With its new electrified Slash+, Trek is the latest big brand to join the likes of Mondraker with its Dune, Specialized with its Kenevo SL, and YT with its Decoy SN, in introducing a motor-assisted mid-power enduro bike. From being a relatively small niche just a couple of years ago, now the next generation of enduro bikes are here – will they make the best high end analogue enduro bikes extinct? Our guess is yes, but we’re getting ahead of ourselves. Let’s get back to the new Slash+. What are the details of this exciting new model?

The Trek Slash+ effectively mirrors its analogue namesake, but it’s less expensive.

Trek Slash+ need to know

• High-pivot enduro bike with 170mm travel
• TQ HPR 50 motor with 50Nm and 300w peak power
• Brand new TQ high-capacity 580Wh battery – the first bike to have it!
• 160Wh range extender also available
• Battery is easily removable
• MX wheels on M/L/XL and 27.5in front and rear on Small
• Two models: Slash+ 9.7 at $7,999.99 and Slash+ 9.9 at $11,999.99
• Bike weights from 20.38kg claimed

We just had the analogue Trek Slash on test, and we loved it – although we did suffer some issues with the lower chain guide pulley – so what has Trek kept from that bike, and what has it changed? Overall, the Slash+ is remarkably similar to the non-assisted version. The new bike also has a high-pivot suspension layout, it also gets 170mm of travel, a carbon frame, MX wheels, and loads of adjustability. But instead of a BITS down tube storage compartment, there’s a 580Wh removable TQ battery. Rather than a M/L frame size, there’s a medium, and a large – along with a new small option – where the reach has been tweaked to cover the gap filled by the M/L analogue frame.

That high-pivot design generates a rearward axle path, but requires an idler pulley and elaborate chain device to work, which has implications for efficiency and robustness.

Frame design and suspension

The Slash+ is a burly bike, but it also does a great job of disguising the fact it’s an e-bike. For that it owes a lot to the miniature TQ motor and slimline battery, but Trek has also continued the good work it did with the stealthy Fuel EXe and applied that prowess in concealment to the Slash+.

As with the Slash, the suspension uses a high-pivot layout, where the chainstays are elevated and the seatstays drive a rocker link. There’s a lot to fit in here, with the main pivot, ilder, rocker link, and hefty big can air shock – in this case the excellent RockShox Vivid Air.

Space inside the front triangle means you can run a water bottle or a range extender.

The front triangle also has to multitask; it has to house the battery, allow it to be slid out for charging or refreshing, give good standover for manoeuvrability, space for a water bottle/range extender, and pleasing aesthetics. Trek has managed to tick all those boxes, even making sufficient space on the S frame to run a water bottle/range extender and enough standover height for a 5ft 1in rider.

Both models available at launch use an OCLV carbon frame, but it’s likely that Trek will follow the path of the Fuel EXe by offering an alloy version further down the line.

The Trek Slash+should be right at home on chunder and chop.

A true high-pivot, rather than a halfway-house mid-pivot design, the Slash+ has a rearward axle path for most of its travel. But this does reduce chain wrap around the chainring – an important consideration when you have the extra power and torque of a motor present – so there’s an elaborate lower chain device and roller to extend the chain around the chainring. This roller is cantilevered off the chain device, and sits close to the rear tyre, so is quite vulnerable to damage. Hopefully Trek has made this part as robust as possible.

There’s also a large 19T idler pulley positioned close to the main pivot to tune the anti-squat and reduce pedal kick-back. This also needs to be durable, as e-bike typically add wear to a drivetrain, and may also have an impact on the power of the motor by increasing drag. Two things we’ll be keen to investigate when we get to ride the new bike.

Two-position lower shock mount gives progressive and more progressive leverage curves.

Trek has also carried over the leverage rate adjustment from the analogue Slash. This flip chip in the lower shock mount is designed to give riders a choice of suspension feel, as well as accommodate both coil and air-sprung shocks. In the forward position there is less progression, suited to air shocks, and the more rearward position increases ramp up, making it ideal for coil shocks.

Surprisingly there is still quite a lot of anti-squat on the Slash+ to keep the pedalling performance efficient. The curve is over 100% for the whole travel – although Trek doesn’t reveal which gear this is in.

Kudos to Trek for routing the cables through separate ports in the frame rather than through the headset, as this will make life much easier for, among other things, changing geo and servicing the headset.

That TQ motor is virtually invisible and barely audible.

Motor and battery

The Fuel EXe was the first bike to come with TQ’s exceptionally compact and quiet HPR 50 motor, and Trek builds on this relationship by selecting it for the Slash+ – notably the first bike to come with TQ’s brand new, bigger 580Wh battery. It’s a significant upgrade for the Slash+, as one of the main disadvantages with the TQ system is that it binges battery power, limiting range, particularly in the higher power modes needed to keep up with riders on full-fat e-bikes. This new battery should significantly increase the usable range without resorting to measly eco modes and relying on range extenders. That said, the Slash+ is also compatible with TQ’s 160Wh range extender, bringing the total potential battery capacity up to 740Wh.

We like the fact that the battery can be removed easily – just remove two bolts – meaning that it can be charged inside, or you can swap out a flat battery for a fresh one to keep on riding. Even the old 360Wh units will fit, once an extender block is bolted on.

Don’t expect to be razzing up climbs like a full fat e-bike, but the Trek Slash+ will definitely be more pleasurable uphill than the analogue Slash.

How much the high-pivot’s less efficient drivetrain will impact power and range remains to be seen. The other headline stats for the TQ’s harmonic ring transmission system are 50Nm peak torque and 300W peak power, so it’s definitely at the lower end of the best mid-power motor systems, sitting alongside the Specialized 1.1 rather than the punchier Fazua Ride 60 and Bosch SX.

If power isn’t the TQ’s greatest asset, volume, size, and weight are. This is the lightest big name motor on the market at just 1.85kg, it’s seriously small, making frame manufacturers’ jobs easier when it comes to packaging, and it’s virtually silent in use.

Integrated into the top tube is TQ’s large display, feeding back all sorts of information on range, speed, distance, cadence, and power. To switch between power modes, initiate walk mode, and even turn on lights (if fitted), there’s a discreet controller on the bars.

MX wheels should make the Slash+ pretty agile, but the sizing does have a bit of a gap between the large and XL frame.

Sizing and geometry

As we’ve already pointed out, the Slash+ comes in four frame sizes, deviating slightly from its analogue cousin by adding a size small, and ditching the in-between M/L. There are three geo options, tunable by changing the headset cups. In the neutral setting the head angle is 63.4º, dropping to 62.6º in the slack, and 64.2º in the steep position. The reach goes from 430mm for the small, to 449mm in the medium, 479mm large, and leaps to 519mm for the XL. Seat tube lengths are 390mm, 400mm, 435mm, and 470mm. BB heights are 352mm and the chainstays are 434mm on all but the XL, which gets longer 439mm stays. Finally, the effective seat angle is pretty steep at 77º.

The biggest potential sticking point here is the huge jump from the large frame to the XL. Riders in the 6ft zone might end up falling through the cracks a little here.

Trek Slash+ 9.9 comes in at £11,000.

Model range, specs, and pricing

There will be two models available at the time of launch. These are the Slash+ 9.9 and the Slash+ 9.7. The flagship Slash+ 9.9 will come with SRAM X0 AXS T-Type, a RockShox Zeb Ultimate fork, Vivid Ultimate shock, and SRAM Maven brakes, and the price is £11,000 / $11,999.99 USD. Claimed weight is 20.88kg (no indication of which frame size this refers to).

At £7,500, the Trek Slash+ 9.7 is the entry-level model, for now.

The Slash+ 9.7 has a Shimano SLX/XT mechanical drivetrain, Fox 38 Float Rhythm fork and Float X shock, and Shimano Deore four-piston brakes. It will cost £7,500 / $7,999.99 USD. Both bikes will come with the 580Wh battery as standard (but no range extender) and the same OCLV carbon frame. Claimed weight is 20.38kg.

Compare these prices with the analogue Slash, and they either make the e-bike look great value, or the unassisted bike hugely overpriced. For example, the Slash 9.9 with very similar spec (albeit it does get a pricier drivetrain) is £11,750. So the e-bike is actually £750 cheaper! Despite the battery, motor, display, and all the extra tech involved. For the Slash+ 9.7 there isn’t really a direct comparison, but the e-bike is only £50 more than the RockShox-equipped 9.7. We know which we’d choose.

trekbikes.com