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Teardown and Rebuild

MRP Hazzard Shock Teardown

Photos Deniz Merdano
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Dudes of Hazzard

Around here, it seems that our ethos dictates that running a product to failure is proper testing; finding the intended use case and hammering it so we can stand behind our inevitably biassed (but hopefully entertaining) opinions. We don't set out to break things or intentionally make them underperform, but the amount of riding we do and the unkind terrain we play on has an air of brutality.

I like a well-performing bike and heck, so do you; suspension that is supple and gear that changes with each click. Forgetting about it all, while focusing on the raw beauty around us, is impossible without well-oiled equipment

Sometimes overlook a component that has been working hard for us. And then we have to pull out all stops to rescue a failing relationship, and show we care.

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230x60mm MRP Hazzard with many hours on the clock. It also comes in all the metric and imperial sizes including E-Bike versions with heavier shim stacks

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To be taken care of at the S4 Suspension centre in Whistler, BC

The MRP Hazzard coil shock mounted to my Orbea Rallon is one of those products. For the past 2 seasons, I ignored the passing of the 150 hour interval when service was first necessary. After 300 hours, I did nothing to it. Not out of laziness or ignorance even; the damn thing just kept working flawlessly and consistently. After the addition of the Sprindex coil, I was just fine with how my bike rode trail after trail. The Orbea Rallon is a split pivot, link and yoke driven suspension platform. That means the rear-end of the bike is stiff but not immune to side loading the shock to some degree. That said, the rocker links are burly and supported well against the frame and the yoke is short and designed to allow the shock to rotate if there is extreme flex at the seat stays.

The Hazzard is a burly shock designed to take the abuse a long travel bike can dish out. The heart of the shock is the massive 14mm shaft that keeps the internals on the inside, where they belong. We, and by we, I mean Guillaume of S4 Suspension, grabbed the Knipex Pliers (famous amongst the wrenches of the world) and removed the IFP from the shock. Disgusting black sludge pours out onto the liquid tray as Guillaume spurts out sounds of disappointment in me.

"Hey man! That's why we are here, to document and celebrate the resilience of this piece of equipment" is my response.

He is not impressed. Guillaume is a pro. He genuinely loves making suspension work better. He hasn't had the opportunity to dive into many Hazards but within minutes of turning wrenches, he is right at home. The heart of the shock is actually an Elka Stage 5. When MRP acquired Elka's bicycle division, the tooling and all the patents were included in the sale. This acquisition only meant good things for the users, as Elka wanted to shift their focus to the motor racing and offroad sectors. This was in 2013 and I imagine they may be regretting that decision. Mountain biking seems to have caught on.

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Shim stack comes off as one piece.

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If you wish to leave it assembled, you can do so and change the oil in the damper as needed

The Hazzard is built like a moto shock. The oil flow, the damper construction, the hardware and the sheer size of the shaft, all indicate simple goals; reliability and long term durability. With the damper out of the shock body, we see a self contained shim stack. This means if one is just servicing the shock to change o-rings and oil, you don't have to mess with separating the shim stack in the process. It can be put aside without worry. We wanted to dive a little deeper though so Guillaume took this one apart. Some of the parts that need to be unthreaded needed a little convincing from our friend the torch but overall it was trouble free.

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Organized chaos

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Customer's suspension either done or waiting to be done

The Hazzard was free of leaks when we embarked on this teardown. Which is another reason it was neglected. If there wasn't an obvious problem, there didn't need to be an intervention either. The Shaft had minor scoring that could be felt with fingernails but the lack of oil on it was a great sign. 30 seconds on the lathe with an emery cloth later, the score-free, shiny shaft was ready to go back into the shock body.

MRP's Hazzard manual is a little vague but the construction is simple enough for anyone who has opened a shock before. The IFP chamber is the most difficult one to decipher as far as removal and IFP depth goes, but Guillaume had zero trouble figuring out the right way. A strap wrench broke the IFP chamber free and we were on our way deeper into the teardown.

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some more heat to get it moving again

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off comes the HSC circuit

The Compression circuit at the base of the IFP chamber also required a hit from heat, proving these little propane torches are one of the most useful tools in one's arsenal. They make quick work of removing stubborn fasteners and save you a ton of headaches from stripped wrench flats.

The o-ring sizer came in handy in figuring out the right replacements and everything was of standard size which made it extremely easy to source with no preparation on our end. The shop is only as good as the diligence of the people running it and the layout of the S4 is compact and efficient without sacrificing inventory or tools.

Once the compression circuit was in the vice, it was cool to see a simple solution to a problem that I didn't know existed. There is a sliding, keyed button that keeps the compression knobs at a constant height no matter how far you turn them from open to closed. This isn't how it works on other shocks and afterwards I began noticing this. The compression dials on the Fox VVC dampers move in and out depending on how far they are turned. Despite causing no drawbacks whatsoever, they annoy me now.

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Light scoring on the shock shaft

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30 seconds on the lathe and an emery cloth later

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shiny and mostly score free for more abuse

Guillaume went back and forth from his parts bin in the back while we chatted about shocks and bike technology in general. The greasy hands of the bike world will always have strong opinions about the construction of mechanical parts and the way they are serviced. The serviceability of bike parts varies immensely from brand to brand. From full rebuild kits available at any bike shop to, "let's go through the dark web to find the correct IFP height during bleeding" kind of ambiguity. There are no benchmarks for servicing.

With most shops charging a flat rate to bleed brakes, how does it even out when a Shimano bleed can take 15 minutes while it may be an hour on Hopes or even Hayes.

Suspension centers like S4 take great pride in doing things fast to get you back on the trails. Their appointment-based system is aimed at getting your stuff back to you the same day, or a couple of days later at the worst.

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cocktail bar, with the far right option is the Motorex synthetic going in the Hazzard, and in most shocks that come for service

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IFP height set to 24ish mms for bleeding

Your fox CSU may be creaking and in need of a warranty part from the manufacturer but S4 seems to stock most spare parts and can even press stanchions into crown arches for you; tooling that is not cheap. You'd think a place like Whistler, that shifts from summer to winter sports in a matter of weeks, would be a tricky market. Miriam tells me that winter is the busiest time for S4's Whistler facility, when people hang up their bikes for their skis and sleds. Summer is quiet with the suspension of the locals being slowly demolished by bike park laps. Only emergency repairs are injected into the daily hustle.

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Dyno testing was immediately successful

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Stainless steel benches are for keeping settings recorded.

Digging deeper into the shim stacks, Guillaume doesn't see anything alarming so a cleanup and re-lube is all that is necessary. Then comes the bleeding of the IFP for an air free damping experience. There are a few oils to choose from in the tanks. The Fox shocks mostly get their own fluids depending on if they are being warrantied or are an older shock getting a refresh. The MRP got a healthy splash of Motorex and Guillaume seems to prefer this oil. The bleed takes no time and is painless judging by G's facial expression. The IFP on the Hazzard is at low pressure which helps a lot with reliability. 150psi is all it needs.

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Myriam, Jacob and Guillaume

The shock was mounted on the hand dyno and there were no surprises. It was a great exercise to see the inner workings of the Hazzard and to check out S4 Suspension in Whistler. It's now one of my top places to get suspension work done in the Sea 2 Sky. The attention to detail and the passion behind the name is evident in every shipment that comes in and out. You may even get treats with your suspension when it arrives home; maybe a special air cap or a hand-written note from your tech. Miriam tells me people will often send in beers and treats with their destroyed equipment to soften the blow.

This place runs like clockwork but also like family. They bicker and joke and overall enjoy their time in their space in Whistler's Function Junction. S4 headquarters are in St. Jerome, Quebec while Whistler is a satellite shop, leaving the country well-covered by their expertise. Guillaume and Miriam spend a lot of time in each location throughout the year, making sure everything is running as smoothly as possible. Not an easy task I imagine.

The Hazzard we tore apart went back on the Rallon the next day and it was a stark difference in plushness and feel. The bike is significantly more composed and has more rear wheel traction after the teardown. Degradation happens so gradually that you don't notice how bad it has gotten over time. Take those bits apart before the best riding of the year kicks off, at least around here that is.

Make sure you swing by S4's Whistler location next time you are in town. Bonus points: The Pure Bread bake shop is just a couple of doors down.

Win win..

S4 Suspension Center

MRP Hazzard Shock Service Manual

Deniz Merdano



Playful, lively riding style

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+3 bishopsmike Skooks ohio

Great writeup on what sounds like a great shock being rebuilt by a great service center.

Is it feasible to use S4 if you're down here in the southern part of North America?!


+2 Andy Eunson Skooks Velocipedestrian Briain Dr.Flow PowellRiviera dhr999 Cooper Quinn

Knipex Pliers Wrench. To ignore the full name is to ignore what makes them special: that they are a valid replacement for a wrench, unlike plain pliers.

Knipex makes a bunch of high-quality regular pliers and pipe wrenches, but the Pliers Wrench is special, and should be treated as such.


+2 bishopsmike Kos

I get my shocks and forks serviced by S4 annually. I love the appointment option as I only need to be off the bike a day. I’ll bring the fork or shock in the afternoon before and pick up next day. No issues dropping by to ask questions either. Being a ten minute walk from home helps too.


+1 Kapolczer

I have used them for my Fast Fenix EVO shock (am in Arizona) and they were excellent. Having an office in BC vs Quebec is just a bonus.

Always appreciate and enjoy these types of articles, super interesting to see not only the shock innards but also to see some of how a shop built for scale work is setup and structured.


+1 ohio

They should sell those work shirts. With “Bill’" embroidered on it. At one time at the original Syncros shop, they all wore them but the name was "Bill" on all of them. My recollection of the joke was that every machine shop had a guy named Bill. So that’s what all the shirts said.



It's helpful when the Olympic Annoyer comes in, he's always grumpy at Bill.



I've used S4 Whistler and its previous incarnations back to the Vorsprung days for years now and only had positive results.



Love a tear down! Great article and what a great shop.



Really enjoyed this.  Have a Hazzard and nice to see it get some attention.  And a very impressive look inside a suspension service operation.



I love, love, love these teardowns, please do more! More enjoyable than tearing down your own shocks/seatposts/forks, even though I have to do that too.



Great article, appreciated!

One question: What material is the shaft made of? I ask because I have had two MRP Hazzards (trunnion mount) which failed both within < 3 months. The first one (black anodized aluminium shaft) began to squeak and seized due to a failure of an internal seal. Then I got a replacement which had a shaft made from stainless steel with a somewhat rough finish. I was told this "custom hand polish" would carry a bit of oil to make the shock even more plush (no joke). Due to being quite soft, the shaft was showing wear marks quickly, but I was told this would be no problem. Which it indeed wasn't, until a serious amount of oild leaked out of the shock. This was the point for me to say goodbye to MRP.

Btw: Running a SR Suntour TriAir for 1,5 years now which is running flawlessly and performing great.



Still one of the most desireable shocks on the market, just wish I could afford one! Really nice write up on service


-1 Kristian Øvrum dhr999 DancingWithMyself

What shocks require disassembling the shim stack to change the oil? I've only opened, or helped with, a half dozen different shocks in various configurations (inline, piggyback, upside-down), and all of them allowed changing the oil without taking the stack apart. Only time I've had to take apart the piston stacks for purposes other than changing the shims was to change stroke length.

Not that it coming off in one piece is bad, just genuinely wondering why it's notable re: regular maintenance.


+2 Andrew Major DancingWithMyself

Possibly removed just for inspection? The mention in the article that shim removal isn't required for an oil change/bleed. Among different manufacturers, not all shims are created equally, and some shock designs are harder on their shims than others. For example, the shims in Fox RC/Marz CR have notoriously short lifespans.


-1 Kristian Øvrum dhr999 DancingWithMyself

"The mention in the article that shim removal isn't required for an oil change/bleed."

This is not unusual, though, I don't see why it's worth mentioning. "If you wish to" you can keep the entire stack on the shaft to change the oil, just like anything else. The removability is just a quirk of their design, how they chose to hold the piston to the shaft. It's not functionally better or worse than other designs, despite the implication that it's something special and useful specific to this damper. That's why I asked if there is a damper out there that would contrast to this one and require shim removal for an oil change.


+3 dhr999 DancingWithMyself Deniz Merdano ackshunW Kristian Øvrum

Perhaps the wording of the article is to make it clear to everyone (not just those familiar with common shock arcitecture) that the shims don't need to be removed? Certainly doesn't hurt to describe it the way Deniz did, aside from inviting extreme cases of nitpicking.


+4 Cooper Quinn Deniz Merdano Mammal ohio DancingWithMyself Kristian Øvrum

If you are doing a full rebuild, you will replace the seals in the seal head/bearing as well. This requires removal of the shim stack, so you can pull the seal head off of the damper shaft.

I have never heard of  a shop changing the oil without putting fresh seals in at the same time.

This design makes it slightly easier as the shim stack remains captured and you can't accidentally end up with a pile of loose shims on the floor.


+1 Deniz Merdano


+1 Kristian Øvrum

Now there is an answer. Still, it's not about changing oil specifically, it's about full rebuild.

Though I would argue that I've never heard of a shop that would (and I wouldn't personally) change the seal head without disassembling the stack and inspecting the shims as part of "full rebuild". Especially with allegations such as: "the shims in Fox RC/Marz CR have notoriously short lifespans" floating around.

However, you did find a single reason to remove the piston & shims as one piece.



>the shims in Fox RC/Marz CR have notoriously short lifespans 

This is new information to me, I'll cross my fingers - my Bomber CR coil is away for a rebuild, and I'm looking forward to a usable rebound range upon return.



"50-60hrs" is the feedback I received. Both yearly services they did my Fox RC included new shims.



That does seem short. Do you run heavy compression damping? 

I assume this would effect the lifespan, and I run mine pretty light.


+1 Velocipedestrian

Nope. When I was on that RC, I believe I ran compression near the middle, but the rebound was pretty close to closed (perhaps due to shim performance?). 

I was told by the tech (my long-time friend) that the shims are basically over-worked by design, and they're all that way. This is in the context of the Fox RC, but everything I've heard about the Marz CR is that they're basically the exact same shock. In a separate context (rebuilding X2's I believe), the same guy told me the newer Fox shims are made of worse/cheaper material compared to older ones, and other brands, and don't last as long as a result. I'm not sure if this would be model-specific, but I wouldn't assume so.

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