Trying to decide whether to buy the Trek Marlin 4? Then you’ve come to the right place.

Buying a new bike is never easy. So I’ve got a ton of detailed info in this review to make the whole decision making process a little easier for you – basically I’ve got everything you need in this article to enable you to go, “Yep, this is the right bike for me”, or “Nope, gotta move along to the next one on the list”. Firstly, I’ve got a full spec list for the Marlin 4, listing every component, so that you can compare the bike against others. Either other bikes from the Marlin range (like the Trek Marlin 5 or the 6) or maybe even a different type of bike, such as the FX or Dual Sport ranges from Trek. I’ll then take you an in-depth write-up of the Marlin range, and the Marlin 4 in particular, so you can see what I think of this bike.

But, maybe you don’t have time for all that detail? Maybe you just want to know whether it’s a good bike, so you can either buy it or move on. Hey, I’m not going to be offended! Life is short and we’ve got bike rides to go on after all. So, here’s a quick spoiler. If you want a great entry-level mountain bike for light-duty trails, that’s also a great all-rounder and perfect for trips to the beach/grocery store or commuting to the office. AND you want all that at a stunningly-low price. Then the Marlin 4 is a great choice. If you want all that in a bike that’s a little lighter, a little more trail-ready, and you’ve got some extra coinage in your back pocket, then I’d suggest pushing the boat out slightly further and getting the Marlin 6.

Whichever Trek Marlin you choose, however, you’ll be riding around on it with a big grin on your face.

Now, spoiler over, if you’re able to stick around for a little longer we’ll go into a deep dive on the Marlin 4. Prepare to drool.

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Trek Marlin overview

Trek’s Marlin range of bikes are known as mountain bikes, MTBs (for those looking for something that’s a little less of a mouthful) or “hardtails” (for those looking to appear a little more intelligent). For the rest of us, it’s useful to know that hardtails are bikes that have suspension on the front forks, dampening the trail vibration before it reaches your hands, wrists and arms. Full-suspension or ‘full-sus’ bikes are mountain bikes that have suspension on both the front and rear forks. Unless you’re an intermediate to advanced mountain biker then I’d recommend steering clear of full-suspension bikes. Top-of-the-range full-sus bikes are fantastic to ride but they come with a hefty price tag. Full suspension bikes that are more affordable tend to have rear suspension that is lower quality (therefore more prone to failure) and heavier (so you’ll have a harder time pedaling up hills).

Hardtails, like the Marlin range, are a great all-rounder. They’re sufficiently rugged to get around most beginner-to-intermediate bike trails with ease (and a grin on the rider’s face) and they’ll also take you to places where full-suspension MTBs would be completely out of place: the beach, the grocery store, the park at the weekend, and the office during the week. And that makes them a really versatile option for many people.

Trek’s Marlin range encompasses seven different models. These go from the entry-level Marlin 4 through consecutive numbers to the top-of-the-range Marlin 8. With these male/unisex bikes being complemented by the female-specific, Marlin 5 Women’s and Marlin 6 Women’s.

When I was researching the Marlin range online, I came across one comment which really summed it up: “Bang for the buck!!!!” Clearer the owner of this Trek bike was very enthusiastic about his purchase, though I did feel that the fourth exclamation mark was a little over-the-top. But, whatever, all the Marlin models are great bikes.

And, not only are they great bikes, by they’re also fantastic value-for-money. From the Marlin 4 at a touch over $500 to the Marlin 8, which is only around $1200. I say ‘only’ because, in the world of mountain bikes this is an absolute bargain.

So, the Marlin range is a series of hardtail mountain bikes, with great specifications, at a range of price points, that all represent excellent value. Let’s dive in and take a closer look at the Trek Marlin 4.

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Trek Marlin 4 review

Pros: Lowest price in the Trek Marlin range; great ‘bang for your buck!!!!’
Cons: non-locking front suspension fork, narrower range of gears, heavier than other Marlins

Let’s start with looking at who this bike is for.

The Marlin 4 is a great all-rounder. It will take you on to plenty of backcountry trails, where you can have as much fun as you want on bike trails with loose stony or muddy surfaces. Returning home with a muddy grin on your face. Give it a clean down afterwards, pull on your work clothes, and it will take you to the office, with another grin plastered on your face (though, hopefully, less mud). In between, it will give you a lift to the beach, the grocery store, and around the local park to chase your kids.

If you’re new to cycling, then you’ll be hard pushed to find a better option than the Marlin 4, however you might not appreciate how versatile it is. Compare it to a road bike – the kind that you see spandex-clad speed merchants hunched over – or a full-suspension mountain bike and you’ll soon notice the differences. The Marlin 4 has a much more relaxed and upright riding position than a road bike does. Sure, you’re unlikely to go as fast as on a road bike, but you’ll ride in considerably more comfort. And you won’t be hitting the ‘Double Black Diamond’ bike trails on a Marlin 4, but then you might also have fewer trips to the Emergency Ward at your local hospital. Swings and roundabouts.

If you fit this description – you’re looking for an all-rounder bike and aren’t looking to achieve land speed records in your spandex or cycle down near vertical trails, then the Trek Marlin 4 is a great choice for you. If, however, you’re looking to spend more time on tougher and more rugged bike trails, then it’s worth heading a few notches up the range towards the Marlin 7 or Marlin 8.

Check out the specification list at the top of the page and you’ll see that the Marlin 4 has a great aluminum frame (which is light and strong) It has front suspension forks which reduce the amount of vibration from a bumpy trail surface from reaching your fingers and wrists. The Bontrager XR2 Comp tires give good grip and cornering on loose surfaces, and yet still feel smooth to ride when you’re on pavement. Top this off with 21 gears for getting you up hills easily and down hills quickly and you’ve got an excellent package.

The base model pricing of the Marlin 4 doesn’t come without a couple limitations though. First up, the Tektro disc brakes are mechanical rather than hydraulic. That means that they use a cable to pull the brake pads against the brake discs, rather than hydraulic brake fluid. These are still great brakes, giving you all the stopping power you need, however they add weight to the bike vs their hydraulic siblings. And bike weight is the second issue. Compared with the more expensive Marlin 8, the Marlin 4 is nearly three pounds heavier. Cycle for long distances or up lots of hills and you’ll definitely notice this extra weight. But, then, if you have the funds available and want extra spec, there are plenty of more advanced models in the Marlin range to choose from (Hint: I love the Marlin 6).

To sum up, if you’re looking for a great first bike for all-round use, taking you on regular trips to the trails, parks, beaches, and office, then the Marlin 4 is an awesome choice.

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What is the difference between Trek Marlin 4 and 5?

One step up from the Trek Marlin 4 is the Marlin 5. With just over a hundred-dollar difference, is it worth stumping up the extra cash to trade-up?

Well, there are some general improvements to the components on the Marlin 5. With the key ones to note being the front forks, gearing, and brakes. Suspension on the front forks can now be locked. That means you choose when the forks are bouncy (to soak up rough terrain) or fixed (to make it easier to throw your weight behind uphill ascents). It’s a feature that I’m a big fan of.

Gearing has been changed so that, instead of 3×7 on the Marlin 4, there are now 2×8 on the Marlin 5. There are fewer gears, although in practice you won’t notice this. What you may notice is that there are likely to be fewer mechanical issues with 2-ring gearing than 3-ring in the long term – fewer issues meaning less downtime and less repair cost.

Finally, the brakes on the Marlin 5 use hydraulic brake fluid rather than the cable-pull mechanicals of the Marlin 4 brakes. These are lighter and are what you find on high-end mountain bikes.

Are these worth paying the extra for? Well, I ride a hardtail mountain bike that has a locking front suspension and it’s a feature that I really like as I use my bike on plenty of uphill smooth surfaces (as well as rougher trails). Doing those same uphills without locking suspension is harder but if your uphills are few are far between then this may not be an issue for you and therefore not worth paying for.