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Review

SR Suntour's Zeron Fork - Bargain Coil Goodness

Words Cam McRae
Photos Cam McRae
Date May 6, 2021
Reading time

For a few years now it has seemed like the big guns would be bringing out a coil-sprung, long-travel, single-crown fork. Fox has sort of done that by using the Marzocchi name with the Z1 Coil, but I haven't yet seen anything under the Rockshox or Fox Shox banners. Now I'm starting to wonder if they will ever come, and I hope they do. Coil forks are simple, smooth, reliable, and relatively inexpensive to manufacture and maintain. The absence of seals to keep air in the proper chambers means stiction is reduced, particularly off the top of the stroke. Forks sprung with a steel spring are not particularly sensitive to altitude, and are much less fussy about temperature (but you may need to speed up the rebound damping). You never have to check your air pressure and a spring's linear rate provides the sort of plushness air forks can only hiss about.

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There are no volume spacers to install, no chambers to equalize, only one rebound knob, only two spring weights, and the compression is either open or locked out.

When I caught wind of SR Suntour's Zeron coil, thanks to Andrew Major's recommendation, I was keen immediately. With a retail price of 676 CAD/550 USD, it comes in well under the Z1 at 1049 CAD/776 USD. They are different beasts to be sure however; the Zeron can be had in 130, 140, or 150mm of travel while the Z1 coil 29 is either 150, 160, or 170mm, adjustable with spacers. Beyond that the damper in the Zeron is a simple sealed unit while the Z1 ships with Fox's effective and reliable Grip damper, the Z1 has 36mm stanchions, vs. 35 for the Zeron, and the Zeron is actually about 100g lighter. Probably the biggest difference however is that the compression damping is adjustable on the Z1, and while there are detentes in the Zeron's 'Lock Out' lever, it seems to be primarily on or off.

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It's a nice silhouette, but I share Andrew Major's ambivalence about the graphics. To me, when those sorts of details are done well, it shows that somebody cared enough to put in a solid effort.

I set up a perfect storm for the mild-mannered, no-nonsense, dentist-repelling, Zeron. First of all, I was mounting it on my Kona Honzo ESD hardtail, so good rear suspension kinematics wouldn't help smooth any rough edges. Secondly, I was putting it back-to-back with one of the best forks currently available, a Fox 36 Float Factory GRIP 2. And C, the final trap I was setting for the Zeron, was mounting it subsequent to an over-forking scenario. The Honzo ESD, which ships with a 150mm Marzocchi Bomber Z1 Air, got bumped up to 170mm up front with the 36 Factory, and the Zeron is only 150mm. Really it wasn't a fair fight, despite the Zeron's wound steel secret.

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Rebound was the only knob that needed any twisting, and it was easily nailed the first time.

The Zeron arrived with three springs; a 140 and a pair of 150s, rated firm and soft. With the firm installed, I mounted the fork, adjusted the rebound in about 100 seconds, made sure the compression was open, and pointed it toward the trails. The Zeron did have minor leg up and that was a rider who had already suffered through the first semester of the hardtail refresher course and was re-gaining the confidence to ride like it's 1992. The element of hardtailing I'm appreciating most is how imperative it is to ride with the best technique I've got. You can be sloppy and survive on a long travel enduro sled, but the cold steel mistress will never allow such behaviour to go unpunished. The ESD distills my fermented focus into Everclear and leaves me no choice but to ride clean.

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I had no need to ramp up the preload knob (non-drive side) or the lockout, which is of little use off road on a hardtail.

I'd been taking a hiatus from the hardtail before installing the Zeron but after the first pedal stroke I was glad to be back. Once I started rolling downhill, the weirdest thing was how little I noticed. There was no excessive noise, the mid stroke-support was pleasingly solid, and the fork moved effortlessly off the top of the travel, and at any time an impact was felt. The part that pleased me most about the seemingly dialled setup, was the fact that it had taken well under five minutes to accomplish. On more sophisticated suspension products it's generally several rides at least before I manage anything resembling a sweet spot.

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The captured axle is a nice piece of engineering. To push it into the fork you simply need to apply some pressure and the little collet compresses in the QLOC32 axle.

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To remove the axle, after the QR is open, simply. press the end of the axle like it's a button and the collet clicks into its compressed circumference and stays there until you release it.

About the best compliment I could give the Zeron is that I couldn't have been much happier. I never once wished for the Marzocchi Z1 or the Fox 36, despite both being excellent, high-performing platforms, and the 36 having several more adjustments and 20mm more travel. One thing to consider however is that I rode the ESD in 36 mode on more challenging terrain. For the last two weeks of my Zeron test period I was quarantined because a family member tested positive for COVID-19. Everything worked out in the end, the illness was mild and none of the rest of us caught the virus, but my riding options narrowed significantly. As part of our quarantine we were allowed to go for walks, particularly when our dog was involved. My dog 'walking' was performed while riding mountain bike trails, and in particular, trails that aren't in heavy rotation for most riders to keep encounters at an anti-social distance. Beyond that I was staying close to home so Mount Fromme was in, but Boogie Man on Seymour and Fifth Horseman on Cypress, were out. The amplitude of moves and the magnitude of impacts on either of those trails is a level up from the Fromme trails I was riding, despite more than enough challenging technical terrain.

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As Andrew pointed out in his review of the SR Suntour Durolux 36 EQ, the elegant axle design allows the dropout castings to be simple and clean; no clocking mechanism, no threading, and no bolts required.

The first attributes that struck me were suppleness and support. The Zeron was riding at a generous height but moving easily into its travel when larger impacts occurred. And despite feeling like the spring rate was perfect for my weight and riding, I never seemed able to find the bottom. In fact after many rides I seemed to have another 10mm of travel yet to be exploited. In a perfect world this is the setup I'd like because that unused travel could come in handy when things go haywire. It's harder to run an air fork with this much reserve travel because the progressive nature of the air spring can make the ride too harsh.

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Preload is available for those who feel the need.

  • 130-140-150mm internal travel settings (ships at 140mm)
  • Requires spring kit to increase or decrease travel ($30 or so)
  • Coil spring design
  • Lockout
  • Rebound adjustable
  • Preload adjustable
  • Forged aluminum crown
  • Integrated front fender
  • 35mm A6000 black anodized stanchion
  • 15x110mm Q-LOC32 Boost through axle
  • Lower chassis made of magnesium
  • Steerer tube AL7050 1.5-1 1/8" CTS
  • Note: 15x110mm QLOC32 included
  • Fender included
  • 29 x 2.4" tire compatible (2.6 works fine in my experience)
  • Weight 2485g
  • 2 year limited manufacturing warranty
  • Axle to Crown for 29 set at 140mm travel = 560mm
  • Fork offset for 29 = 51mm
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The including fender is the best OE mud guard I've encountered. It attaches easily and the wide placements make it very stable.

This is one of those times when I don't have much else to report. The Zeron is capable, smooth and plush on bumps both small and large (or at least as large as I've attempted), it's sturdy and well constructed, and while the adjustments are few, I was easily able to find a very well balanced ride. I will however have more to say when I receive the slightly fancier, but still reasonably priced (600 USD) AION35 BOOST RC PCS 15QLC 29/27.5+ and I compare the two back to back.

Head here for more on the SR Suntour Zeron BOOST LO R 15QLC 29

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Comments

Bikeryder85
+2 papa44 Cam McRae
Bikeryder85  - May 6, 2021, 3:07 a.m.

Thanks for this, I would love a coil fork to go with a new 29er frame and love options from the "other" brands. Currently on an x-fusion (27.5) with no complaints but their coil conversion kit seems to be vaporware.

Reply

papa44
+2 Cam McRae Pete Roggeman
papa44  - May 6, 2021, 5:16 a.m.

I have an x-fusion trace which I really like, even though it’s non boost so basically obsolete and I also have a rock shox rl 35 gold which I’ve been dead happy with for the price too. I get the feeling that below £/$500 you get an exceptionally useable fork no matter who you go with, so a budget coil fork would be super interesting and I’m sure it would be great for the price too.

Reply

ackshunW
+6 Cam McRae Dan Pete Roggeman Timer Derek Baker Tjaard Breeuwer
ackshunW  - May 6, 2021, 4:04 a.m.

Oof ugh, I guess it’s true that I’m really behind the times. $550 for a bargain fork with no compression adjustment sounds like a lot to me! Slowly recalibrating my value gauge....

“Plushness air forks can only hiss about.”  —— pure gold!

Reply

AndrewMajor
+5 Lu Kz Cam McRae mrbrett Dan Greg Bly
Andrew Major  - May 6, 2021, 7:39 a.m.

I have ridden quite a few budget forks, and I can’t think of one with adjustable LSC where adding compression damping doesn’t just make the fork exponentially shittier. 

Whether it’s RockShox, or Fox, or X-Fusion, or Suntour, or etc the recipe for best possible performance is the same:

1) Lube lowers out of the box

2) open LSC

3) run Rebound as fast as you can hold on

Actually, one of the best budget dampers is the newer version of X-Fusion’s RL damper. It’s buttery off the top but actually has quite a bit of mid-stroke support thanks to the check-valve in the damper. Open the rebound so it recovers quickly and go ride with your friends on forks that cost double.

I’d much rather invest my money in a really nice chassis than extra knobs that do nothing or make my fork worse.

Reply

taprider
+1 Andrew Major
taprider  - May 6, 2021, 9:15 a.m.

I've been running the Suntour Axon Werx 34 for a couple months.  I run rebound and compression damping fully off, and after lots of experimenting have settled on one volume spacer (which is half the size of a Fox spacer).  I've got it working well enough now for North Shore XC (like trying to go faster than elite trail runners down Neds - who bound like deer and faster than most "Trail" bikers), but it seems too over damped when it is colder and doesn't soak up the small trail chatter as well as my 2010 Fox 32 (but better than my former 2017 Fox 34 (not step cast)).

I emailed Suntour and they told me the cartridge is not modifiable (such as by changing shims, spacing between components etc.).  But am wondering about changing the cartridge oil to something even less viscous (Suntour already uses a low viscosity and weight oil)?  And what do you think of the quality of Suntour's seals, any chance to reduce a bit of stiction?

Reply

AndrewMajor
+2 Mammal taprider
Andrew Major  - May 6, 2021, 9:22 a.m.

If you haven’t already, drop the lowers - add ~5-10cc of Fox 20W oil to each side and generously Slickoleum the seals. 

If that doesn’t get you there, my wife’s Auron RC2 is amongst the nicest forks I’ve felt after it had a spa day at SuspensionWerx.

Reply

taprider
0
taprider  - May 6, 2021, 11:06 a.m.

yes, I added 10cc of oil first thing

Funny or weird thing is that I have five bottles of fork oil (none of which are Fox), a jug of synthetic motor oil, and three different types of fork grease (none of which are Slickoleum)

I was thinking of the spa day already ;-)

Reply

mammal
+1 ollyh
Mammal  - May 6, 2021, 12:20 p.m.

Fox 20Wt Gold works wonders on most fork lowers. It's worth keeping a bottle around, especially since a lowers service should usually be done around twice as frequently as a full rebuild.

AndrewMajor
+1 ollyh
Andrew Major  - May 6, 2021, 1:07 p.m.

*shrugs*

If you swap the Dark Rum for Fireball and the Ginger Beer for Fanta I don’t know WTF you’re drinking but it isn’t a Dark n’ Stormy.

——

“If you haven’t already, drop the lowers - add ~5-10cc of Fox 20W oil to each side and generously Slickoleum the seals.”

reini-wagner
0
Reini Wagner  - May 6, 2021, 1:33 p.m.

I had an Auron RC2 PCS on my Honzo AL, that was a great fork, so much bang for the buck. Unfortunately someone liked the bike well enough to break through two locked doors and one Abus bike lock to get his dirty hands on it :(

Reply

taprider
0
taprider  - May 6, 2021, 1:37 p.m.

^Andrew

So I think you are saying - don't use Rock Shox Red Rum

Reply

Jotegir
+1 Andrew Major
Lu Kz  - May 6, 2021, 9:31 a.m.

1) Lube lowers out of the box

2) open LSC

3) run Rebound as fast as you can hold on

Amen.

Reply

nothingfuture
+2 Dan Derek Baker
nothingfuture  - May 6, 2021, 5:10 a.m.

God I miss a coil fork.

I had a Z1 in, like, 2001? Ish? And while the coil was amazing, it was (for me) the simplicity of the secondary tuning that made it special. Sure, the springs were linear (unless you were some sort of unwashed barbarian and used pro-wound springs...), but if you wanted more bottom-out progression, you could run a bit more oil in the damper and be all set. Never mind that most of the maintenance was dumping the old oil, flushing, and putting new oil in. 

What does this SR Suntour fork have for a damper? Is it open oil bath? Sealed? Something else?

Inquiring minds want to know.

Reply

cam@nsmb.com
+3 Dan nothingfuture Derek Baker
Cam McRae  - May 6, 2021, 9:43 a.m.

It is a sealed damper. I have a bit of a damper plan for later on but it’s provisional and I’m not going to say more until the opportunity is clarified.

Reply

kos
+1 Dan
Kos  - May 6, 2021, 5:54 a.m.

In bizarro world, this fork is listed by Suntour NA as both on sale and sold out.

Was ready to pull the trigger!

Reply

papa44
+3 Cr4w Cam McRae Dan
papa44  - May 6, 2021, 6:22 a.m.

Yeah it’s a shame, out of stock yet super  cheap at the same time. It’s practically quantum suspension.

Reply

cam@nsmb.com
+2 Dan Kos
Cam McRae  - May 6, 2021, 9:48 a.m.

Apologies for that. I was attempting to get some more info about availability but haven’t yet been successful. That price is crazy in this age of hyper mountain bike inflation.

Reply

dan
0
Dan  - May 6, 2021, 10:11 p.m.

Came here to see if anyone else had noticed that. I also checked the "Demo to your Door" Program that SR offers, and that appears to be on hold, AND the ZERON wasn't an option anyhow.

Reply

SteezeMcQueen
+5 Deniz Merdano Cam McRae goose8 jaydubmah Tremeer023
SteezeMcQueen  - May 6, 2021, 7:10 a.m.

"The ESD distills my fermented focus into Everclear and leaves me no choice but to ride clean."  Poetry!

Reply

Shoreloamer
+6 Andrew Major nothingfuture Cr4w Cam McRae Dan twk
Greg Bly  - May 6, 2021, 7:26 a.m.

Cam I think this is the first time I have read about a ( cheap fork)  in an un biased manner.  You did not let the low price effect your oppinion. 

It's the best looking fork Suntour has made to date. Has the correct support feels like your using all the travel but have ten percent in reserve. That's my description of the perfect fork. 

They need to make a coil Durolux , with an air negative spring. With these subtle grafix.

Reply

AndrewMajor
+4 Greg Bly Dan twk Tremeer023
Andrew Major  - May 6, 2021, 7:42 a.m.

Have to agree on all counts. Great review, more subtle graphics would sell more forks, and I’d definitely try a coil kit in my Durolux.

SR Suntour is a big enough outfit maybe they could even offer progressively wound fork springs?! To my mind that’s what’s missing from high end coil forks.

Reply

momjijimike
0
momjijimike  - May 6, 2021, 7:33 a.m.

Sounds like a great fork which would fit into my hardtail. But why no compression adjustment? 

Do you know the lbs/in for the firm spring? Thanks!

(LSC +- is very important on my Öhlins coil... so I'm not sure about the Suntour...)

Reply

AndrewMajor
+2 nothingfuture DadStillRides
Andrew Major  - May 6, 2021, 7:50 a.m.

A replacement damper for your Ohlins fork isn’t all that far off the price of this entire fork.

As I noted above, I have a decent amount of experience with budget forks and can’t think of an example where the LSC adjusters on basic dampers don’t make the forks feel worse the more clicks you add. When it comes to budget suspension, as a general rule less damp / more ramp is better.

Stoked your Ohlins works great for you (awesome forks) but I do also think mountain bikers in general are too obsessed with fiddling with their knobs.

Reply

papa44
0
papa44  - May 6, 2021, 9:33 a.m.

What would be your to 3 budget forks? Any order. It’s really hard to find solid cheap fork recommendations and I can guarantee I will never need a top flight set even in the alps.

Reply

Hollytron
0
Hollytron  - May 8, 2021, 8:57 a.m.

Z1, Z2 and I have my eyes on a durolux. The Z2 is great for trail bikes. I have a 120 version on the HT and it is awesome. Gotta echo the service out of the box thing the z2 rode night and day better with a lowers service and adding foam rings.

Reply

tashi
0
tashi  - May 6, 2021, 8:39 a.m.

As a long time rider fed up with modern pricing I’ve been curious about Suntour forks for a while but anyone I know who rides hard has had less than stellar reliability. 

A coil version might be ideal at this price point, probably easier to build reliably than an air fork.

Reply

AndrewMajor
0
Andrew Major  - May 6, 2021, 8:55 a.m.

Any more information on what models and what issues? 

I have a number of friends and acquaintances on Auron and Durolux forks who’ve had great experiences. Chassis reliability (creaking, porosity) has been way above par and they haven’t required any more service than other forks for similar usages. 

I my experience, Durolux EQ likes a little more frequent lowers service than the previous coil-negative version but it’s still no more frequent than anything else I’ve ridden.

Reply

tashi
0
tashi  - May 6, 2021, 10:51 a.m.

I don’t remember any details and I’m a few years out of date.

Reply

Andeh
+2 Cam McRae Dan
Andeh  - May 6, 2021, 12:07 p.m.

I can't even imagine how slowly a backwards mounted Assegai rolls (last picture).

Reply

cam@nsmb.com
+2 AJ Barlas Dan
Cam McRae  - May 6, 2021, 1:04 p.m.

Lol. I was going to add “what’s wrong with this picture” to the caption but I forgot. 

This was the end of a day doing 6 tire and insert swaps and by the time I noticed I was  too shot to fix it. And then when I checked the rear I’d done the same thing! 

Got the logos lined up though! #facepalm For science I’m going to try it to see if I can notice any difference. Are those little ramps simply cosmetic or do they perform any noticeable function? I imagine braking might be compromised but rolling? I’m not so sure.

Reply

gdharries
0
Geof Harries  - May 6, 2021, 1:49 p.m.

A previous version of this fork came on my 2018 Norco Torrent HT which I no longer own.

The fork was overly harsh at first, but lubing the lowers and seals made a big difference. I also learned to appreciate the elegance of their axle system. The fork was also very stiff, flex-wise. But, it always felt, cheap.

Would I pick it over a Z1, Pike or Lyrik? No, but that's not comparing the same fruits.

I did replace it with a Z2 Bomber after one season. To me, the Z2 is a better fork and worth the cost to upgrade if you can find someone to buy the Zeron. I couldn't. Everyone wants the RS, Fox or Marzocchi brand name.

Reply

SteveR
0
SteveR  - May 6, 2021, 1:58 p.m.

Noticed the positive comment on the fender. It looks the same as the one supplied with my current model Auron 35 that, no matter what I do, (grease at interfaces, cut back slightly where it was almost touching the crown) continues to be the source of some annoying noises. It's off right now- silence at last. Other than that, I have been impressed with my first couple of dozen rides on the Auron. It was dead easy to set up and blows the MoCo damped Revelation that I was running out of the water on all aspects of performance, at a substantially lower cost.

Reply

DadStillRides
0
DadStillRides  - May 6, 2021, 8:24 p.m.

I also had a MoCo Revelation that came in 130 on my Ragley Piglet. Similarly felt the need to switch it out. After looking at all the options I just swapped out the damper to a charger 2.1 and "upgraded" to the new properly designed debonair spring. I have been surprised how much this has improved the ride without increasing travel. Might be worth checking out if you still have the revelation and want to put it to use again. Mods required less than $300 (USD) and an hour in the garage if you know what you are doing (longer for me).

Reply

SteveR
+1 DadStillRides
SteveR  - May 7, 2021, 6:49 a.m.

Was aware of that option, but after reading Andrew's reviews, I thought that I would give something different a try. No regrets.

Reply

extraspecialandbitter
0
ExtraSpecialandBitter  - May 6, 2021, 8:09 p.m.

I got a RM Instinct Coil this spring and the Cane Creek Helm has been quite nice.  It does cost more than double the Zeron though.  I found I needed to turn the high speed compression on it up quite a bit to stop from bottoming out, however I only noticed this on certain features, like on large drops to flat, or on rock faces with transitions that look like this 

\
 |__         

I'm very tempted to put this on my Chromag, but my only hesitation was that I'm too lazy to bump up the travel to 160.  I'll have to try it out at 150mm. 

When first feeling the spring, I was worried that it'd be too stiff, but when I'm riding it feels super smooth.

Reply

ketchupchips
+1 Dan
ketchupchips  - May 7, 2021, 6:55 a.m.

Just a little correction. On the Z1 coil it's possible to drop the lowers and move the spacers to adjust the travel. The 29" fork travel is 150 - 170 mm, and the 27.5" model is 160 - 180 mm.

Reply

cam@nsmb.com
0
Cam McRae  - May 7, 2021, 10:16 a.m.

Thanks for that! Appreciated.

Reply

Jenkins5
0
Jenkins5  - May 7, 2021, 10:36 a.m.

Nice review. This fork was interesting to me for sure (Price was too good to pass up) but in the end I wanted/needed 160mm. Ended up grabbing a DVO Diamond D1. Was $325 more ($999 CAD) but it feels way better than my last Fox 36 Grip damper for sure....I am interested to try a coil again at some point though!

Reply

kos
0
Kos  - May 21, 2021, 6:02 a.m.

Hey Cam, any insider info from Suntour on availability of this fork, other than the "Sold Out" listed on their website?

Thanks!

Reply

cam@nsmb.com
0
Cam McRae  - May 21, 2021, 10:01 a.m.

A third party does the consumer direct business for Suntour so I couldn't get a lot of info but I'll make another inquiry.

Reply

cam@nsmb.com
0
Cam McRae  - May 23, 2021, 9:49 p.m.

Here's what I got back:

I don’t think the sales office in Washington expects to see the Zeron till next year. Lead times are crazy. People can contact them directly for more info. https://www.srsuntour.us/pages/about-us#contact-us

Reply

kos
0
Kos  - May 24, 2021, 5:36 a.m.

Thanks for digging into this, Cam. I will blame you personally! :-)

In related matters, Helm Coil forks are not expected to be available until November.

Reply

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