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Forum Testing: Suntour Auron 34 RC2 PCS

June 30, 2017, 12:12 p.m.
Posts: 2271
Joined: Nov. 22, 2002

Thank you to everyone who applied. We were impressed by the quality of entries. If you weren't chosen, don't be disheartened - there were lots of criteria used to determine the four that we picked, and we hope to be announcing another forum testing opportunity very soon.

Our four testers have been chosen! They are: UFO, Taz123, pedalhound, and Jan.

Their forks are on the way, and they'll have their first thoughts posted in this thread very soon.

June 30, 2017, 1:47 p.m.
Posts: 9269
Joined: Nov. 19, 2002

I am stoked to be chosen as one of the lucky testers, thank you and SR Suntour for this opportunity. 

I am looking forward to getting these forks on my Banshee Prime. I decided to run the 150mm version of the Auron for this test, it will be a bit of a step up in travel for me as I have been running 140mm for the past few years. I will be testing these forks mostly on the rocky, rooty trails on Vancouver Island and hopefully a few late summer road trips to the mainland! 

Now...I just gotta wait for brown santa!

June 30, 2017, 4:36 p.m.
Posts: 479
Joined: Nov. 25, 2013

I couldn't have said it better Pedalhound. I'm very excited to be chosen. The fork will get the true North-Shore treatment  - so lets see how this 140mm 29-er chassis handles the chunder.

Thank you NSMB and SR Suntour.


June 30, 2017, 9:20 p.m.
Posts: 1285
Joined: Nov. 21, 2002

Thanks for the opportunity!

My tester fork will be mounted up to my Rootdown BA, running 29" front wheel and 27.5+ rear wheel. Main riding locales will be Eagle Mt and Burke Mt in the Tricities. I may also bring her up to the Whistler bike park as well, for science. 

I've also had some recent bits added: Zee 4 pot front caliper, and a Sunrace 11-46 rear cassette mated to XTR shifter. Looking forward to see it all come together with the new fork.

July 6, 2017, 2:51 p.m.
Posts: 36
Joined: Feb. 24, 2017

I'm Jan, the fourth tester, and am (impatiently) awaiting the delivery of the fork. UPS delivery is planned for next Monday the 10th, after which I'll be posting an unboxing, initial impression, and setup. 

I'll be testing the 150mm 29er fork initially on my 2017 Chromag Surface, followed by a longer test period on my Santa Cruz Hightower. I have 27.5+ wheels which I'll simply comment on fit, but fork testing will be on 29" wheels. 

My favorite trail areas to ride are Mt. Seymour, Bellingham, and Pemberton, however I'll be bringing this fork with me on a trip to the Canadian Rockies as well to Colorado in August. 

My experience with SR Suntour products is ... zero. I'll be honest and say that I often wrote them off as a base model OE - relatively low performance company. That changed when I saw Brett Tippie was riding their suspension, so if it is good enough for Tippie, who am I to judge. 

I'll primarily be comparing the fork with my experience on a 2016 Fox 36, so I'm excited to explore the performance of the RC2 system of the Auron. 

Finally I'll conclude with some appreciation to the NSMB editors and SR Suntour for including me in the testing group. Thanks!

refreshes UPS tracking

July 7, 2017, 1:50 p.m.
Posts: 9269
Joined: Nov. 19, 2002

I keep refreshing my UPS tracking too....seems to not speed things up...mines still in Richmond! Been a while since I wanted a Monday to get here so

July 11, 2017, 8:56 a.m.
Posts: 9269
Joined: Nov. 19, 2002

Brown Santa came while I was away at work and dropped off the sexiness! 

Knife in hand, but I needed to tease my Instagram followers!

First impressions are good! Looks like great quality, better first impression than when I unboxed my last set of forks (you can see those in the photo above) to get them all mounted up and subject them to my girth and shitty riding style..haha...

July 11, 2017, 10:56 p.m.
Posts: 479
Joined: Nov. 25, 2013

It’s a Monday on the North Shore

I’m excited as can be

I’ve been told that there is a package

And it’s just for me

I come around the corner

A brown box labeled SR Suntour is sitting on my porch

I am excited to see what’s inside

I almost light a torch (note to UPS – stop leaving shit on people’s doorsteps without a signature)

My wife and I put the kids to bed

I’m quivering with glee

It’s not for the potential for nookie (for once)

It’s for the fork in the box indeed-e-de

I open up the box

To see what’s waiting inside

I see a black 140mm beauty of the 29er variety

And I can’t tear away my eye (s)

It looks clean and crisp

With nice finishing aspects

I need to get it mounted on my bike

Am I ready yet?

The steerer tube’s too effin long

Kaboom goes my anticipation

I attempt to add a shitload of spacers

Because I need my mountain bike fixation

There is no star-nut included

Which tosses my emotions on edge

I am happy to see an extra volume spacer though

Which takes me away from the ledge

I step back to take a look

I can’t believe my eyes

My black beauty

No longer has a white demise (finished pictures to come)

Note: Dammit!  I can't get the spacing to work....anyway this may or may not be the last post done using poetry (only because I had fun writing it)…just don’t expect it herein.

Ok so what about the rest of the stuff?

Initial impressions:

The box left on the doorstep – Hey UPS, you’ve done this to me before and things have gone missing – stop being lazy and take it back to your warehouse or at least find a better hiding place.

I thought that the packaging would have more padding around the fork itself. It adequate, but for some reason, I was expecting bubble-wrap

  • The box included the fork itself, a manual (with CD-ROM), an extra volume spacer and a pair of SR Suntour socks (thank you - nice touch)
  • Note: the CD-ROM does not have this model of fork included – so no Auron-specific owners manual is included.

Nice finishing on the fork. The crown shape is clean, and I was happy to see that the typical mud-catcher stiffener bracket seen on the back of RS/Fox forks is not there. It seems to be a hollow piece of magnesium and is profiled – which looks pretty slick.

From the frontBack side

The black fork is glossy, and the decals are flush with the top-coat, which leads me to believe that the surrounding paint/clear process was sanded flush before a final layer, or the decals are painted on. Either way, it is well done, looks clean – my only complaint is that I can’t stealth-it, but that’s a personal preference (to at least have the option). Now a black-on-black Auron would be amazing (matte/gloss decals). The “brake-line attachment thingyTM” looks neat, however it does not attach with a bolt. It is hard to see from the pictures, but I’m worried that the plastic bracket will pop out while riding.

Brake line connection

Technical stuff:

The fork is within 100g of my Fox Float 34. When I chop off some of the steerer, I would guess that weight difference will be negligible. I did compare the axles and the QLOC system looks cool, but there is no weight savings. One cool thing is that you can put the lever on either side of the fork.

Its very hard to show how the QLOC actually works, but it seems slick - I'm not yet sure its any better/worse that those used by RS/Fox

There is more suspension adjustment on this fork than my Fox. Although I have not yet had a chance to ride it, there are a handful of aspects I can see may be a challenge to manage (adjustment-wise) trailside. The 5-stage HSC (lock-out to full open) looks nice but I’m worried that the mechanism may be tough to operate mid-ride while wearing gloves. The LSC has 17 different settings (vs 8 on my Fox), which could be amazing for those of us that never stop adjusting. The rebound knob is recessed (great idea) so it stays out of the way of harm, and has 25 settings, but it is a bit tough to get your fingers around and the “click” is not terribly audible.

Recessed knobs

I then pulled out my measuring device…aw crap - never mind, I couldn’t find a measuring tape. So, I used the next best thing:

New measurement technique

This puts the axle to crown measurement at 4 and 2/3 beer cans. This compares to 4 and ¾ beer cans for my Fox. And now that I have established a new unit of measure, I was able to confirm that the axle to crown measurement on the Auron is 1cm shorter than that of the Fox.

Side by side

Now when I take out my handy-dandy calculator and do some hardcore calculus…carry the one…give me a minute…Ok, I need to add a 1cm spacer below my stem to have the same bar to ground height. After I found my tape measure, I did confirm the beer-can measurement, and also discovered that the exposed stanchion between the Fox and Auron is the 1cm differential (160mm Fox, vs 150mm SR Suntour Auron – both 140mm travel).

Legal mumbo-jumbo to ensure you don't join the Fest series with this fork

I hope to get a good 10cm of steerer tube cut and a star-nut installed – then I’m off to the trails.



 Last edited by: Taz123 on July 11, 2017, 11:04 p.m., edited 4 times in total.
July 15, 2017, 10:10 p.m.
Posts: 1285
Joined: Nov. 21, 2002

A bit of an ordeal to track my fork down, thank you UPS for leaving the packing at 'met customer man', it would have helped if you delivered to the right street though. Luckily my neighbour was kind enough to complete delivery of my fork.

Initial impressions, my box was likely opened up by customs, or else UPS heavily abused the outer box. Luckily the contents inside were unharmed, despite the internal packaging not being the most robust. And I found no socks in my box, so somebody at customs is enjoying a nice fresh pair of SR Suntour socks :)

I've had the fork mounted up to my Rootdown BA, and I must say the all black fork transforms the aesthetics of my bike beautifully. Physically, the chassis is identical to my 2015 Auron RC2, down to the stickers on the sliders. I do not believe the crown has changed either. So really the only difference externally are the black stanchions. The angle of the pictures is deceiving; the new fork I'm reviewing on the right is indeed the same length axle to crown as my old fork on the left.

They say it's what's on the inside that counts. The new RC2 PCS damper (front) has less clicks of high speed compression (5) compared with my old RC2 (rear, something like 13), and the adjuster knob is definitely more difficult to turn compared to the old fork. On both forks, the low speed compression is adjusted with the smaller knob on the inside, and both the old and new fork appear to have the same number of clicks and ability to turn is the same.

On both forks the rebound adjuster is tucked out of harms way into the bottom of the sliders. As mentioned by another reviewer, this is a good protective feature however it does make getting to the knob a bit challenging. And the detents for the ~23 clicks of rebound adjustment on both forks are quite vague.

On the overall build/assembly quality, I won't be cracking the fork open to make sure it has been assembled properly. SR Suntour tells me that the fork I've received is no different than a fork that anybody else would purchase. SR Suntour doesn't run a oil bath in the lowers for lubrication as stock, they feel that users are more likely to regularly service the lowers and grease the seals if oil doesn't come pouring out of the lower legs; I do see that logic. Having said that, SR Suntour are also perfectly fine with a small amount of oil in the lowers for splash lube if that's the way you like to roll. Judging by the smear of grease residue on the stanchions after a few garage pushes and a quick rip up and down block, I can only assume that the seals have been judiciously greased and by extension the rest of the fork has been assembled properly.

I will report back once I've had a few hours on the bike and hopefully get the fork setup close to how my old Auron was. But the bike does look badass now with the black stanchions.

July 17, 2017, 12:09 p.m.
Posts: 36
Joined: Feb. 24, 2017

I think I'll go about my reviews with a weekly photo dump of my experiences which I'll continuously link and update. These can be found on my NSMB album here. Some of the photos I'll put directly in the forum, but more can be found through the link.

So I too received my fork last week, thankfully without delivery qualms. I won't go too far into detail of the unwrapping. The fork came in a standard box with an extra rubber volume spacer, aforementioned socks, and a how-to-sag support pamphlet + CD. I don't own a functional optical drive, so no comment on what's on that CD (2017 yo, a QR code would suffice).

The socks - 10/10 fit, excellent mid weight material, and an inspiring message about wrenching less and pedaling more. Fine, but I like wrenching too.

Initial out of the box impression - good looking fork! I tend to appreciate more subdued styles, but I don't mind the large and frequent AURON graphics. The lowers (magnesium) are a nice matte black while the stanchions and crown are a glossy black finish. The brake hose clamp is simply a plastic clip which feels like something I would break rather easily. The included Q-LOC2 axle is an elegant piece of hardware which allows for the axle cam to be placed on either side of the lowers. It seems almost unnecessarily complex (in design, not function) in contrast to a standard threaded axle system, but it works. Maybe it offsets machining costs of the lowers? I have no concerns about potential tire interference with a fender in the arch as clearance with the 29x2.4 DHRII is excellent.

I chopped my steerer tube to 195mm, pressed on a spare crown race and hammered a star nut in the steerer tube. I initially installed the fork on my XL Hightower and set sag to my go-to 25% which worked out to be 75ish psi (± analog shock pump uncertainty) and left the two pre-installed volume spacers as they were. These settings agreed with the online product manual recommendations for my 85kg riding weight.

During my initial backyard/street testing I noticed that the ~50mm of initial stroke was extremely sensitive. Playing with the LSC adjustment at either end of the 18 ( I think?) clicks left me feeling like there was actually very little damping input. A backyard test is by no means a proper way to dial in damper, however the difference between fully open and fully closed was less noticeable than I had expected. To compensate for the stroke sensitivity, I set the LSC to 9 back from full closed, and HSC at 1/5 (full open)

The rebound knob is tucked away in the lowers and allows for 26 clicks of adjustment (again, very hard to actually feel these 'clicks', but I'll chalk that up to the new-fork-feel for now). I settled with 9 clicks back from full closed.

Other suspension companies often include "factory baseline" settings, however after searching online and in the provided literature I didn't see any recommended start points. I'll be interested to read the settings of other reviewers.

On Sunday (July 16) I was able to get out for a quick initial shakedown ride in Bellingham, WA on a 25km loop with 1000m of climbing in the Blanchard Mountain area. The trails are on the mellow end of the PNW difficulty spectrum, however there are a few gems to be found with optional jumps and high speed (short lived) rock gardens. For the most part, the area provides fast and flowy descents with relatively straightforward single track climbs.

Immediately when pedaling I increased LSC damping to three clicks from closed and was happy with that position for the remainder of the ride. I left the HSC open at 1 for the day expecting to increase it as needed, however due to the nature of the trails I was not in a position to observe the effects of changing the HSC. My biggest ask of the fork was about a meter drop which felt very supported, using only ~90% of the travel. Overall the fork felt great, and I'm looking forward to more demanding rides in the coming days, dialing in my settings, and reading how the other testers are setting up their fork.

 Last edited by: jan on July 17, 2017, 12:12 p.m., edited 1 time in total.
July 18, 2017, 12:12 p.m.
Posts: 479
Joined: Nov. 25, 2013

My black-beauty was taken for its maiden voyage on Sunday evening.

As reviewers, we had been provided a bit of info from SR Suntour on set-up. Essentially, we needed to keep the pressure below 90 psi, otherwise the negative spring would pull the fork down into its travel. So, after setting the sag to 85 psi (equating to ~28% sag...which is a bit much), and putting the LSC/Rebound at middle-of the range, I decided to giver a go.

I thought that a quick lap of a local trail that has a bit of everything (John Deer) was in order. Its got some flow, some jumps, and a handful of rocks...and when you go "mach-chicken" (I giggle every time I see or write this phrase) through those rocks, you can exercise a fork pretty well.

Within the first few turns, I knew I had the fork set too soft. And after the first jump, I had tested its full travel. I cranked up the HSC and LSC a few clicks and the fork stayed a bit higher. The rest of the ride was good, still a bit too soft.  I played with the HSC setting a bit more, but didn't notice much of a change in the behavior of the fork. I think this may have been due to my running more sag than normal. The fork is loud as the rebound circuit kind of like when Slimer from the Ghostbusters movies goes through a wall - that squish sound. It doesn't seem to impact performance , just something I noticed.

Decision time - so I took the fork (and supplied volume spacer) to my LBS (Dave @ Bicycle Hub) and installed the extra spacer. If I had a 27mm bit at home, I would have done this myself. The installation was terribly simple - bleed the pressure, un-screw the cap and snap on another spacer. I now have 3, and the max is 4. The one thing of note is that the fork dove into its travel as the air pressure was removed. This required us to haul on the crown/wheel to get the negative spring to re-seat. I've not had to do this on my Fox 34, so it caught me a bit off-guard. Going forward, my thought is that I can run a bit lower pressure and get better support from the fork as I use up the travel. If this doesn't feel right - the next step is to go visit Suspension Werx in North Vancouver (SR Suntour's certified service center) and have a new/larger negative spring installed designed for the full-bodied or aggressive-riding individual.

I plan to ride tomorrow and Thursday night (Fiver) to give the fork a "race-pace" test (or at least my version of "race-pace").

The all black looks pretty awesome. My lowers seem to be of the "gloss" or "shiny" variety.

Stay tuned...


July 22, 2017, 12:28 a.m.
Posts: 36
Joined: Feb. 24, 2017

I'm out in the Rockys with the Auron mounted to my Chromag Surface. I'm still in the process of dialing in my suspension settings, without yet finding my sweet spot in the tune. While I've been enjoying the fork in its general all-around performance (more on this in another post), I am really struggling to use the full travel. I dropped my pressure to 65psi from 75psi, which sat at 30% sag (up from my initial 25% sag). 30% sag felt like the fork was sitting too low after an initial test so I went up to 70psi. Sitting now around 27% seated sag, I'm still having trouble realizing all 150mm. In my efforts of achieving a good suspension feel, I always feel most confident with my settings after going through an iterative bracketing process of assessing my options, akin to Newton's method

My philosophy is that while I shouldn't be bottoming out the fork frequently, in some applications I would expect myself to reach that travel.  Recently in the Kananaskis area on a particularly rough section of trail full of imposing rocks and roots on a steep and extended alpine descent, I tried riding "through" the chunder in contrast to my usual (attempted?) style of a more selective line choice and riding "above" the rough. I was by no means riding slow, but still managed to never use more than 140mm of travel, even with LSC/HSC fully open. 

At this point, I'm considering going the opposite direction of Gord and removing a volume spacer from the air spring just to appease my curiosity. On paper I would expect myself to be achieving full travel with an open damper at 25% sag while thrashing around at high speed. However since this is in fact a review, I'll assess the fork with a less progressive air curve and report back with my findings. Until I find a chamferless socket on my travels in the Rockys, I'll continue investigating lower air pressures with a greater reliance on the damper.

I'm looking forward to hearing what other reviewers are experiencing with their fork settings and respective riding weights.

July 22, 2017, 9:40 a.m.
Posts: 1285
Joined: Nov. 21, 2002

I'm 180 lbs geared up. Currently on 70psi. All damper adjusters in the middle to start off with. I think I can speed up the rebound a few clicks and also back off the high speed compression.

It feels a bit smoother than my old Auron. From the stroke support standpoint I haven't noticed much difference yet, but blowing through the travel hasn't been a problem at all with the 2 spacers currently installed

July 30, 2017, 8:03 a.m.
Posts: 479
Joined: Nov. 25, 2013

I'm getting closer on setting this fork up to be mint.

I've been riding it at the max recommended pressure of 90 psi for the past week - not because of sag, but I was still diving through travel. I've gotten close by increasing LSC/HSC, but I still don't feel as supported as I would like. This was quite apparent while racing the Fiver last week - in other words, the fork packed down a bit at speed. Overall, the fork is still stiff, no creaking and supple off the top. I'm also happy to report that the "brake line attachment clip" has not come undone or loose...and the black stancions are awesome.

In an effort to tune things up, I contacted Dan at SR Suntour and he agreed that I should look at making a change to the fork internals. I had two options, go see Suspension Werx in North Van, or do it myself...of course I wanted to tinker myself, so I chose the latter option.

After a few short days, a new negative spring assembly and volume spacer arrived. Dan's recommendation was to install both the spring and another volume spacer and start at 105 psi to see how that works - I may only make one change at a time, but we'll see. The tech videos on the SR Suntour website look very comprehensive (sorry, I can't get the link to embed - its the first hit on google), so I am encouraged that most garage mechanics can handle this. Now to test this theory first-hand. 

Installing the spring is today's job, and I hope to get out for a quick rip to test it out (pics and a report to come).


Aug. 2, 2017, 4:09 p.m.
Posts: 36
Joined: Feb. 24, 2017

I have returned from my trip to the Rockies having racked up some substantial hours with the Auron on my Chromag Surface. I had a taste of Revelstoke, Kananaskis, Canmore, Bragg Creek, Fernie, and Rossland which totaled around 300km and 7000m of climbing (/pushing). Overall I am quite pleased with the performance and support of the fork. I'll agree with Gord that the noise of the rebound circuit makes for one of the loudest forks I have ridden, with the majority of my riding still at 9 clicks back from fully closed on the rebound.  The 34mm stanchions are plenty stiff for my purposes. The steerer tube, obviously still quite new, hasn't made a peep or creek. And I'm really enjoying the use of SR Suntour's proprietary axle Q-LOC2. Looking for a "backcountry epic" ride in Fernie, BC, my friend and I found ourselves on the Mountain Lakes backcountry route through the Three Sister's Wilderness area. The all day route required a fair amount of bicycle-portage and bushwhacking, however I was happy to see the Auron come away from the affair unscathed. 

The initial stroke is relatively supple and the mid stroke support is very supportive, too supportive in my case. Only during one specific huck to flat did my travel o-ring indicate that I had come within 2mm of the full 150mm fork travel. For the most part, my maximum travel used on the trail topped out around 140mm. Glancing at my stanchions after finishing my Seven Summits ride in Rossland, BC, I thought gave a good summary of my travel history. 

My initial impressions left me playing around with the air pressure so much that I was pushing 30% sag (the upper recommended limit of SR Suntour) to actually use the full suspension travel. Without access to a 27mm socket on my travels, I was stuck riding with the 2 air volume spacers. I'm back now and have removed one volume spacer from the air spring top cap. Aside from finding a 27mm socket and grinding down the edges (I'll never touch a fork with an adjustable wrench, no matter the occasion), the process was very simple. 

I downloaded the manual from the SR Suntour website and noted an 85psi suggested pressure for my 85kg rider weight. Also noteworthy is the manual chart nomenclature of "Aggressive", "Balanced", or "Easy" to signify the level of exponentiation of the air spring curve. I guess I like it 'Easy'? 

With my Auron back on my Santa Cruz Hightower, I pumped in the suggested 85 psi resulting in 26mm of seated sag, or just over 17%. Not great. I reduced the pressure to 80 psi which measured 20% sag and went ahead there with my starting point. 

To some extent I recognize that my comparison of the Auron on the hardtail vs full suspension bike are not entirely equal. Hardtail riders certainly weight their forks differently while riding, relying on a supple early stroke for traction and a relatively more progressive spring-ramp to account for changing bike geometry and greater load demands. That said, having experienced the fork on my hardtail with a spring rate more progressive than I felt necessary for my performance demands (or preferences?), I'll be interested to see how the fork performs back on my hardtail with a less progressive spring curve, and if the compression damping circuits can provide a meaningful difference when mounted between the full suspension/hardtail.

So now I've got just a few rides in on the fork since removing a volume spacer, however I'm already noticing the fork riding further up in the travel even at 20% sag. I'm yet to bottom out, but I'm more comfortable with my travel use up to 145mm regularly on larger drops and faster chunder sections of trail. My rebound adjustments have not changed, however I've been running both LSC and HSC fully open. 

While most of my experiences thus far have been overshadowed by managing the spring progression and air pressure, I've found the sensitivity of the LSC and HSC settings to be relatively limited - i.e. the feel of the fork betweenLSC/HSC  full open and fully closed does not have a drastic change on the performance of the fork. This is something I'll explore more in the coming week as I continue to suss out the Auron's capabilities.

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