Trek Marlin 4 Review – Is This Bike Worth Buying?

Mountain bikes can be expensive. If you’ve looked casually at the mountain bike market you probably saw bikes that cost many thousands of dollars. Some potential riders look at these prices and give up. That’s a mistake. Many credible manufacturers make solid, affordable bicycles that can serve as both entry-level mountain bikes and day to day transportation. Some of these bikes cost as little as $500. The Trek Marlin 4 is a leading contender at this price point.

The Trek Marlin 4 is a simple, straightforward bicycle. It’s still a machine that shows real quality. The bike uses components from major manufacturers that make some of the best parts you can buy. That expertise filters down to the entry level components, and while you can’t expect a $500 bike to match a $5000 bike in every way, you might be very pleasantly surprised by what you can do with an entry-level mountain bike.

Image Source: Trekbikes.com

Quick Overview: What I Think of the Trek Marlin 4

Like any entry-level bike, the Trek Marlin 4 has to be rated by its intended purpose and its price point. This is not a high end bike. If you want a bike for cross country racing or aggressive riding on technical trails, this isn’t it. This is a bike designed as an affordable starting point to cycling that can serve double duty as a daily transport bike and an entry level trail bike. It fulfills those functions very well and provides real value for money.

If you look at the Trek Marlin 4 as the next step up from the off-brand bikes that sell for $300-400 at big box stores you get a sense of the value the bike brings. The Marlin 4 represents a huge step up from the bikes that are one tier below it. This is a real mountain bike from a credible manufacturer. It may be one of their least expensive models, but if you’re in the market for an affordable bike you will get a whole lot more from the Marlin 4 than you would from a bike only slightly cheaper.

If you want a bicycle and you have only $500 to spend this would be an excellent way to spend it. It won’t perform like a $5000 bike, but it will be far, far, better, than a $400 bike.

Review Category
Rating Out Of 5
Components
3.5
Build Quality
4
Ride Quality
4
Overall Value for Money
5

What You Get

Key to when looking at buying any bike, is looking at the frame components and how good they are. Let’s look at the key components of the Marlin 4.

Frame

The Marlin 4 frame is made of aluminum.. Trek has been making high-end aluminum frames for decades, and that experience shows in their entry-level frames. The Marlin 4 frame is not the lightest on the market, but the welds are clean and solid, the paint job is first class, and the frame looks like something you’d find on a much more expensive bike. The cables that control the brakes and gear shifting are routed inside the frame tubes, which keeps the outside clean and uncluttered and reduces the likelihood of damage.

The small and extra small Marlin 4 frames feature a top tube that curves down, decreasing the bike’s standover height and making it easier to straddle the bike without the frame hitting you in the crotch. That’s a detail that smaller riders will appreciate.

Suspension

The Marlin 4 carries a front suspension fork from SR Suntour, a leading Japanese producer of mountain bike suspension. SR Suntour forks lack the light weight and multiple adjustments of high end mountain bike forks, but they absorb impact and they stand up to abuse. The SR Suntour XCE fork on the Marlin 4 may not set you up for huge hucks or win you bling points at the bike shop, but it will soak up the chatter and take impacts off your hands and arms.

The suspension travel on the Marlin 4 is 100mm, except for the XS version, which gets an 80mm fork. That’s low by today’s standards, but it’s enough for the type of riding the bike was designed to do.

Drivetrain

The drivetrain is everything that transmits power from the pedals to the rear wheel. This includes the crank, the chain, the front and rear gear sprockets, the front and rear derailleurs that move the chain from one gear to the next, and the handlebar-mounted shifters that control the derailleurs.

The Marlin 4 carries a 3×7 drivetrain: there are three gears in the front and 7 in the rear. The gear range is not exceptionally wide and could be a problem if you will spend a lot of time riding steep hills.

The drivetrain components on the Marlin 4 are selected from Shimano’s entry-level Tourney and Altus lines. These are the lowest-priced components that Shimano makes, but that doesn’t mean they won’t work. Shimano makes some of the best drivetrain parts in the world. That experience filters down to even their cheapest products.Be aware that it will not be easy to upgrade the drivetrain components. 7×3 components are generally not compatible with components with other gear combinations, and most higher-end components will not be available in the 7×3 configuration. You would have to upgrade the entire drivetrain at the same time, and that would come at a significant price.

Brakes

The Marlin 4 carries mechanical disc brakes made by Tektro. These are basic, reliable brakes that will stop you effectively. Mechanical discs will stop you as effectively as the more expensive hydraulic discs, but they will not deliver the same comfort. Hydraulic brakes allow you to deliver more stopping power with less stress on your hands. That can be a real advantage if you ride down long hills: the hard squeeze required by mechanical discs can even lead to hand cramping and loss of control on long, steep hills. If you ride this kind of terrain you might be better served by a bike with hydraulic disc brakes. You can upgrade the mechanical disc brakes to hydraulics relatively easily.

Trek uses small brake levers with shorter reach for the XS and S sizes of the Marlin 4, which makes the levers easier for small hands to work.

Wheels

The Marlin 4 carries wheels and tires from Bontrager, an established manufacturer with a reputation for making quality products at accessible prices..Like many modern bikes, the Marlin 4 uses different wheel sizes for different bike sizes: the XS and Small sizes carry 27.5” wheels, the larger sizes use 29”.

The wheels come mounted with Bontrager XR2 Comp tires, which feature low-profile knobs suitable for crossover use between cement and low-intensity trail riding. The wheel-tire combination is on the heavy side, but it’s sturdy and serviceable and will do the job.

Other Components

Trek goes back to Bontrager to fill out the parts catalog, sourcing the saddle, seatpost, handlebar, and stem from the same manufacturer. That concentration probably provides more competitive component costs – big orders get better prices – and delivers solid, functional components. The Bontrager Blendr stem – the component that links the frame to the handlebars – is designed to allow easy mounting of accessories like lights, GPS, bike computers, or a GoPro or similar camera.

Component Roundup

The components that make up the Marlin 4 are all that you would expect – and in some cases a bit more – from an entry level bike from a premium manufacturer. Nothing is high end, but everything is functional and adequate. The components are intelligently selected and fit well together. You may find a bike with better spec in one component, but you will not find a better overall component mix on a bike in this price range.

Let’s rate the Marlin 4 component mix relative to other bikes in the sub-$700 range.

Component
Rating Out Of 5
Frame
4.5
Suspension
4
Drivetrain
3
Brakes
3.5
Wheels
4
Other
4

Features

How do all those components fit together, and what spices has Trek added to the overall recipe? Let’s take a look!

Sizing

Size is a key element in choosing a bicycle. Even a high end bike will not deliver the ride you want if it doesn’t fit you!

Trek produces the Marlin 4 in a wide variety of sizes: XS, S, M, L, XL and XXL. That means there’s a Marlin 4 to fit anyone from 4’6” to 6’8”! Use this chart to select your size:

If you fall between sizes, you may want to select the larger size if you plan to do mainly distance riding or the smaller size if you’ll be leaning toward trail riding. Better yet, find a dealer near you and try the two sizes out. The professionals at a good bike shop can help you choose the best size for you.

The Marlin 4 will accommodate riders up to 300 pounds.

Geometry

Bike geometry can be an intimidating subject, but there’s no need to go into detail. “Steep” or traditional geometry places the rider immediately above the pedals for optimum power transfer and the front wheel almost under the handlebar for optimum control. “Slack” or “modern” geometry may keep the steep saddle position, but rakes the fork forward and places the front wheel ahead of the rider for stability on steep descents.

The Marlin 4 falls in the traditional category, with a relatively steep head tube angle of 69.3 (XS and S) or 69.5 degrees. That’s a good choice for rolling trails and riding around town, but you will have to drop the seat and keep your weight well back to avoid going over the bars on steep descents. If you plan to ride the steep stuff on a regular basis a bike with slacker angles (but likely a steeper price) might serve better.

Special Additions

You might not expect to find extras on a sub-$500 bike, but Trek has tossed a few surprises into the mix.

  • Trek designed the Marlin 4 to be a town/trail crossover, so they’ve provided a kickstand mount.
  • The Marlin 4 comes ready to mount with a luggage rack, ideal for anything from bikepacking to carrying school books or groceries, another feature underscoring the multipurpose intent of the bike.
  • The XS and S sizes come with short-reach brake levers, smaller wheels, and a curved top tube for lower standover height. There is no “women-specific” version, but the XS and S sizes incorporate many features often found on women-specific bikes.
  • The Bontrager Blendr Stem easily mounts multiple accessories.
  • Internal cable routing protects cables, prevents snags, and keeps the bike looking clean and uncluttered.

That’s an unusual package to find on a bike at this price point, and it makes the Marlin 4 a leading candidate in the entry level trail/town hybrid market.

Performance

The ride is where it all comes together. The Marlin 4 handles as you would expect it to given its components, geometry, and purpose. To veteran cyclists like myself, it feels familiar, a throwback to the time when we all rode steep-angled hardtails with short-travel forks. Some things have changed, of course. Today’s entry-level shifting is infinitely better to what we had in those days! The low-end Shimano shifters and derailleurs on the Marlin 4 may not be as light, smooth or sophisticated as very expensive high end drivetrains, but they are surprisingly precise and require very little effort. They will do the job and do it well. The 29” wheels hold momentum far better than our old 26”-wheeled bikes, and they roll easily over obstacles, a significant improvement.

One limitation of the 3×7 drivetrain is the lack of very low gears for steep or extended climbs or for long flat-country rides where you want to preserve momentum. Given the purpose of the bike, those are minor limitations. Most people who buy an inexpensive town/trail hybrid will not be placing those demands on it!

The Marlin 4 does well on the entry-level trails it was designed to handle. The fork will handle the chatter of gravel riding or occasional roots and rocks, and the lack of rear suspension will help novice riders learn to stand on the pedals and use their legs to absorb shocks. Hardtails are great for novice trail riders because they help you learn to choose lines and to adjust your weight and body position rather than relying on suspension. The bike’s steep geometry is not designed for steep descents, but if you drop the seat and move your weight back you can roll some surprisingly steep terrain. Jumps and drops are not recommended!

The Marlin 4 also brings quality to the town side of its intended use. The upright position and relatively wide handlebars bring an immediate security and controllability that will appeal to novice riders. The luggage rack capacity makes this a great option for utility transport, and it’s tough enough to hop some curbs or plow through broken pavement if you feel like taking some bumps.

If you order your bike online or buy from anything but a good bike shop, take your bike to a qualified bike mechanic for fine tuning before you ride it. As with many entry level bikes, customer reviews of the Marlin 4 often refer to problems and complaints that come from the assembly and setup of the bike. Bikes are delivered partially assembled in boxes, and final assembly and tuning needs to be done by a qualified mechanic. No bike will perform well if it’s not put together and tuned properly.

The Bottom Line

Like any entry-level bike, the Trek Marlin 4 has to be evaluated according to its purpose. It’s not a featherweight cross-country race machine or a jump-ready enduro bike. If you’re looking for that kind of performance you’ll need to spend a lot more to get the bike you want.

The Marlin 4 is designed to serve budget-conscious riders as a cross country/light trail bike and as general around-town transportation. If that’s what you’re looking for and you want to get a solid, credible bicycle for the lowest possible price, it’s one of the best options available. You can get many better bikes, but you’ll spend a lot more. You can get cheaper bikes, but the quality is likely to be much lower.

Trek deserves some credit for their approach to the Marlin 4. They set out to design a highly functional bike for a specific purpose at the most accessible price point they could manage, and they’ve obviously put some effort into coming up with a package that provides real value. Its not a high-end mountain bike, but it isn’t meant to be. It’s an affordable and very useful bicycle, and if you’re looking for a bike in this niche for under $500, it is definitely one to consider.

Again, let’s rate the Marlin 4’s overall quality relative to other bikes in the sub-$700 range.

Review Category
Rating Out Of 5
Components
3.5
Build Quality
4
Ride Quality
4
Overall Value for Money
5