The battle for the best enduro suspension fork is hotting up. Muscled up forks with bigger and burlier chassis have entered the arena, throwing down the gauntlet to the skinnier forebears. We put 9 of the best 170 mm suspension forks to the test to find out which comes out on top.

The best mountain bike fork 2021 – We put 9 of the best 170 mm suspension forks to the test to find out which comes out on top!

For the last 2 years, it’s fair to say that not a lot has happened on the mainstream suspension fork scene. Yes, there have been small revisions to some of the leading forks, but there has been nothing groundbreaking. This year, instead of small evolutionary steps, some brands have taken a giant leap. Of course, we mean the two suspension giants FOX and RockShox who have both released their new 38 mm platforms to complement their existing 35 and 36 mm enduro offerings. Alongside the new Manitou Mezzer PRO, these bigger and burlier forks have made us ask whether stiffer forks are better. Will a stiffer fork make us faster or give us more control? To find out, we tested these burlier forks alongside the best 35 and 36 mm options in our group test, abusing them mercilessly on some gnarly Scottish terrain.

Table of contents


Suspension fork FAQ

What is a mountain bike suspension fork?

While containing many complex components, a suspension fork has a simple function. To lessen the impact of trail obstacles by absorbing their energy through its compression. The suspension fork has three main elements:

Damper – The damper’s function is to convert the kinetic energy of the spring into heat energy, usually by forcing oil through adjustable ports. The damper helps control the speed at which the suspension can compress and extend. The damper is found in the opposite fork leg to the spring.

Spring – The spring absorbs the energy created by an impact, isolating the rider from it. The spring stores the energy, releasing it when the fork extends, while the damper converts excess energy to heat. The stiffness of a spring is defined by its spring rate, the ratio of force per distance the spring is compressed. The spring is found in the opposite fork leg to the damper.

Chassis – The chassis of the fork houses the spring and damper, providing a strong and stable platform for the internals to work effectively and providing accurate steering for the rider.

What is the difference between coil and air springs in a suspension fork?

The spring component of the fork can be either an air spring or a coil spring. Coil springs are linear, meaning that the amount the coil compresses under a given load is identical no matter where the spring is in its travel. Some manufacturers now make progressive-rate springs with varying coil spacing, requiring more force to compress the spring the same distance at the end of the stroke than at the beginning. By far the most popular choice, most mountain bikes now come fitted with air sprung forks. An air spring is a sealed chamber filled with air. Under compression, the fork lowers push an internal air piston up against the air in the chamber, reducing its volume and increasing the pressure. This increase in pressure applies an opposing force to the air piston, pushing it back out again. Unlike coil springs, air springs have a progressive spring curve, the amount of force required to compress the spring increases exponentially through the stroke. The advantage of air springs is that their spring rate is defined by the air pressure in the air chamber, therefore they are easily adjusted by the user using a simple pump.

What does a negative spring do in my suspension fork?

Before your fork can start moving in response to an impact, it needs to reach the breakaway force. The breakaway force is the sum of the forces of the static friction of the seals and the pressure in the positive air chamber against the air piston. To reduce the breakaway force, either pressurised air or a coil spring can be added behind the piston to oppose the main air chamber spring and counterbalance the breakaway force. This is known as a negative spring. Most air negative air-springs use a valve or bypass dimple to equalise the pressure in the negative and positive spring, so the initial pressure on either side of the air piston is the same.

What does the damper do in my suspension fork?

The force of an impact transmits energy into the suspension, with the spring storing and returning energy by compressing and extending, while the damper stops the spring from bouncing uncontrollably or oscillating, controlling the rate at which it moves. Like the air spring, the damper is a chamber containing a piston that can move up and down, actuated by the movement of the suspension. Unlike the air spring, the chamber is filled with damping fluid, usually some kind of oil. When the damper is compressed, the volume of the immersing shaft displacing some of that oil, forcing it through the adjustable orifices of the compression damper – located at the top. When the fork extends again, the shaft is pulled in the other direction. The head of the shaft houses both the piston and the rebound damping. As the shaft extends, oil is forced from one side of the piston to the other, moving through the adjustable orifices of the rebound damping circuit. As the fluid flows, friction is generated, converting the energy stored in the suspension to heat. The tighter the restriction, i.e. the smaller the opening of adjustable orifices/valving, the more energy is converted as the oil flows through the damper, and in turn, the higher the damping.

What is rebound damping?

Rebound damping controls the speed at which compressed suspension extends after an impact. If rebound damping is too low (-) the suspension will extend too fast and feel bouncy and out of control. If the rebound damping is too high (+) the suspension will not recover fast enough after repeated impacts and pack down, sinking ever lower into its travel and performing poorly.

What is low-speed compression damping?

Low-speed compression damping influences your suspension characteristics at low shaft speeds (not bike speeds), predominantly influencing the mid-portion of the suspension travel. If you feel like you have achieved a good spring rate with good small bump performance and good bottom-out control but you feel that the bike lacks mid-stroke support, sinking deep into its travel when you brake hard, ride steep trails or push the bike into corners and jump faces, you need to add more low-speed compression damping. Adding low-speed compression damping does decrease suspension sensitivity, so you only want to add the minimum level to achieve enough support.

What is high-speed compression damping?

The most expensive forks and rear shocks have a high-speed compression damping adjustment (HSC), controlling the damping when the suspension compresses at high shaft speeds (big, fast impacts). If you find that your fork or shock is still bottoming out too easily and have a high-end shock and fork with the option, you can adjust your high-speed compression damping. Adding more high-speed compression damping reduces the amount of travel the fork uses in high-speed impacts (shaft speed not bike speed). Low levels of high-speed compression result in digressive damping which allows full travel easily in response to big, fast hits.

When I set up my fork, should I measure the adjustments from fully closed or fully open?

You should always measure the number of ‘clicks’ of your fork settings from fully closed (maximum damping). This gives a better reference point, as when fully opening the ports inside your suspension, the last click or so tends to be a little vague due to different tolerances from fork to fork.

How should I set up my suspension fork sag?

Sag is important when setting up your suspension fork. Sag is the amount your fork compresses under the rider weight (including riding gear) and setting the correct sag is the only way of reaching the optimum air pressure for your riding weight and style. Most fork manufacturers recommend between 15-20% sag depending on riding style. Sag can also be considered a tuning method. Changing the amount of sag on the forks changes the geometry of your bike, running less sag will cause the front of the bike to stay high on steep trails and under braking but will result in a harsher ride with less cornering traction. Running more sag will give a more comfortable ride with more grip, but lower the front end height under hard braking and on steep trails. It’s all a balance. In general, more sag (20%) is better for cornering, increasing weight on the front wheel and helping the front end dive through turns, while less sag (15%) is better for high-speed stability and pedalling efficiency.

How often should I service my suspension fork?

Let’s face it, nobody likes spending money on servicing. Instead, we would love to spend all our expendable cash on shiny new bike kit. However, you wouldn’t buy a Ferrari 488 and never change the oil. Suspension forks are complex moving parts and therefore require frequent lubrication. Investing time keeping your fork well serviced will give you a noticeable performance benefit. All the forks in this test use suspension oil in the lowers to lubricate the seals and while a full damper service may be beyond the capabilities of most amateur mechanics, a lower leg service is a very straightforward process. Most fork brands produce service schedules and useful how-to videos and tutorials and learning how to do a basic service is a treat for you and your bike. Changing oil regularly will not only boost your mechanical kung-fu but also leave you with silky smooth forks.

What do I do if my suspension fork creaks?

Creaking forks are unnerving and nearly all manufacturers suffer from this with a very small proportion of their forks. Telltale symptoms include sharp cracking or popping sounds under braking or full compression. The issue may sometimes be down to dirt or grime under the crown race, but is more often the stanchions creaking in the press fit crown. Both RockShox and FOX are the biggest offenders, not because their forks necessarily creak more than others but because their forks are far more popular, and therefore rare problems are seen in larger numbers. If your fork creaks under hard braking, the first step is to check and clean the crown race and headset bearing faces. If, after that, your fork still creaks then it’s time to call in the professionals and drop off your fork at a service centre. Many manufacturers will replace the CSU (crown, steerer and stanchion assembly) under warranty.

Can I adjust my mountain bike suspension fork travel?

If you frequently buy new frames or like to adjust the geometry of your bike, then a fork with adjustable travel may be desirable. While there used to be on-trail travel adjust systems a few years ago, such systems tended to compromise performance. The current range of top-tier enduro forks are fixed travel. However, some of the forks like the Manitou Mezzer Pro have internally adjustable travel, allowing you to change the travel up to 50 mm using internal travel reducers. This does require partial disassembly of the fork but allows a lot of flexibility and takes the worry out of experimenting with a travel change. The travel of the other forks can be adjusted but in most cases, a different length air spring will need to be purchased.

Why do we not have upside-down suspension forks like motorbikes?

We have been waiting for a good upside-down suspension fork for years. Once motorbikes went upside-down they never looked back. so why don’t we have an inverted fork? Inverted forks make a lot of sense, as you hammer down the trail, the highest fore-aft stress your forks encounter is under the crown where the leverage is highest. On a standard fork, this is where the stanchions are bonded into the crown. On an upside fork, this point can be substantially thicker using more material, resulting in more fore-aft stiffness. However, having no arch means that upside-down forks have always suffered from increased lateral flex. We’ve tested a number of upside-down forks over the years and have found that while they offer many advantages in ride comfort, they still lack the precise steering in high-load situations that aggressive riders require and often come at a price premium. We did invite an upside-down fork to this test but it was declined as it was deemed that our findings would be the same.

Clash of the titans. The new RockShox ZEB and FOX 38 have taken chassis stiffness to new levels. Is this the new yardstick for enduro performance or is it more than we need?

What makes a great suspension fork?

While unquestionably complex, a suspension fork has three main components. Firstly, it has a spring to absorb the violent hits when you roll foolishly into a crazy line. Secondly, the fork contains an oil-filled damper, which controls the speed of the spring. By forcing oil through small ports it converts the kinetic energy of the spring into heat. The best dampers will provide support and stability on steep terrain, keeping the fork high in its travel under hard braking and weight shifts, and using full travel only when needed. Finally, the fork needs a stiff chassis, allowing steering inputs from the bars to be translated accurately onto the trail, carving accurate lines while under pressure and keeping you out of the trees. Often, with infinite tuning configurations, the best forks will be easy to set up to your riding style and home trails without needing a PhD in suspension kinematics.

Hmm, we’re not sure a finger should bend that way. We do the hard work so you don’t have to. Stuart picked up some new metalwork in his hand after a brutal high-speed high-side.
The IRT chamber in the Manitou Mezzer PRO allows you to tune the mid to end stroke, without compromising small bump sensitivity.
The O.T.T adjuster on the DVO Onyx SC D1 increases or decreases the spring preload on the negative spring, allowing you to tune its initial sensitivity.
An accurate shock pump is vital if you have a low-pressure fork like the Manitou Mezzer PRO. When you have only 50 psi in the main chamber, 2–3 psi make a considerable difference.

How to choose the right suspension fork for your bike

When it comes to choosing the best suspension fork for your bike, there are several points you need to consider.

Wheel size
The first consideration is the wheel size. Yes, you can physically fit a 27.5” wheel into a 29” fork, but the axle to crown distance (if you buy a fork with the same travel) will be different on the longer 29” fork, changing the geometry of your bike.

Travel
Unless you know what you are doing or are looking to change the personality of your bike, it is best to stick to the amount of travel the bike comes with from the factory. Fitting a longer travel fork will raise both the stack height and bottom bracket height of your bike, impacting the handling. Also, fitting a longer travel fork may void your bike’s warranty.

Air or coil?
There has been something of a resurgence of coil forks and shocks in the enduro sector. Finally, riders are realising that overall bike weight is less important than performance, allowing them to choose products that help their riding, not the readout on a scale. Requiring fewer seals, and therefore having less friction, coil spring forks have always been the champion of small bump compliance, smoothing the trail and providing huge grip. Air forks are certainly the most popular choice and while arguably they still cannot match a coil for sensitivity (though they are now very close), they are significantly lighter and can be easily adjusted to different rider weights where a coil fork might require a different spring to be installed. Generally, due to the nature of air compressing inside the spring, air forks have more progression, giving more support to the middle and end of the stroke. However, many of the latest coil forks feature technologies to increase end stroke support, such as the mechanical Ramp Control in the MRP or the trapped air volumes in the Marzocchi Bomber Z1 coil.

Coil forks will suit riders who want maximum grip and minimal servicing and don’t mind carrying a little extra weight.

Which offset is best?

The concept is simple: the shorter the fork offset, the longer the trail (the horizontal distance between where the wheel and the steering axis contact the ground). In theory, longer trail stabilises the steering and traditionally, manufacturers gave 29ers longer offsets to produce shorter trails for faster steering. However, that thinking is changing now that we are riding big wheels in harder terrain. Many brands are now offering multiple offsets per wheel size, such as the RockShox Lyrik Ultimate that offers both 51 and 42 mm offsets in 29” (46 and 37 mm in 27.5”). After extensive back-to-back testing with both offsets, we found that any differences in ride feel are very small and quickly counteracted by the rider’s position. We tend to choose the shorter offsets for our own bikes as there seems to be no loss of agility or responsiveness to the steering.

How much difference does 2 mm more stanchion diameter make?

Chassis stiffness – is bigger always better?

The diameter of the stanchions of a suspension fork often dictates its intended use. Forks with bigger stanchions are heavier and stiffer, thus most often used with longer travel for more gravity focussed use.

The new, bigger 38 mm stanchions are hot property in the enduro fork world right now and are claimed to be significantly stronger and stiffer. It might seem like a lot of excitement over a 2 mm increase. However, given the same wall thickness, doubling the diameter of a tube increases the tube stiffness four times, meaning that small changes in diameter play a bigger role than you may think. That said, there’s always a sweet spot as increasing the diameter of a tube often increases the weight. Also, we need to start asking when a fork is too stiff. Just like overly stiff carbon wheels that reduce grip in certain situations, compliance is important in forks too.

If you race, are a very heavy rider or push hard enough to flex a FOX 36 or RockShox Lyrik, then the latest generation of super forks will be ideal for you. However, if you are looking for more of an all-round bike for fun laps with friends and post-work shreds, the lighter and more comfortable 36/35 mm chassis may be the best choice. It’s ‘mountain bike rider nature’ to lust after the latest models and flagship products, but by being honest with yourself about how and where you ride, you will end up with a more balanced bike that best suits the riding you do.

How should I set up my suspension fork?

There are no longer good and bad forks, only good and great forks. Now, more than ever, the correct setup is key. If you want to find out more about how to get the most out of your bike, check out our complete guide to suspension fork setup. You can have the incredible RockShox Lyrik Ultimate but if you set it up badly, it will perform worse than a well set up RockShox Yari RC. Unlike shocks, where frame engineers use the rear suspension kinematics to control the forces acting on the shock, suspension forks all encounter the same leverage ratio: 1:1. Different riders with different riding styles may want different responses from their suspension fork. Some desire buttery smooth small bump compliance, some want huge support for big jumps and high speeds, some just want an easy-going touring setup. Manufacturers now have to balance the needs of those who want a good setup from the box, with those who love tinkering and agonise over one click of compression damping. Tuning focussed brands like DVO, FOX and Manitou allow almost every aspect of the suspension performance to be modified to suit the rider’s preferences, while Marzocchi, Ӧhlins and RockShox try to keep setup simple.

It is important to set your fork up properly. Some of the forks like the Manitou Mezzer use low pressures in the main spring, so small changes in pressure have a large impact. Some forks have some unique quirks but the basics are always the same. Check out our suspension fork setup guide and learn more about the magic inside a fork.

The contenders – Which forks did we include in this group test?

What a lineup! €10,246 of the finest suspension products on the market.

The aim of this test was to find the ultimate enduro fork – the fork that delivers the highest performance on everything from fast and loose natural singletrack to full-bore shit-yourself downhill tracks. Dual crown forks were out, as were skinny and flexible trail forks that put too much emphasis on reducing weight. We tested each fork at 170 mm (except for the FOX 36 which was tested at 160 mm due to its new position in the FOX lineup) and in the 29er wheel size. Both FOX and RockShox have huge lineups so we tested both their 36 and Lyrik platforms, as well as the bigger 38 and ZEB big-hitters. The Manitou Mezzer PRO and Öhlins RXF 36 M2 Air had to be included as both use three air chambers for extreme tunability. We wanted some coil options too – for riders who want minimal maintenance and easy setup, coil makes a lot of sense. The MRP Ribbon Coil stood out with it’s Ramp Control feature allowing the end-stroke progression to be adjusted and we had heard great things about the Marzocchi Bomber Z1 Coil. Rounding out the 9 fork test field was the DVO Onyx SC D1 as a tuner’s favourite, giving great control over every aspect of the fork.

Fork Travel Options Weight Price
DVO Onyx SC D1 160–180 mm 2.34 kg € 1,051
FOX 36 2021 Grip2 Factory 150, 160 mm 2.18 kg € 1,459
FOX 38 2021 Grip2 Factory 160, 170, 180 mm 2.32 kg € 1,589
Manitou Mezzer PRO 160, 170, 180 mm 2.10 kg € 1,050
Marzocchi Bomber Z1 Coil 170, 180 mm 2.61 kg € 840
MRP Ribbon Coil 140, 150, 160 mm 2.24 kg € 940
Öhlins RXF36 M2 Air 120, 140, 150 , 160 , 170 mm 2.14 kg € 1,189
RockShox Lyrik Ultimate 2021 150, 160, 170, 180 mm 2.06 k € 1,039
RockShox ZEB Ultimate 150, 160, 170, 180, 190 mm 2.32 kg € 1,089

Where is the Formula Selva, Intend Edge, EXT ERA and the burlier Öhlins?

There are some notable omissions in this group test with EXT, Formula and Intend missing, though all were invited to participate. EXT were keen to meet their pre-orders before sending a fork, but we have one coming and will update the review as soon as we have given it a hammering. Formula did not think that their Selva R fitted well with the latest 38 mm chassis forks and declined the offer – perhaps they are working on something new? We were keen to get a new Intend upside-down fork into the test but owner Cornelius indicated that our findings would be similar to the last fork we tested and declined our offer. By the time we headed into our back to back test session, the burlier RXF38 offering from Öhlins was still a well kept Swedish secret. However, we are very excited to put the stiffer chassis Öhlins head to head against the competition soon.

How we tested the suspension forks

While undeniably fun, it’s not an easy job testing suspension forks. With infinitely variable air springs, bottomless tokens and 4-way adjustable dampers, the possible configurations of each fork are almost limitless and that’s before even thinking about custom tuning. A well set up average fork will easily outperform a poorly setup exceptional fork, so it’s important to ensure each fork is dialled in before testing. We were interested to see how much time you allocate to fork setup and so we reached out over Instagram. Given the choice between “Less than one hour” or “More than one hour” over 650 of you responded and the responses were split 50/50. That means for every one of you that likes to incrementally tweak the low-speed compression adjuster each and every ride, there’s someone else who sets their fork once in the car park and never looks at it again.

Forks were swapped between sessions. Cheers to our mate Tom Corfield at The Bike God for the mechanical support.
We ran each fork for a considerable period after testing, to assess the durability and ease of service.
If the spring was compatible with tokens, we experimented to see how additional tokens modified the curve.
Sag was measured at the brands suggested pressure recommendations. We found most were in the 15-20% range.

Many brands are working hard to make their suspension forks easier to set up. Nearly all the models in this group test now feature recommended pressure stickers on the fork legs and some have interactive tuning apps to help the rider get a good starting point. The brand who is doing the best is certainly RockShox. Not only do they offer their TrailHead app, walking you through suspension setup but the ZEB and Lyrik both have sag markings on the stanchions, letting you quickly establish if you have the correct air pressure in the fork.

Simple and effective. Easier to use than remote timing, we used bar-mounted stopwatches to record timing data on the DH tracks, letting us see if certain forks allowed us to ride faster.

How did we test?

During the back to back sessions, we first set the fork using the manufacturer’s recommended setting for a given rider weight (fully kitted). Sag was recorded and recommended compression settings were used if given by the manufacturer. Several shuttle runs were performed to assess the manufacturer recommended setup before the test riders were free to tune the forks to their own preference. Forks were swapped during the midday break to ensure a reference point while experiences were still fresh. Runs were timed to be able to compare forks further and the testers rode at a speed where they were fast, but not out of control.

Adrenalin Uplift took the pedalling strain for us, letting us maximise the descents.

Where did we test?

There’s no place like home, especially when your UK office is based in the Tweed Valley, Scotland. With world-class, shuttle accessed DH and enduro trails right on the doorstep, we decided to keep the test close to home, on tracks that we had ridden thousands of times. Using the Adrenalin Uplift shuttle for support, we established two test tracks: the first a derivative of the legendary iXS downhill track with high-speed root gardens, eyeball popping turns and some fair-sized step-downs. The second took us from the doubles of Make or Brake into the fiercely washed out and hammered turns of Gold Run. Both tracks were just over 3 minutes of flat-out descending and each of the test riders knew every inside line and compression.

Riding the forks back to back quickly revealed the team favourites – the forks that let us ride harder and faster in total confidence.
“I’m going to catch you!” We weren’t racing, honest.
Hard on the brakes into the corner, the latest generation of forks have much more control through the stroke.
This is where you need a predictable fork. When grip is low, you need to trust that the fork will find every last morsel of traction.

The test team

Everyone’s thoughts on suspension and setup are different, so it was important that we had a large test team to put the forks through their paces.

Trev Worsey, 80 kg: Editor and test rider
“When it comes to suspension there are a few things I look for. I tend to prefer very steep and very loose trails so I need a fork that can balance really supportive mid-stroke performance while being super sensitive off the top for maximum grip and control.”
Finlay Anderson, 74 kg: Editor, photographer and test rider
“I am looking to progress my riding this year. Bigger jumps, bigger drops and faster speeds. As such, I need a fork that can handle the big hits and bigger cases, and will not need a lot of servicing.”
Stuart Wilcox, 73 kg: Ex-pro EWS racer, fast as f$ck
“I don’t spend as much time on the bike as I used to but I still like to ride full gas. I am looking for high-speed chassis stability and damper support. It’s also important that the fork is easy to set up as I prefer to ride rather than test these days.” Editor’s Note: Stu went down hard before we could shoot his profile photo, so here he is rocking the bullet. Get well soon Stu.
Tom Corfield, 95 kg: Pro bike mechanic.
“At 95kg, I am looking for maximum chassis support. I am especially interested in the new FOX 38 and ZEB platforms as I find I feel fork flex more than the little guys in this test.”
Alex Balfour, 84 kg: Mountain bike guide and coach.
“I like to spend my summers smashing out top to bottom runs on alpine singletrack. I look for all-round suspension performance with great grip and support. Reliability and durability are also very important to me as my bike has to survive long seasons of abuse.”
You can’t beat local trails for testing. Our test riders already had hundreds of laps of the two test tracks under their belt.
After each lap we made notes on support and grip, where we could push hard and where we were reaching for the brakes.
On smooth sections of trail, it’s all about mid-stroke support and not blowing through the travel on jump faces and landings.
Who doesn’t love a cheeky road gap?

Four things we learned from the 2021 fork test

We didn’t ride any faster on the bigger 38 mm platforms

Looking at the timing data, switching from a FOX 36 to FOX 38 or Lyrik Ultimate to a ZEB Ultimate did not result in an observable increase in speed. While we picked terrain that should have favoured a bigger fork, our 75–90 kg riders were just as fast on the (relatively) smaller platforms. We did find the big FOX 38 was more sensitive and offered slightly more grip, but it didn’t take chunks out of the stopwatch. Admittedly, we weren’t riding at race pace but were riding at the fastest speed the bike allowed without risk of crashing – the kind of speed you run when hunting down your mates on a trail. Racers may be able to exploit the stiffer chassis when riding right on the limit to save a few seconds here and there but if your riding is more mid-pack, upgrading to a 38 mm chassis will not put you on top of the podium.

While undoubtedly fast, on enduro terrain we did not ride significantly faster using the new 37 and 38mm forks when compared to the best of the 35 and 36 mm forks.

Some forks take a lot longer to set up

To get the best out of their product, suspension designers need to make it easy for us. When you jump into a car, you don’t need a manual to work out how to make it warmer inside. It should be the same with suspension forks. RockShox is ahead of the curve here and both their Lyrik and ZEB platforms can be set up in 10 minutes with a wide sweet-spot. The Manitou Mezzer is the toughest fork to get right, with its low pressures and very sensitive IRT chamber, it is one for those who enjoy taking time to dial in their settings.

The Manitou Mezzer PRO’s IRT is a great way of adjusting the fork feel. However, it has a very strong impact on the fork’s performance and takes time to dial in.

Coil still has its place

The Marzocchi Bomber Z1 was a highlight in this group test. Yes, it is basic. Yes, you need to find the spring rate that works for you. And yes, it’s a heavy beast. But once you find the correct spring, the top-tier performance let us keep up with the big boys effortlessly. Surprisingly progressive and supportive, it’s the standout bargain in this group test if you can swallow the additional weight. However, putting a coil inside a fork does not automatically make it great and it needs to be balanced with a supportive chassis. The MRP Ribbon Coil frustrated us with its vague chassis, holding us back on the descents.

We were not expecting to like the Marzocchi Bomber Z1 as much as we did. It’s a superb fork for the money if you can accept the additional weight.

Whatever happened to 20 mm axles?

With most manufacturers now focussing their marketing on chassis support and accurate steering, it feels as though we missed an opportunity with 20 mm axles. With the new 38 mm platforms now offering 190 mm of travel, 15 mm is now the universal standard for single-crown fork axles and the stiffer and stronger 20 mm thru-axle format has almost been eradicated from the enduro sector. Going against common sense, no forks in this test have a 20 mm option. For 2021, when it comes to enduro forks, the 20 mm thru-axle is dead.

Did we give up on 20 mm axles too soon? Stiffer and stronger, they would have made a lot of sense for the latest RockShox ZEB and FOX 38 mm platforms.

Which is the best enduro fork of 2021?

What a battle of the titans it was! With testing over, we were left with crashes, broken bones, countless impacts and a whole lot of hollering. Overall, the standard of forks in the test was very impressive – never before has going so fast been so effortlessly easy.

Starting with our least favourite fork, the MRP Ribbon coil struggled to keep up through rock gardens and over big hits, feeling over-active in the middle of the travel with a flexible chassis. Compared to the best of the competition, we were braking sooner and less confident pushing the limit. There was nothing trail about the Ӧhlins RXF M2, which is a great upgrade over the outgoing model. The Ramp Up chamber offers easier adjustment of the spring rate than swapping out tokens, allowing you to quickly find a setup that works for you. Compared to the best in test, the fork lacks the buttery small bump compliance, though the heavier damping feels better the faster you go. The DVO Onyx SC D1 is a real tuner’s dream. Using the O.T.T adjustment we were highly impressed with the fork’s ability to track the ground like a coil. Under hard and fast repetitive hits, the Onyx makes swift progress but it is a heavy beast. If you really don’t care about your suspension setup and just want a fork that works, then buy a Marzocchi Bomber Z1 Coil. It’s effortless to set up and boasts performance that defies its affordable price tag. It really is the hidden gem in this lineup but is not one for weight weenies, adding a lot of weight to the bike. The FOX 36 2021 has seen some good updates too. Downgraded to an all-mountain fork, we didn’t feel that it held us back on full-gas DH trails. When ridden back-to-back against the RockShox Lyrik 2021, we found we could find a good setup quicker on the Lyrik and it stayed higher in the travel, maintaining the bike’s geometry better while still absorbing the big hits. The RockShox Lyrik won our group test last year and is still the fork to beat. The 2021 model boasts improved performance and is still great value, offering all you could need unless your riding style dictates a super stiff chassis. It takes our Best Buy award.

The battle of the big-hitters. Are the latest 37 and 38 mm chassis forks better, or has the arms race gone too far?

And then we come to the big hitters. If big-hit stability, rock gardens and sending it at every opportunity is part of your normal riding vocabulary, then you will undoubtedly be drawn to the bigger chassis forks. The Manitou Mezzer is an impressive performer but you will need patience and accurate adjustments to get the best out of it. A champion of mid-stroke support, the Mezzer handles steep trails with effortless composure but the heavy damping never quite delivered the silky-smooth ride we were hoping for. The RockShox ZEB Ultimate also requires accurate pressures to get the best out of it but it’s an easier fork to set up and with its high and supportive ride height, it’s the people’s champion. While not quite as easy to set up at the ZEB, once you have the FOX 38 Factory dialled in, it gives unrivalled small bump compliance without any sacrifice in mid-stroke support. The FOX 38 delivered no matter where we were in the travel and when the going got really tough, it was the fork we all wanted to run, meaning it took the Best in Test award.

BEST IN TEST FOX 38 GRIP2 Factory

FOX 38 GRIP2 FLOAT Factory | 2.32 kg | € 1,589 | ridefox.com

The new FOX 38 is more than just a beefed-up 36. Instead, it feels more like a mini 40 with sublime damping and support. Available in 170–180 mm travel, it’s the ideal complement to the latest hard-hitting, gravity-focussed 29er enduro rigs and eMTBs. Overall, for those looking to push their riding very hard in the bike park, the FOX 38 is the best performing enduro fork on the market we’ve tested, taking the Best In Test. Read the full review here.

Tops

  • amazing stiffness/performance balance
  • next level grip and support

Flops

  • one of our forks creaked
  • controls need more defined clicks

BEST BUY RockShox Lyrik Ultimate 2021

RockShox Lyrik Ultimate 2021 | 2.06 kg | € 1,039 | www.sram.com

The RockShox Lyrik RC2 took our Best in Test in 2018 and the latest Ultimate model is still the standard by which all other forks are measured. The FOX 38 and ZEB may be a better choice for heavy-duty bike park thrashers, but faced with a gnarly natural alpine trail, the Lyrik Ultimate really is all you will need. With sweet-spot performance and an amazing price, the Lyrik is still our top recommendation, taking our Best Buy award. Read the full review here.

Tops

  • superb sensitivity and performance
  • effortless setup

Flops

  • no QR axle

The rest

DVO ONYX SC D1

DVO Onyx SC D1 | 2.34 kg | € 1,051 | dvosuspension.com

The DVO Onyx is a potent performer, with a stiff chassis and its O.T.T control that allows you to fine-tune the sensitivity without compromising support. The fork feels very well made, and ridden back to back delivers a similar ride quality as the “best buy” RockShox Lyrik. However, it does come with a weight penalty. If you’re looking for something different and something you can tune extensively, then the DVO Onyx will not hold you back. Read the full review here.

Tops

  • excellent damping
  • O.T.T works really well

Flops

  • HSC is overkill and hard to use
  • coil weight despite the air-spring

FOX 36 2021 GRIP2 Factory

FOX 36 RC2 FLOAT Factory | 2.18 kg | € 1,459 | ridefox.com

On the trail, the FOX 36 Factory feels, well, like a FOX 36. It’s a fork at the very top of its game. The GRIP2 damper gives huge control over the rebound and compression circuits with both high- and low- speed adjustment and once dialled in, grip and support are exceptional. However, it is still a very expensive fork and the competition is hotting up. Read the full review here.

Tops

  • amazingly balanced performance
  • full control over the ride feel

Flops

  • expensive compared to the Lyrik
  • requires experience to set up correctly

Manitou Mezzer PRO

Manitou Mezzer PRO | 2.1 kg | € 1,050 | hayesbicycle.com

The Manitou Mezzer PRO takes a very different approach to set up and needs more attention to reach its optimum performance. Tuners, or those who are very particular about their setup will love the Manitou Mezzers as it offers almost unlimited control. We found we could dial in huge mid-stroke support without compromising the end of the travel, but we never managed to get the same small bump compliance as the leading forks in the test. Read the full review here.

Tops

  • infinite tuning options
  • great mid- and end-stroke control

Flops

  • more involved setup
  • sensitivity is good but not great

Marzocchi Bomber Z1 Coil

Marzocchi Bomber Z1 Coil | 2.61 kg | € 840 | marzocchi.com

If you are looking for quick setup, maximum grip, minimal maintenance and don’t care about weight, then you can stop reading now. The Marzocchi Bomber Z1 is the fork for you and will also save you a lump of cash. However, the fork is very heavy and adds a considerable amount of weight to the bike. If you fall comfortably in the middle of the spring rate, the Z1 will likely deliver exceptional performance out of the box. Read the full review here.

Tops

  • very good small bump performance and sensitivity
  • more progressive than expected

Flops

  • heavy
  • performance will depend on suitable spring rate

MRP Ribbon Coil

MRP Ribbon Coil | 2.24 kg | € 940 | mrpbike.com

Overall, the MRP Ribbon Coil proved a comfortable and extremely sensitive trail fork. However, when pushed in rough terrain, more aggressive riders will find it too flexy and lacking in support. If you are looking for a burly enduro fork, we would look elsewhere. Read the full review here.

Tops

  • smooth small-bump performance
  • Ramp Control works to increase end-stroke control

Flops

  • chassis flex leads to unpredictability
  • linear feel and limited support

Öhlins RXF 36 M2 Air

Öhlins RXF 36 M2 Air | 2.14 kg | € 1,189 | ohlins.com

Though having additional air chambers to tune may sound complicated, in practice the Ӧhlins is very easy to set up and performs exceptionally well. Stiffer and higher-performing than the original RXF, the Öhlins RXF 36 M2 is a viable alternative to the big-hitters from FOX and RockShox. With a heavily damped tune, it will be a fork that feels best under heavy or more aggressive riders, getting better the faster you go. Read the full review here.

Tops

  • very tunable thanks to the Ramp chamber
  • excellent support and performance

Flops

  • heavy damping suits stronger riders
  • lacks small bump sensitivity

RockShox ZEB Ultimate

RockShox ZEB Ultimate 2021 | 2.32 kg | € 1,089 | sram.com

If a RockShox Lyrik isn’t burly enough for you, you will love the RockShox ZEB. The ZEB is super accurate, effortlessly easy to set up and delivers an aggressive price point. It’s a fork for those who measure air time in seconds, or who can push the O-ring to the top on corners. However, with minimal compliance, you need to ride hard to get the best from it. For most, the Lyrik will be the more rounded choice. Read the full review here.

Tops

  • easy to get a good setup
  • stiffest fork on test for crazy accuracy

Flops

  • you have to ride it hard
  • never really shines

More important articles for you to check out

In addition to this group test, we have a number of important suspension-related articles for you to check out. Here’s our ultimate guide to setting up your MTB suspension, our group test of the best shock pumps and how to prevent arm pump. Be sure to check them out!

All forks on test: DVO Onyx SC D1 | FOX 36 2021 Grip2 Factory | FOX 38 2021 Grip2 Factory | Manitou Mezzer PRO | Marzocchi Bomber Z1 Coil | MRP Ribbon Coil | Öhlins RXF36 M2 Air | RockShox Lyrik Ultimate 2021 | RockShox ZEB Ultimate

Words: Trev Worsey Photos: Finlay Anderson

About the author

Trev Worsey

Trevor loves adventure. Whisky, riding his bike and everything in between. Though he was born in England, he believes he should have been Scottish. Besides being accustomed to bad weather he's a specialist when it comes to steep and demanding trails. Once, he was in love with competition and raced in the early years of the EWS, but now, at 41-years-old, he no longer has anything to prove. Nonetheless, demonstrating that you can teach an old dog new tricks, he continues to hold his own against the wild and fearless youth. As a reminder of his new role as a father, the words “Think about Brook." (his son) are inscribed on his top tube as a gentle warning against unruly riding. Together with his young family and two crazy dogs, you will almost always find him outdoors. Whether it's teaching Brook to ride trails, hammering out gravel loops, surfing, skiing or canoeing, he’ll be there no matter the weather, like a true Scotsman.