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Trek Marlin 4 bike | A detailed guide

Marlin 4 is not a bike made to take a beating its a bike for laid back easy trail commuters who love to explore nature get some cardio exercise and generally just enjoy it’s not a bike for hardcore mountain bikers but a beginner could use it to try to get the feel of the sport and used this bike as a hybrid bike.

Marlin 4 is not a replaceable bike as it does not contain advanced features of hardtail and full-suspension mountain bikes, you have easy access to get one, their range is from 600$ to 700$, these are cheap bikes used for both road and cross country purposes. Marlin 4 is totally relatable with hybrid bikes in their structure, shape, tire, and frame type. their cheap price does affect their quality, these bikes can lift more than 100kg weight but the difference comes in their trails and the speed, you can use it for mountain biking purposes but in a limit and if your weight is more than 100kg then you have to limit your speed with this bike on hard, rocky and country trails, the main reason is that marlin 4 does not contain shocks below the saddle and their frame does not support much more speed.

What kind of trails in marlin 4 best for:

Light and medium trails are mostly recommended for trek marlin 4 but always avoid hard and straight down trails. take the speed of your bike in a limited range when you are landing straight downhill trails, you will feel a difference in comfort level when we compare marlin 4 with other mountain bikes(components of Marlin 4 are rigid and uncomfortable). for couples, marlin 4 would be the best option for road and cross-country trails it can be an awesome
bike for kids who are just starting to learn mountain biking or developing their interest in the sport.


Trek Marlin 4 is not made for speedy races, these are manufactured just for riding purposes and for those who are in their initial level of riding.

All the specs of Trek Marlin 4 are given in the table below:

Trek Marlin 4 Size27.529er
Frame MaterialAluminium
Fork 100mm
Front DerailerShimano 3 Speed
Rear DerailerShimano 7 Speed
Gears 21
Brakes Mechanical/ Cable disc brakes
Tire size 2.20
Weight 14KG30.82ibs
Number of tooth cassete14 by 28
Rotors 160mm
Frame Size 7 Sizes

Upgrading parts of Trek Marlin 4:

For a hundred-dollar bike, it is necessary to upgrade and change its components with new mountain bike parts, no matter how much you spend on Trek Marlin 4 but upgrading is important because a bike has cheap components which do not provide fantastic grip and these components are pedals, cable disc brakes, grips, and four bolts stem body. these are cheap services and you can easily afford and buy from any online store for your bike.

The most important upgrade is shifting from cable disc brakes to hydraulic disc brakes and it costs about nearly 100$.

If it has a tubing system then you can upgrade to a tubeless tire, but it totally depends on how much you ride and where you ride.

As Marlin 4 has less power capacity, if it’s bothering you on the hard trails then spend money on a drive train for your bike which will work smooth and better through any type of terrain.

If you are uncomfortable with the dropper post, then it is also a cheap investment to upgrade it to some better dropper of your own size with a high comfort zone.

If you have any friend who had an MTB bike in the past you can ask him for used tires for your bike, it’s not important but upgrading tires play a big role in providing grip on the trail and increases safety, its not necessary because according to experience it totally depends on the trails whether wet, muddy and sandy after that here comes the decision about tires.

Marlin 4 and Hybrid bikes, both have slick tires which are usually for road riding and commuting that’s why if you want off-road riding then surely you have to upgrade some good Maxxis company-branded tires.

Big upgrading in Marlin 4 is upgrading from aluminum frame to carbon frame but I am not recommending it for you because it depends on your budget and you have to decide for your bike in a limited budget range.

Size of Trek Marlin 4 according to riders Height:

We all have different heights which confuse riders when buying a new Trek Marlin 4 bike. the given table below gives data related to the heights of the riders in centimeters which makes it easier to choose the right size for you.

Frame Size Riders Height =

If it’s difficult then further I have collected data in inches.

Frame SizeRides Height=

Always buy your own size bike for yourself because higher or lower bike height will always cause disturbing you and it irritates you a lot, you will always feel discomfort ability in riding through terrains.

Trek Marlin 4 beginner guide:

Yes, its true Marlin 4 is an entry-level bike for those who are new in the biking world, it has the advantage it is best for road biking, especially for new riders, and an extra advantage of involving in the cross-country trails to learn fully about the hard trails, that’s why it is the best choice for the beginners.

Another main reason the experts avoid this bike is that it will limit your progress and you would not be able to learn and go forward if you have had this bike for many years.

It is mostly for beginners who have even do not tried biking in their life, age does not matter whether you are 20 years old or 60 years old, the main purpose of buying this bike is that you can learn from it honestly and peacefully in the beginning and when you leveled up this bike now for sure move on and upgrade it with some new expensive Bike.

Trek Marlin 4 frame:

The structure of the frame is simply designed and does not contain shocks, aluminium material is used in its manufacturing which is much more light in weight, and does not affect the speed of bikes in road riding. if you afford an upgrading frame of your bike then surely you will follow the hard and rocky trails of cross-country mountain biking.

The frame is firm and strong enough to hold the rider’s weight(80kg to 100kg) but it looks like it is an old model bike because the shape of the frame resembles that of old model bikes.

Cable routing of Trek Marlin 4:

Old model frames of Trek Marlin 4 have external brake routing where you have easy access to repair the brakes because the brake cables are visible outside and the frame does not contain any system of internal routing. but new models of Marlin 4 have internal cable routing of brakes within the frame.

Always remember if you are ordering Marlin 4 for yourself, check the cable routing system of your frame before buying from the online store.

The main difference between Trek Marlin 4 vs 5 is their cable routing, Marlin 4 has a cable routing system and Marlin 5 has a hydraulic brake system.

Marlin has cable disc brakes which are not better and have less working capacity as compared to the hydraulic disc brake system. Cable brakes cost cheaper in their repair as compared to hydraulic disc brakes.

Cable disc brakes have the advantage you can easily repair these brakes in your home with tools easily without spending bucks on the mechanic.

Trek Marlin 4 and long rides:

Marlin 4 is an unlucky bike when we discuss it for long rides, the reason is that it does not contain well air forks which would handle and absorbs bumps of the trails, it has spring forks which are limited edition and do not support long miles of hard and rough terrain.

Another reason is that Marlin 4 does not have enough power to climb up and follow the single trails of mountain biking, this is the main reason that the pro riders and experts avoid marlin 4 for racing and for long rides.

Is Trek Marlin 4 bike right for you?

It is the most confusing point well because of the rider’s experience in the mountain biking world so that how much you are using your bike for riding in your life. it totally depends on you and the downtown of your trails, if your house is in the valley and downtown and you have to come to the country daily for work purposes then also it is good and will not expire so early.

Marlin 4 is basically used for road rides and straightways without any jumps.

Is the trek Marlin 4 bike the right bike for jumps and drops?

Avoid big drops and big jumps when you are riding on a Marlin4 bike because the frame and forks do not support pop trails, skip trails with big drops and higher jumps otherwise your bike will crash and it will cause trouble in the drive trains, fork, and handlebar.

Smooth and straight trails are usually recommended for Marlin 4 because hybrid bikes and Marlin 4 bikes both have the same geometry and same function.

The handlebar of Trek Marlin 4 bike:

The handlebar is of aluminum metal and does not support long travel on hard terrains because Marlin 4 has a cheap bar made for light terrains and does not support aggressive terrains.

The bar has coil forks, upgrading from the coil to air forks would make Marlin 4 the right bike for aggressive trails.

Trek Marlin 4 sealed or open bearings?

Marlin 4 does not have sealed bearings that are open to the atmosphere and absorb dust and dirt, Its one of the cons of marlin 4 as well.

Difference between Trek Marlin 4 vs Marlin 5:

ComponentsTrek Marlin 4Trek Marlin 5
Frame AluminiumAlluminium
Wheel size 27.5 and 2929
Model 20202021
Bike Category Crosscountry Bike Cross country Bike
Weight 14.5kg 14.4kg
Fork Suntour XC E28Suntour XC E28
HandlebarAluminium Aluminium
WheelAluminium Aluminium
Brake Type Mechanical Cable disc brake Hydraulic Disc Brake
Drive Train 3 by 7 3 by 7
Gear Travel Range 42 km/h49km/h
Front Travel 100mm 100mm
Dropper post Rigid Material Rigid Material
Company Name Trekbikes Trekbikes

Geometry difference between Marlin 4 vs Marlin 5 :

Geometry Components Trek Marlin 4 Trek Marlin 5
Stack 602 630
Reach 434480
Stack /Reach Ratio 1.39 1.31
Top Tube Length618673
Seat Tube Length 444559
Seat Tube Angle 73 73
Head Tube Length 90120
Head Tube Angle 69.5 69.5
BB Drop 58 58
Front Center 684741
BB Height 310311
Chainstay Length 438438
Wheelbase 11161173
Trail 93 93
Standover Height 758804


While this bike is certainly better than Walmart bikes but still not made for a beating it just lacks that kind of potential but it can be a great entry-level bike for mountain bikers who had like a hybrid kind of bike that can slowly get in their interest and its also great for kids as well all in all its the best cheap learning tool for mountain biking.