelset, SRAM GX AXS 12speed drivetrain, SRAM Code Bronze 4-pot brakes

Slash 9.8 XT £7,425
Carbon frame, RockShox ZEB Select+ fork, RockShox Vivid Select+ shock, Bontrager Line Elite 30 wheelset, Shimano XT 12speed drivetrain, Shimano 4-pot brakes

Slash 9.9 XTR £10,800
Carbon frame, RockShox ZEB Ultimate fork, RockShox Vivid Ultimate shock, Bontrager Line Pro 30 wheelset, Shimano XTR 12speed drivetrain, Shimano XTR 4-pot brakes

Slash 9.9 X0 AXS T-Type £9,400
Carbon frame, RockShox ZEB Ultimate fork, RockShox Vivid Ultimate shock, Bontrager Line Pro 30 wheelset, SRAM XO AXS 12speed drivetrain, SRAM Code Silver 4-pot brakes

Slash 9.9 XX AXS T-Type £11,750
Carbon frame, RockShox ZEB Ultimate Flight Attendant fork, RockShox Vivid Ultimate shock, Bontrager Line Pro 30 wheelset, SRAM XX AXS 12speed drivetrain, SRAM Code Ultimate 4-pot brakes

Big as a barn door, with 170mm travel front and rear

Hype pivot?

Working a high pivot idler into the new Slash is an interesting decision from Trek, particularly as the old bike was so darned good and descended so competently – an mbr test winner, no less. Perhaps the intention was to improve pedalling efficiency, help the bike ride higher in its travel, or merely keep up with the latest trends. We won’t know until we ride it, all we can say for now is that there are good and bad high pivot bikes, but with the Slash’s pedigree we’re betting it’s the former.