Trek Marlin+ 8 hardtail eMTB mixes business with pleasure [Review]

I never really understood the appeal of hybrid bikes. The cheap, flat bar frankenbikes just aren’t fun to ride on the road or the trail. In a way, the Trek Marlin+ 8 is a new-age type of hybrid bike — fully mountain but also suited to running errands around town. Would it be fun and capable, or would it be a dud like the hybrid road/mountain bikes I’ve come to loathe? I spent the past several weeks riding one on the trail and the road to find out.

Trek Marlin+ 8 key specs

• Hardtail with 120mm RockShox Recon Silver RL fork
• Geometry highlights: 66.5° head tube angle, 74° seat tube angle, 470mm reach (size large)
• Aluminum frame
• 400Wh Bosch battery and 50Nm motor
• Price: $3,499
• Buy from Trek

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Geometry and frame features

The Trek Marlin+ 8 geometry isn’t especially progressive, nor is it overly conservative. The 66.5° head tube angle feels appropriate given the bike’s 120mm of front suspension travel, and the 74° seat tube angle isn’t too far off from the average hardtail.

The 495mm reach on the size XL I tested is just right, especially considering the long, 485mm (!) chainstays. Electric mountain bikes tend to have longer chainstays than regular mountain bikes, but even among eMTBs the chainstay length on the Marlin+ is long. The upshot is a bike that’s stable at speed with a wheelbase that’s not crazy long.

Frame size letter	XS	S	M	L	XL
Wheel size	27.5″	27.5″	29″	29″	29″
Seat tube	340	370	420	450	500
Seat tube angle	73.8°	73.8°	73.8°	73.8°	73.8°
Effective seat tube angle	74.0°	74.0°	74.0°	74.0°	74.0°
Head tube length	90	100	105	115	135
Head angle	66.5°	66.5°	66.5°	66.5°	66.5°
Effective top tube	551	584	620	652	682
Bottom bracket height	313	313	318	318	318
Bottom bracket drop	45	45	60	60	60
Chainstay length	470	470	485	485	485
Offset	46	46	42	42	42
Trail	110	110	114	114	114
Wheelbase	1129	1166	1218	1251	1284
Standover	678	710	760	771	775
Frame reach	390	415	440	470	495
Frame stack	563	590	626	635	653

The Trek Marlin+ 8 that I tested has two sets of bottle mounts inside the front triangle, one of which can be used to mount an extra battery to extend the bike’s range. There are mounts for a rear rack (and a kickstand) as well, in a nod to the bike’s ability to serve double duty as a commuter.

The “Alpha Gold Aluminum” alloy frame features internal cable and brake hose routing. The battery is basically sealed inside the frame, so it’s not practical to remove it for charging, or to ride the bike without a battery. A burly chainstay protector comes mounted to the frame, and the rear dropouts are UDH-compatible.

My size XL test bike weighs about 21.9kg (48.2lb). It’s heavy for a hardtail, though there are certainly full-suspension electric mountain bikes that weigh much more than that.

Trek Marlin+ 8 build spec

Looking at the parts spec, the Trek Marlin+ 8 is clearly a mountain bike. Up front there’s a RockShox Recon Silver RL fork with 120mm of travel, and for those who aren’t familiar with entry-level RockShox suspension components, the key here is that the Silver RL is an air fork, and not a coil fork. So, while it’s not the most capable fork, it is adjustable, and this version is designed specifically for e-bikes.

The drivetrain is a mix of Shimano Deore and FSA parts with a 32T chainring and a 12-speed, 10-51T cassette. The 32T chainring is actually the minimum size that Trek recommends for this bike; it can fit up to a 36T.

The Marlin+ 8 uses a Bosch Active Line Plus motor capable of producing up to 50Nm of torque. Trek pairs the motor with a 400Wh Bosch CompactTube battery that I’ve found offers at least 30 miles of range on rolling, mixed surface riding with a medium-low level of assistance.

Shimano MT420 4-piston brakes with 203mm rotors front and rear deliver plenty of stopping power, and size medium through XL bikes ship with a 150mm TranzX dropper post. (Sizes small and extra small get 100mm of drop.) At the cockpit, the handlebar width is either 720mm or 750mm depending on the size of the frame.

Tubeless tires and rims round out the Trek Marlin+ 8 spec. Here, size small and extra small frames roll on 27.5″ wheels, while the larger sizes are on 29er wheels. Trek specs 2.6-inch-wide Bontrager Gunnison Pro XR tires that are billed as “all-around” trail tires.

Trek has another, lower spec build for the Marlin+, dubbed the Marlin+ 6. In terms of the components, the bikes are VERY different, and core mountain bikers or even those who plan to ride a little bit of singletrack will want to avoid the lower spec. Sure, the Marlin+ 6 is $800 cheaper, but it only has nine gears, no dropper post, tubeless-not-ready wheels and tires, and comes with a clunky coil fork.

On the trail

I found the Trek Marlin+ 8 to be a fun bike for most of my local rides. Here’s how most of the test rides went: start off in Eco mode and smash out a mile or two on the road to get to the first singletrack trail; switch into Tour+ mode for a little more assistance and faster acceleration out of the turns; pop out onto a road and go back into Eco mode; and repeat. The Bosch Active Line Plus system features an Auto mode that I used a bit, but it was hard to tell exactly what it was doing, so I opted to stick with the more straightforward assistance modes — Eco, Tour+, and Turbo.

The motor is generally very quiet on the trail unless you’re really grinding up a steep slope, and even then the whine is noticeable though not distracting like other e-bikes I’ve tested.

Reviewer profile height: 190cm (6’3″) weight: 75kg (165lb) testing zone: Southeast, USA

On climbs, the Trek Marlin+ 8 offers smooth, even assistance that doesn’t feel jerky or overly unnatural. I quickly found confidence starting from a stop and navigating more technical bits of singletrack where pedal stroke placement and speed management are key. The front wheel stays planted thanks in part to the somewhat steep head tube angle, and also the smooth power delivery from the motor.

Planted is also how I would describe the Marlin+ 8 on descents, but with an asterisk. It is a hardtail, after all, and a heavy one at that. The weight of the bike serves to keep the rear end firmly in contact with the ground, though it can be a rough and sometimes jarring ride through rocky, rooty trails. The wide, 2.6″ tires allowed me to tune the ride feel to a degree, but I found myself in a classic dilemma. I could reduce the pressure for a smoother ride and better handling, but then I worried I might bottom out the tires due to the weight of the bike. Indeed, the rear tire and/or rim must’ve suffered damage during testing because it no longer holds air very well even after adding ounces of fresh sealant.

I see why Trek specs the Bontrager Gunnison Pro XR tires on this build; they seem to be fairly lightweight and fast rolling, which surely improves the bike’s range. For singletrack trail riding, however, I found they’re under gunned, especially tearing into corners at electric-assisted speeds. If this were my bike, I’d upgrade the front tire to something knobbier, and the rear tire to something tougher.

Sure, the Marlin+ 8 is heavy compared to a non-electric bike, but it’s not impossible to get it off the ground. The Marlin+ 8 is fun to launch off roots and lips, especially with a little boost of acceleration from the motor. Aside from the leaky rear tire, the overall package has held up well to moderate trail riding.

The Bosch Purion 200 remote has a bright, colorful, and responsive screen, but dang, there are a lot of buttons (six, to be exact). Not only does this make toggling through the various screens and menus confusing, it also means more potential for accidental button presses during the ride. It took me several rides — and finally an adjustment to the orientation of the controls — to avoid changing the ride mode while reaching for the dropper post remote. Now I understand why the first message you see upon turning the system on reminds you to “Avoid distracted driving.” Maybe if the controls and screens were simplified I wouldn’t be so distracted.

I’m also not a fan of the charging port Bosch uses. You have to orient the plug just right in order for it to fit, and every time I have to guess and press repeatedly until it finally connects. Charge times tend to be slow enough that you should plan well in advance before riding. Alternatively, you could just keep it topped off after every ride.

Priced at about $3,500, the Trek Marlin+ 8 isn’t a cheap bike, and to get the most out of it I’d consider a couple of upgrades down the line — like a longer dropper post and better fork — as my budget allows. I’d definitely upgrade the tires on day one.

Trek bills the Marlin+ 8 as their “ultimate do anything e-MTB.” I think casual riders will agree with this statement, though core riders will recognize its limitations when it comes to faster, more gravity-oriented trail riding.

On the street

In general, mountain bikes make okay commuters, but lighter bikes with faster-rolling tires tend to work even better. But add a motor to a mountain bike, and you don’t really have to worry about weight or drag. I found the Trek Marlin+ 8 works well as an in-town commuter bike, and on flat roads it’s easy to cruise at the maximum assisted speed of 20mph. Even though I’d prefer to upgrade the tires for singletrack use, I found the Gunnison tires to be surprisingly quiet when riding on pavement. If this were my bike, I’d probably invest in a rack plus a rear light to get even more use out of the bike. Curiously, Trek says the Marlin+ 8 isn’t set up for a wired front light.

A fair number of neighbors have dedicated e-commuter bikes, but to me that seems like a waste of space and cash when you can own a bike like the Marlin+ 8 that works for both business and pleasure.

Pros and cons of Trek Marlin+ 8

Pros

• Comfortable commuter and fun bike for light-duty trail riding
• Capable, MTB-worthy parts spec
• Modern look and feel

Cons

• Entry-level fork isn’t very responsive
• Battery isn’t easily removable
• Tires are fast rolling but aren’t ideal for cornering or running lower pressures

Bottom line

The Trek Marlin+ 8 blends the practicality of an electric commuter bike with the fun factor of a light-duty mountain bike in a package that looks good and feels good too.