Forum Testing: Suntour Auron 34 RC2 PCS

Gametime

For those that have read my previous posts, I have been struggling with getting my test fork – SR Suntour Auron 34 set up just perfect.

Since I’m watching a Blue-Jays game while writing this, I thought I would write this as an interview or maybe a back and forth banter with a play-by-play TV announcer – I dunno, lets see how this turns out:

Gord: “It was a beautiful night in North Vancouver when I realized that I had maxed out both the HSC and LSC on my fork, had it at the max recommended 90 psi and still felt like I was dropping through travel.”

Gord: “Before the game, I had had a conversation with Dan (SR Suntour Rep) about my options. He was honest and straightforward with recommendations (unlike other coaches and managers I speak with). He could have said that I could crank up the HSC/LSC and then tell me that I was either too much of a fat-ass or rode “too aggressively” for an AM fork and I should perhaps get a dual-crown or “enduro-up”.  Have you had anything similar happen Taz?”

Taz: “I have Gord. I have been using a certain a certain fitness tracker for the past few years. The tracker is to be used when eating, sleeping, working out…but not showering and swimming. I discovered some bubbling below the rubber strap, so I contacted their warranty department. The response was that since I had sweat whilst using my fitness tracker, they could not warranty the unit. This was frustrating since the tracker is designed for fitness…which would imply the presence of sweat”

Gord: “Oh my Taz, that is frustrating. Now what does that have to do with mountain bike forks?”

Taz: “Nothing Gord, I just thought it was a good story indicating how some companies stand behind their products and others play ‘fine-print-butthead’”.

Gord: “Ok, well back on track, Dan offered to have me send the fork in to Suspension Werx to have a new negative spring installed – his thought was that if I added the larger negative combined with another volume spacer, I would be able to get the required support, but also have the small bump compliance that I desired”

Taz: “Interesting Gord, but you know your way around a workbench, so wouldn’t that be a pain in the ass to not only remove the fork, but find time to connect with another shop? Obviously you would have to remove yourself from the starting roster and put yourself on the DL”

Gord: “It was, so Dan indicated that he could send me the required spring, and a link to some videos as to how to make the swap. It was an interesting game-plan that would minimize downtime and allow me to add value back to the team.”

Taz: “Well that was a helpful alternative. I can assume that the installation could still be handled by your ham-fistedness”

Gord: “Now Taz, no need to be an arse about it. I may be 0 for whatever with getting the fork set up perfectly, but being a good teammate means supporting me through the challenging times. Yes the videos were simple (http://www.srsuntour-cycling.com/service/tech-videos/), and even without the “perfect” tool, I could get the fork dismantled and make the swap”

Gord: “I first removed all the air from the fork because dismantling the pressure boundary whist the unit is under-pressure is kind of a bad idea”

Taz: “Hahahaha, I could only imagine the kaboom of parts and oil all over your garage”

Gord: “There is no oil in this fork Taz, so I first removed the top-cap and added a 4th (and final) volume spacer. It was simple as the spacer just clicked into the existing stack of three”

Taz: “I do agree that this style with spacers is so much better than having to add/remove oil from the bath, or trim a fixed spacer to tune the fork progression”

Gord: “So now you decide to agree with me on something…Anyway, the air cap removal, spacer click-in and re-installation was smooth as silk. I then tackled the bottom of the fork. I can sometimes be a little lazy…”

Taz: “Just like a…”

Gord: “Shut-up Taz. Anyway I decided to see if I could make this swap without removing the fork from the bike. I pulled off the rebound cap, removed the o-ring and started to remove the nut. I was a bit surprised to have a pocket of air let go. It made me jump a bit”

Taz: “Wuss…”

Gord: “Sometimes, I just wanna…woooosssaaa…ok so I then moved to the air-side and pulled off the lowers. I immediately noticed that the air-size shaft pulled back into the stanchion a bit (which makes sense since it’s a negative spring). I looked at the old/new springs together and noticed that the new spring was longer. I also noticed the black spring travel spacer…this got me thinking that I could lengthen/shorten this fork by adding/removing these spacers…oh fun for future”

Taz: “That is a nice alternative. It saves having to buy alternate internals or heaven-forbid a new fork.”

Gord: “So I followed the videos and pulled out the old spring and pushed the new one in. After tightening up the lock-nut, I put the lowers back on. I did notice that lowers had to be pushed almost the whole way through its travel to get the lower nut installed. Taz, have you seen this happen before with those other fork manufacturers that both rhyme with rox”

Crescent wrench to remove the old spring

Length different

Compressed without air.

Taz: “No I haven’t Gord, but as long as you get back to full travel once the fork is aired-up and you don’t sacrifice travel, it should be fine.”

Gord: “I agree, I have not yet had the chance to give it a trail-test, but at 110 psi (and 20% sag) it feels more supported than it did before as I bounced around my street.”

Taz: “Wait a sec, you’re telling me that you’ve been talking for the last 5 minutes and didn’t even give it a trail test?!? Jeez Gord…”

Gord: “Now Taz, ease of maintenance is a very important part of this review. Things have been a bit nutty lately, and I’m out of town for 2 weeks, so a test will have to wait until after the all-star break”

Taz: “Ok, lets get back to the game. This broadcast has been brought to you by “John’s VCR repair” – With the unreliability of the internet, Netflix is a thing of the past. VCR tapes are making a comeback – if you need your VCR player fixed, look no further than John’s VCR repair located in a van down by the river…”

Next level, Gord. I mean Taz.

It has been just over a week since we got home from our cross-country vacation. I think I'm still tired or at least jetlagged - 4 provinces, 8 cities and 7 different beds over 2 weeks...zzzzz

Anyway, I have gotten out on the new spring for a few rides and am very pleased with how the fork rides with both the new negative spring as well as an extra volume spacer. I'm getting quite a bit more support through the travel, am not bottoming out anymore and have been able to dial back the LSC/HSC. Realistically, I need some more time on the fork playing with settings (and likely dropping the air pressure down a bit) to get it tuned with more suppleness off the top, but I think I'm pretty close.

The next debate will be whether I add the final available 10mm of travel and see if behavior changes... but for now, I really want to get this set-up dialed first.

I've also hit the dirt a few times - overall the finish on the lowers is holding up well to wear and tear. No marks on the stanchions, and the wipers are doing a good job managing the copious amount of talcum powder (I mean dust) that are around the trails and ultimately coating everything.

-Gord

A quick update from the island. 

I, unfortunately, have not had much time on the fork this summer as I have been plagued with sickness and injuries. I did get some great rides in on it in Cumberland though....everything from climbing logging roads to descending steep and nasty dry, dusty rooty trails. My big takeaway from that weekend was how much the Auron made me feel I need to upgrade my rear shock, it just felt good!

I actually had to put more air in it than recommended because of my weight (270 lbs) but it is still the most supple feeling fork I have ridden in years....and unlike my Xfusion Trace I came off of I am able to use all the travel. 

I need a bunch more time on this fork to get the settings right, and I think a conversation with Dan at SR Suntour about the negative spring and spacers...so I will have another update soon about that.

Time to post my updates as well from the past month or so.

I haven't had the same amount of trouble with setting the fork up to my liking that other testers have so far. Having said that, I'm a fairly 'basic' user and not much of a tinkerer when it comes to suspension performance and behaviour. Once the seals and bushings worked in (about 4 hours of riding), the fork was even more supple than new, very happy with this. I'm just running the stock greased seals, no splash bath added to the seals and lowers.

Air pressure: easy to dial in. I have sag set at 30% with the 2 volume spacers installed 

Rebound: easy to dial in.

LSC: I'm pretty happy with the middle setting. Fork seems well supported during steep downs and braking, I don't do a ton of flattish gravel road climbing so no comment there. Fork remains supple enough with low speed steep techy climbing

HSC: down to the 1st (minimal setting) click. Fork feels good on faster/harder hits for me, I'm able to use the full travel without any significant or obvious bottoming out. I think this setting works well for me and my style with the 2 installed volume spacers

I was really hoping to take the Rootdown and this fork to Whistler and get some easy repeat runs to try and play around the tuning myself. But being late season after Crankworx, the trails and berms were bombed out and I realized my body wouldn't take the 2 days of pounding on a hardtail. Maybe towards the end of the bike park season I'll try to sneak up for a day with the Rootdown.

Versus my older Auron without the PCS, I can't say I notice much if any difference in the damper -- aside from the compression knobs being more difficult on my fingers with the newer fork. The fork's stroke IS smoother though, and the fork is more responsive IMO.

Just wanted throw this action shot up here, my good riding buddy snapped a few for me. The fork has been working really solid for me, its a great feeling when everything on the bike just seems to come together and everything just works. The bike as a sum of its parts has really helped me explore and push my boundaries, I'm not usually one to enjoy getting my wheels much off the ground, but I can say that the fork's support and control has afforded me an additional level of predictability and confidence.

Now I've not spent much meaningful time on a Pike or 34, but this rendition of the Auron does not leave me wanting much more. It's not a night and day difference versus my old Auron, and the exact difference is hard to quantify for me, but I know it's there and I know I ride things now that I didn't bother attempting even 6 months ago. I've been riding a long time, so I don't think this comes down to discovering a new part of the learning curve for me either.

I finally took the forks apart and put in a heavier negative spring the other day and I found it to be super simple (my first time opening a fork up). I just had to go buy a 27mm socket and the rest was easy! See Taz123's awesome post above for pictures of the new negative spring install.

I also put 4 volume spacers in when I put the heavier negative spring in. When I told this to Dan (Our SR Suntour Rep) he said that he thinks I don't need that many spacers, but I am fairly headstrong and like to learn the hard way. Lo and behold on my first ride out on the new setup, I was not able to get full travel out of the forks. The great thing about the spacers is that it takes about two minutes to let the air out and open up the Auron's to change up the tokens. After taking 2 out I was getting full travel back and feeling plush!

Being a bigger guy I usually feel like I lose a lot of the initial stroke plushness because I have to put so much air in my forks...but I have been really surprised at how plush these forks feel. The Auron feels so good it makes me feel like I need to do something with my rear suspension.

After riding this fork for a few months I have been impressed by how plush and supportive the SR Suntour Auron RC2 PCS forks have been. Not having to buy expensive specialized tools to work on them was a treat too. The amazing support from Dan even during the busy bike show season was amazing, most bike industry types tend to go dark over the crazy season, very good support!

There are a few things I would like to see changed though. The first is that the compression adjustments do not offer much actual change in feeling even between 0 and full on. The second being the compression noise, I prefer my forks to be silent unless something is wrong. Other than that, these are some great forks.

While they are not the most advanced, lightest or blingy-est (is that even a word?) out there, the Auron RC2 PCS offers a great bang for the buck fork that are easy to work on, bombproof, plush and I think great looking (love the black stanchions). If you are in the market for a lower cost fork that will be troublefree, this is the fork for you!

First off – thank you to NSMB.com and SR Suntour for providing the opportunity for forum members to review some product. The Auron is a great mid-range fork. I think it competes well with the Fox 34, but is still a bit behind in some design aspects. From what I gather, my issues/concerns noted are taken care of with the new Durolox R2C2 fork.

Taz: Gord…Gord…where the hell is that guy?

Gord: What’s up, I just got back from a ride

Taz: So I had a bituvan idea…I started tinkering wiff the fork and tried a few things

Gord: You are slurring a bit bud…

Taz: So I had a few drinks as I was workin the fork…so sue me you putz. Anyways I decided that to make the 120mm rear travel Transition Bandit 29er….hehehe “Bandit” Pow-Pow stick-em-up…get it? Shut-up.

Gord: Oh boy, what did you do?

Taz: Is ok, is ok, is ok. The bike is designed around a 140mm fork. So that’s where we have been testing the fork thus far – 140mm, 4 volume spacers and the stiffer negative spring for our fat asses. Its been ok, but I can’t get it use full travels and it felt hard on my hands after a long-downhill.

Gord: Put the beer down and finish the story first…wait a sec, PBR? Ugh ok pass me one

Taz: So I had a brain epiphany…or brain wave…or whatever, is a good idea I swear – Seriously! I thought that 150mm is just a bit longer than 140mm…and more travel is always better, so les make it longer and what could possibly go wrong?

Gord: Ok so I follow so far…and I do follow your drunken logic. With the lower axle to crown height vs the fox 34, you do have 10mm of room to keep the head angle and BB at the same height and gain an extra 10mm of travel…tell me what could go wrong?

Taz: Thiz fork is soo easy to take apart. Remember the pics we took earlier, you just bleed some air, uses a sockets wrench (not that imperial crap, a 10mil freakin socket) and the lowers pop off – no oils or messes! I pulled out the negative air spring and then had to do some concentrating…do I remove or add spacers to get more travel…so I tried both…and then got more confused…and then texted Dan from SR Sutour and he helped me out…then I had more beers.

Gord: So what did you do in the end?

Taz: I created a freakin pogo stick. Here was the test - 150mm travel, lighter negative spring (200lbs and under) and 4 volume spacers. It was not the best of ideas… I was bouncing around all over the trail and struggled with climbing (keeping the front tire down). So don’t do this.

Gord: Ok we learned something then. So here is where I landed with tuning on my fork. I also struggled with not getting full travel and the fork was unforgiving. I kept the fork at 140mm, I also kept the larger negative spring in. I took one air spacer out and played with the LSC a bit and voila! Full travel! I think there is a bit of room to play with LSC more to make it prime (HSC doesn’t seem to do much and the knob needs a re-design to be easier to use with gloves on).

Taz: show off…

Gord:  It is still loud though as it works through travel. Minor complaint, but it is there. It rains a lot here, did you mount a fender yet?

Taz: a real mans wears googles…or goggles or whatever. Never go full Enduro!

Gord: So that’s a no. I bought an “ass-savers” zip-tie-mount one to see how it fits. Clearance with a 2.35” width Magic Mary was tight. On the first ride, it buzzed all over. After the ride, I did some “trimming” of the fender and added a few extra zip-ties to pull the fender closer to the arc. Much, much better. I think SR Suntour is onto something with the fender that is included and attaches directly to the Durolox. The modern rider tries to not let weather hold them back, so as long as the Durolox allows for clearance with larger volume tires or big knobs…sounds like a win.

Taz: I need another beer

Gord: Overall this was a great test – we tried a lot of different configurations and am very impressed with the ease of maintainability and tuning options for the DIY mechanic. The overall finish is good, but I would like to see the HSC knob design changed and the HSC circuit needs a bit of work to make a more marked change in how the fork behaves. Volume spacer pucks are easy to use and are better than the older version, which required the spacer to be trimmed.  

Time to go ride!

It’s been about six months since installing the SR Suntour AURON RC2 PCS. In my last post I was having some struggles getting the fork to perform to my liking. After reducing the pressure to about 73psi, running a single air spring token and fine tuning the low speed compression, I was happy with my setup. Having dialed in the progressiveness of the fork to my liking, I wasn’t too concerned with the high speed compression and left it open at 1. 

I initially installed the fork on my hardtail where I briefly tried using the fork with a 27.5 x 3.0 Surly Dirt Wizard, however the clearance was simply not there to accomodate a plus sized tire. Fair enough, that is well outside of the design parameters of the AURON. For the remainder of the test I ran this setup on my Santa Cruz Hightower in conjunction with a CC DB Coil IL with 29 x 2.4 wheels. Since installing the AURON, I’ve racked up about 2000km of riding and feel comfortable reporting on it.

The 29er setup traveled with me on a trip back home to Colorado. During that time I was able to revisit the trails where I learned how to mountain bike in the Front Range. For the most part, these trails consist of casual XC single track with a rock garden or two strewn about. From sprinting through smooth singletrack to navigating chunder through a rock garden, the AURON felt balanced and poised with whatever you might throw at it. It was in the rock gardens however that I really noticed how noisy the fork can be during the rebound stroke. While not exactly detrimental to the performance, I did find it a bit distracting while focusing on line choice / keeping it rubber side down. 

I tacked on an extra week of my trip in Colorado to join some friends in bike packing through the San Juan mountains from Lake City to Durango on the Colorado Trail. I  borrowed what gear I could from friends, strapped it to my bike and got going. Over 5 days we covered about 200 km and 10,000m of elevation gain. With the added weight of the loaded bike, I increased the air pressure 10 psi and and left the single air volume spacer alone. Though bikepacking often implies much slower riding than one might consider during a normal day ride, the added weight of the gear was a great way to test the fork under technical descents. At the end of the trip, there wasn’t a time where I had experienced noticeable flex in the fork, brake dive, or really any reduced performance whatsoever. 

Following a summer of adventures in the Canadian and US Rockies, I was happy to be back in the Northwest and soak up as much fall riding as I could. I’ve been riding several times a week on my favorite local spots, mostly around Mt Seymour in North Vancouver and in Sudden Valley area of Bellingham. The one area of the fork that I had yet to really feel confident about was the high speed compression damping. The AURON offers 5 adjustment settings, however I wasn’t sure I had ever made use of the feature. There was one trail I knew I could reliably bottom out my fork on (the final drop on Ned’s), so I took to some suspension bracketing to try and make sense of the damper. A series of jumps later, I still could not personally feel a difference between the performance of the fork with HSC fully closed or fully open. In comparison to other forks with high speed compression circuits, I think this is the most obvious area of reduced performance when considering the SR SUNTOUR AURON.

To date, my fork stills feels as plush as the day I first installed it. That’s great, but is also a bit of a shame as I was hoping I would have been motivated to open it up to change the seals and oil. From a look at the online service videos, there seems to be quite a bit of information available, however it’s rather poorly organized. You have to really know what you are looking for in order to get at the info. The product manuals don’t exactly help in that department either, as they seem to feature outdated models in current manuals, or more deluxe dampers that are unavailable in your chassis (i.e. why talk about R2C2 if it’s not available in this generation of the AURON chassis?)

Overall I am incredibly impressed with the fork. Once setup, it offers an impressive range of adjustability of the low speed compression and rebound circuits which provides incredible amount of traction and support for aggressive riding. As I’m left wanting a bit more out of the high speed compression damping, there are a few other noteworthy issues that are worth discussing. For one, the brake hose clamp is pretty flimsy and I’m sure I’ll crack it one of these days. It would perhaps be advantageous to offer a threaded solution. While impressively designed, the Q LOC 2 axle system isn’t as set-it and forget-it as a tried-and-true threaded axle. I experienced improper installation of the axle twice due to improper preloading of the collet; once by myself, and once by a friend putting my wheel back on. It’s a simply and easy system, and an impressive way to save machining costs and weight on the lowers, but it’s not idiot proof and for being a component so paramount to system safety, it really should be.

In a time where suspension companies release new products faster than Apple releases iPhones, the AURON is a great option for those who want to think outside the RockFox. Riders looking to trim extra seconds off their stage descents and inflate their strava fueled egos will find more tunable options to support their lifestyle, however I think the SR Suntour AURON 34 is a great option for the vast majority of the mountain biking community. It was impressive enough for me to sell my 36 RC2. 

Super duper thanks to everyone at NSMB and SR Suntour who allowed us laypeople take part in such a neat product test. I hope we were able to help you achieve what you had envisioned from this forum-testing base. 

TLDR

Positives

• Sleek design, despite not being one of the ‘big guys’ in the suspension scene

• Ease of user serviceability

• Adjustable air spring volume 

• Relatively light for its market category

• Impressively stiff 

• Excellent traction and support throughout the stroke

Negatives

• Noisy rebound strokes

• compression adjustment knob could be more ergonomically designed

• Lackluster high speed compression performance

• Very progressive air spring could be tricky for lighter riders

• Axle should be idiot proof

• Service information could use some organizing

Time to post the conclusion of my review. To jog memory, I am coming from the previous Auron 34 RC2, though I only really had about 4 months on that fork. 

The fork I was provided to review has the same chassis, down to the 34mm stanchions, with the only external difference being the black stanchions. The only other difference on the outside was a different high speed compression knob, with the one on this newer PCS Auron definitely less finger friendly compared to the one on my old fork. 

I'm a novice rider, a tinkerer, but don't generally like to crack open suspension. 

Unlike the other reviewers, I found the fork fairly easy to setup and working well. It could be that I'm more easily satisfied with my fork settings. Through the testing period, I did not find the fork bottomed harshly when I used up the full 150mm travel on my 29 fork. Most of the times I would be using ~140mm of travel, and only on big (for me) hits/screwups was the full 150mm used up. Pretty close to ideal settings in my book. 

I found the fork to move into its travel very nicely after the first ~2 hours of riding, and it remains nice and plush today with no maintenance to the lowers/seals. I didn't find the fork too divey with the low speed compression dialed back 3 clicks from the middle. The fork moved through it's supportive midstroke quite well, I can't say that I noticed any 'spiking' on repeated hits. I found the low speed compression and rebound adjustments to be in a good useable range for me, the range is definitely not as wide as other forks on the market. I often wonder what is the point of having the rebound adjustable to slow that it takes 5+ seconds to fully extend back to full travel. I too found that the high speed compression didn't seem to make very much difference at either spectrum, I just left mine wide open. That is not to say this was detrimental, as I was happy with the fork's performance regardless of where the high speed compression was set.

I personally wasn't bothered at all by the little bit of noise that all reviewers seem to love mentioning about SR Suntour's products. I haven't had extensive experience on competing Fox or Rock Shox products mind you, however my Marzocchi RC3 forks are definitely louder.

When it comes time to pull the lowers to do some maintenance, this is probably something I'll tackle on my own seeming as though the fork appears to be quite simple in this regard. 

It looks like the newer boost versions of the Auron are now upgraded to the 35mm stanchions so that should also offer some additional stoutness for those who are looking to boost-up. The 35mm forks also fit the nice integrated bolt-on fender that SR Suntour offers now.

tl;dr would recommend this fork if your rider profile is similar to mine

We would like to thank all of the testers involved.   It takes time and we appreciate all being apart and giving honest feedback.     As part of our thank you each tester will keep their fork and continue to beat on it.   Cheers and happy Trails.    #perceptionchanging