Manitou Mezzer Pro | Just The Right Amount Of Tuning?

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We put the Manitou Mezzer Pro fork through a winter of hard use – did the testers come back smiling?

There’s a particular place online where some bike mechanics share photos, and one of the perennial posts is bikes that have been built with the forks backwards. Occasionally though, someone will go “No, those are Manitous, they’re meant to be like that” – I didn’t have to tell anyone this while testing these forks, but I was prepared to, thanks to the fork arch going behind the stanchions.

Manitou does it this way because apparently the reverse arch lets them engineer a given amount of stiffness into the fork, for less weight.

Manitou Mezzer Pro
Nice decals!

Manitou Mezzer Pro Features and Setup

  • From: Hotlines
  • Price: £899.99
  • Weight: 2011g

The real headline with this single crown fork is the whopping 37mm stanchions (dialling it up to 11 in increments of 3.363mm).

They’ve still kept the weight around 2Kg, ours weighing just a touch over at 2011g, which is within 10g of the claimed weight of Rockshox’ Lyrik. Pretty impressive, given the stanchions and everything around them have the diameter increased by 2mm.

Manitou Mezzer Pro Fork
The back!
Manitou Mezzer Pro Fork
The front.

It has a slightly unusual bolt up axle: Manitou’s Hexlock SL2 (we have patents to thank for all the differences between manufacturers). It’s not tricky, but it is different. Rather than using an allen key to spin the axle itself in, the tool goes in the other fork leg, where it turns a threaded insert to pull the axle all the way home and tighten it.

The Manitou Mezzer Pro also comes with a bolt on mudguard, which is nice to see (some manufacturers put threaded holes in their fork arches, but don’t seem to have actually made the mudguard for them). In use, I found it more than big enough, extending well backwards and slightly further forward than those cheap, zip-tied ones tend to. With the mudguard, there’s tyre clearance for 2.6in rubber, and without, 2.8in.

On the fork you’ll find low and high speed compression settings, rebound, air spring… and a valve labelled IRT, which stands for “Infinite Rate Tune”. It’s basically an air chamber that takes the place of volume spacers in other forks and, naturally, using a valve and shock pump makes it much quicker that removing a top cap and bolting on chunks of plastic.

Manitou Mezzer Pro Fork
Infinite Rate Tune

The air spring is actually filled from the bottom of the left leg, which charges up not only the spring, but also a negative spring air chamber at the same time. The negative spring pulls down slightly on the upper legs, letting them overcome stiction and start moving a bit more easily.

The IRT is the valve at the top of the left leg, where you’d normally assume tha air spring is, but it is clearly labelled. Procedure is to fill the IRT first, then the air spring, both with recommended pressures on a chart.

Documentation was little a bit lacking during my review period. That said, I also had the backing of Hayes Group engineers and marketeers, some of whom I got to talk to with video calls. While those calls were very useful, presumably they’re not something on offer to their customers? Mostly, I just had the setup guide to work from, which is here. It’d be nice for some version of that chart to go on the back of the fork leg.

Manitou Mezzer Pro Fork
Nice decals, but we could use some instructions.

“PRESSURIZE IRT CHAMBER FIRST” is the last thing it says in the setup section, so this definitely isn’t written for the kind of people who are just going to jump in without reading everything carefully. It’s enough to go from though, and to start with I went with the recommended settings. That yielded a sag between 25% and 30%. I usually run around 30%, and reduce it for shorter travel forks; or the baked height of summer when I’m likely to be going faster.

At 170mm, these forks seemed unlikely to run out of travel quickly… I decided to try them as is, but left all the compression open for the first ride. They’re also available in 160mm or 180mm versions.

The Ride

It became immediately apparent on the first descent that this is an absolute bruiser of a fork. Supple, but solid as a rock and not prone to hanging on things or getting knocked off line. Even months into the test, when I was well used to it, during a particularly prolonged and choppy crash it struck me how solid the bike felt with the Manitou Mezzer Pro upfront (just before I separated from bike and pancaked into the bank of the stream bed I was riding down – not the fork’s fault).

Manitou Mezzer Pro Fork Nukeproof Mega
Tested on a Nukeproof Mega

I only ran this on a Nukeproof Mega, which I’d not ridden before, so there’s been work to do in terms of separating the character of fork and bike. Neither is subtle or delicate, and in those respects they’re a good match for each other. Both felt rock solid (in the good way!) down every descent, and both are definitely biased toward descending rather than big XC loops.

The Manitou Mezzer Pro compression damping is very much from the school of “tuning, not lockout”, and as with Cane Creek’s Helm, I ended up running low and high speed compression open most of the time, or with just a few clicks. As such, while it wasn’t terrible stood up on climbs, it was more suited to seated climbing than mashing out of the saddle. Bear this in mind before you whack that 36t chainring on.

Manitou Mezzer Pro Fork
Still going well after much mud

The negative spring makes them very smooth in the initial travel. Initially it seemed a shame it can’t be adjusted independently of the main air spring, but I found it plenty smooth enough and didn’t really miss the tunability compared to, say, a Formula Selva R or Cane Creek Helm.

Where I did struggle a little was with the IRT, but it’s important to stress that at just under 80Kg, I’m not the heaviest rider. Historically, I seem to be optimised for 160mm of travel. Every 170mm fork I’ve run, I’ve struggled to use the last 10mm, and this was true for the Mezzer Pro too.

Lowering the main spring pressure to get 30% sag did a little to get me using more travel more consistently, but still almost never full travel. To be honest, I don’t obsess about this, because it can depend on where and how I’m riding that day. If the fork feels good and is using most of the travel through the rough and dropoffs, that’s fine and it’s nice to have a bit extra in reserve.

Manitou Mezzer Pro Fork
Just the right amount of tuneability, not too much fiddling

For the sake of completeness though, I wanted to see how tunable it was, and consistently getting full travel seemed a suitable goal. In the setup guide, it specifies -10PSI to the IRT for trail riding, and +10PSI for downhill. Dropping 10PSI from the IRT didn’t change much for me in terms of travel use; it’s really a very effective bottom out bumper. Nice to have when you’ve set your fork up but are pushing your limits and trying new things.

Some other articles and documentation on IRT equipped forks seemed to indicate a wider range of pressures. So, after starting with the default of just under 54PSI in the air spring, and 83PSI in the IRT, I tried dropping the main spring pressure first. That resulted in more than 30% sag and predictably, a slightly boggy, mid-travel feeling for my riding style and the steepness of the trails I was on. So, setting the air spring back to a minimum of 54PSI, I set about experimenting with the IRT. Many rides later, I ended up with 70PSI in the IRT and 54PSI in the main spring. It still tended to leave a bit of travel on the table, but it was consistently using more and still felt good.

Apart from that one way-too-soft one, in all the experiments I did with the air spring, the Mezzer Pro was good at resisting mid-travel bogginess. This also manifested in successive big hits, where it seemed to recover quickly and never sit in the travel.

Between me and a housemate borrowing the bike regularly, this fork got absolutely hammered for several months straight, but didn’t stutter once.

On the whole, the Mezzer isn’t as comprehensive or plush as a Selva, nor as simple as a Pike or Lyrik. I’d put this on a par with Cane Creek’s Helm in this respect – it can take a little effort to get the right settings, and overall it has a bias toward going faster and hitting things a little harder. Way overkill if you live somewhere flat and made of dirt, but if you live anywhere steep and/or rocky, it has a wide enough variety of settings that’ll work.


The Manitou Mezzer Pro is stiff, firm, accurate and feels light relative to its burliness and travel. It’s not quite the most tuneable fork out there, nor the least. This is on a good level for people who want to be able to tweak their suspension, but not obsessively. Well suited to riders who want to plough through the choppiness without tuning it all out, knowing they’re on a solid platform.

Manitou Mezzer Pro Fork
Mezzer Pro: did well under testing conditions.

Review Info

Brand: Manitou
Product: Mezza Pro
From: Hotlines
Price: £899.99
Tested: by David Hayward for 5 months

David started mountain biking in the 90’s, by which he means “Ineptly jumping a Saracen Kili Racer off anything available in a nearby industrial estate”. After growing up and living in some extremely flat places, David moved to Yorkshire specifically for the mountain biking. This felt like a horrible mistake at first, because the hills are so steep, but you get used to them pretty quickly. Previously, David trifled with road and BMX, but mountain bikes always won. He’s most at peace battering down a rough trail, quietly fixing everything that does to a bike, or trying to figure out if that one click of compression damping has made things marginally better or worse. The inept jumping continues to this day.

More posts from David

Comments (6)

    Like the retro Manitou graphics! Takes me back.

    The HBO means you’ll need a stupidly big hit to get the last few mm of travel. I’ve got a mattoc and the twin positive air chamber is amazing. doesn’t take long to get it set up.

    My pet hate.
    Why it the back of the arch machined out, not the front? Purely for appearance, and it makes very little difference when the arch is at the back.
    It’s a PITA to clean, and any weight benefit is gone at the first sign of mud.

    I thought that about the mud collecting arch too. I suppose at least it’s easier to clean out than it would be at the front.

    They could easily make the mudguard fixing plate big enough to cover the back of the brace. It’d weigh less than all the mud that could fit in the holes!

    I didn’t find mud collection there to be a bigger problem than with any other fork.

    The stancions and the seals stay “cleaner” than with frontarch

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