Trek’s new Slash sounds rock and roll and looks stunning, but does it go like a bat out of hell?
Travel on the Slash has been pumped up to 150mm and the geometry and sizing are bang up-to-date.
At present, the Slash 29 is only available with a full OCLV carbon frame and there are two flavours: the top-of-the-range 9.9 RSL that we’re testing here, and the RockShox-equipped 9.8 at £4,600.
One of the most obvious changes to the frame is the Straight Shot down tube.
The concept is simple: eliminate the gooseneck where the down tube joins the head tube and the frame can be made lighter, stiffer and stronger.
The only problem is that the fork crown can now hit the down tube.
Trek’s solution: the Knock Block steering lock. It’s a neat replaceable component in the headset that limits the steering, with back-up protection on the frame, just in case.
A less obvious change is that the shock is now mounted on bearings in the frame and upper link.
It’s a similar set-up to that used by Giant, and the benefits of the reduced friction are amazing small-bump sensitivity and increased grip.
So much so that the Slash 29 never felt like it had less travel than the other bikes in the test.
It’s also one of the only bikes equipped with a Fox Float X2 shock where we’ve actually had to add damping, rather than subtract it.
The Slash 29 gets a travel-adjustable fork, where the 36 Talas can be lowered from 160mm to 130mm with a quarter turn of a dial.
It’s simple and effective, but we’re not convinced that the Slash 29 needs it.
There’s also a price to be paid for having it, namely that the fork doesn’t offer the same level of support as the fixed-travel Fox 36.
There’s no faulting the RC2 FIT damper though, and we’re constantly impressed by the fork’s ability to iron out even the most stubborn creases in the trail.
This is where Trek starts to lose some ground. The carbon handlebar has a goofy profile that dips down at the ends and the saddle feels bulky and overly soft.
Also, because the Bontrager Drop Line seatpost only has 125mm of drop, it makes the saddle feel even more intrusive on steep technical descents.
With the frame having a super slack seat angle, it also puts a high load on the back of the post, and you can feel it grinding when you drop the saddle, which is probably why the cable snapped after only six or seven rides.
First ride out on the Slash 29 and we bottomed the rear suspension in the blink of an eye.
It turns out the shock runs a reduced stroke to achieve the desired amount of travel, and by simply eyeing up a third of travel on the Kashima-coated shock body, it meant that we were actually running closer to 50 per cent sag.
With the correct pressure, and an additional volume reducer, the harsh bottoming was eliminated, but that was just the beginning of our shock fettling.
We progressively added damping to the Fox Float X2 to help stabilise the suspension — it really is that sensitive — and make the Slash 29 more effective on the climbs.
Upping the compression damping also increases the effectiveness of the Open/Firm lever on the shock, which in turn helps prop up the rear end and offset the slack seat angle when winching up the steepest gradients.
It’s probably why Trek fitted the Talas fork, but a better solution would be a steeper seat angle, as pedal clearance is reduced when you lower the fork.
It’s clear that the Slash 29 wasn’t designed for climbing, though, it’s about slaying the descents.
Trek has done an amazing job with the new Slash 29. The geometry and sizing are both on the money, the feel of the carbon frame is solid without being too stiff, or jarring, and the grip that the rear suspension provides is on another level. Even though it’s a whopping £6k, in present company that represents pretty good value, given that you have Fox suspension and a 1x12 SRAM Eagle drivetrain. It’s a tricky bike to set up though, and there are aspects of the build kit, namely the handlebar and seatpost, that prevent the Slash 29 reaching its full potential.