SR Suntour Epicon-X1 LO-RC 26 Fork

(discontinued)

Review by Evan Turpen // Photos by Brandon Turman

SR Suntour has been making a steady and consistent push into the high-performance suspension market. More recently they’ve introduced many products with a plethora of advanced adjustments and features similar to what can be found on the other leading suspension manufacturers.

Our test fork, the EPICON-X1 LO-RC, came with external low-speed compression, rebound, lockout, and air pressure adjustments, as well as internal travel and air volume adjustments. These are all features that are nice to see, especially on an all-mountain/cross-country fork that retails for $599. Additional upgrades to the EPICON-X1 platform are available in the form of an external travel adjust and remote lockout.

The 32mm chassis looks clean, refined, and fit for the task although not as flashy as the others it’s targeted to compete with. The adjustment knobs are simple and easy to turn with defined clicks and smooth operation. With all signs pointing towards a successful product, we installed the fork on our test bike and gave it a go. Read on to see if the fork held its own in this extremely competitive market.

Epicon-X1 LO-RC Highlights

• Available in 26 or 29-inch wheel options
• 32mm stanchions
• 26-inch 150/140/130/120/100mm travel
• 29-inch 120/100mm travel
• External rebound, low-speed compression, lockout, and air pressure adjustments
• Internal travel and air volume adjustments
• QSP (Quick Service Product) sealed hydraulic cartridge damper
• Progressive air spring system (can be adjusted internally more linear if desired)
• Magnesium lowers
• Forged hollow alloy crown
• Alloy steerer (tapered 1.5 to 1-1/8-inch or straight 1-1/8-inch)
• Integrated brake cable guide
• 15mm Q-LOC axle or 9mm QR
• Disc post mount for 160mm rotors
• 1,785g / 3.9-pounds (26-inch 150/140mm option, full-length tapered steerer with 15mm axle)
• Available in black or white
• MSRP $599

Setup

Installing our Epicon-X1 fork was a mostly simple affair. We measured and cut the steerer tube, installed the star-nut and crown race, bolted up the fork, mounted the brake and routed the hose through the guide. The 15mm Q-LOC axle threw us a curve ball though in our otherwise simple setup. It can be a little bit tricky at first to install and remove (at least until you get the hang of it). The axle has a unique collet design that has to be seen to be explained. It also requires a smooth continuous bore on your hub axle. Hubs with lips or ridges inside where the 15mm axle slides through cannot be used, at least with this version of the Q-LOC system. SR Suntour noticed this issue with their design and is now shipping their forks with an updated Q-LOC2 axle. The new axle is compatible with all 15mm hubs and should allow for some of the fastest install/removal of all known thru-axle systems. Once everything was successfully installed, we simply set the air pressure, rebound, and low-speed compression to our tastes and we were pleasantly surprised by the ease of adjustments.

On The Trail

The Epicon-X1 fork has a smooth feeling right out of the box without any real break-in period to achieve this. In the stock setting the air spring has a fairly sensitive feeling off the top of the stroke, better support in the mid-stroke than most of its competitors, but a little bit too much ramp for our tastes towards the end of the stroke. Fortunately SR Suntour included a simple foam air volume spacer attached under the air cap which can simply be removed or cut down to achieve your desired levels of ramp. We experimented with the spacer fully removed and this allowed for a very linear coil like feel. We applaud SR Suntour for including this adjustment as it will most definitely allow picky riders to further dial in the fork to their tastes.

Stiffness of the chassis is actually quite good for a 32mm fork with no complaints here. The fork also functioned for the entirety of our test with no creaks developing in the crowns (a problem that plagues many 32mm forks).

The adjustment range of the QSP hydraulic cartridge is very noticeable and effective. The lockout is very firm and the lever moves smoothly from open to locked. The rebound range is good as well. We were able to easily find a setting that we were comfortable with. Sometimes we find ourselves being between adjustment “clicks” on other brands forks, but not with the Suntour. The low-speed compression also worked very well with an excellent adjustment range making it easy to find our setting.

The EPICON-X1 absorbs hits with the best of the best 32mm forks. We never experienced any harshness or “spiking” even when set to a firmer compression setting. We did, however, notice a bit of noise coming from the rebound circuit, especially when getting airborne and the fork extended from deep in the travel to full extension. Despite the noise, the rebound characteristics were very desirable with the fork recovering from successive hits well, yet remaining stable on the bigger hits, g-outs, and landings.

Things That Could Be Improved

Travel Adjust: The internal travel adjustment requires a drift punch and a careful hand to reset the travel through repositioning the negative spring assembly. Snap on spacers to reduce or extend the travel would allow for a much faster change and stick with the “Quick Service Product” theme.

Axle: Our 15mm Q-LOC axle became nearly impossible to remove at one point because the expanding collet system would hang up on the lip between the dropout and the hub. Luckily this is an issue that Suntour has already addressed and all EPICON forks now ship with the much improved Q-LOC2 axle.

Seals: Throughout our test our seals continually wept lubrication in small amounts. The seal design seemed strange in that the seals lip angled down and in where it contacted the stanchion tube. Although smooth, these seals seemed to allow excessive lubrication to escape. Surprisingly though when we took the fork apart at the conclusion of our test, the seals had done a great job of keeping dust and contamination out. We were informed by Suntour that our EPICON fork could have come with an older batch of seals that would have caused the weeping. Apparently they have made improvements to their seals, but we need time on them to confirm the improvements.

Air Volume Adjustment:The air volume adjustment comes from a removable/cut-able yellow foam spacer under the top cap. Once you remove material from the spacer, there is no way of putting it back. It would be nice to see a system that allowed for infinite adjustability through multiple removable spacers like their RUX downhill fork. If not this, than at least shipping the EPICON with a few foam air volume spacers of different lengths to cover the adjustment range.

Long Term Durability

We've been riding the EPICON-X1 fork for nearly four months now, but more time is needed to really have a definitive answer regarding long term durability. Up until this point the fork hasn't shown any structural concerns and although the seals wept more than we'd like to see, the internals remained clean, smooth, and damage free. With the EPICON so user friendly to service, we can see more people getting their hands dirty and servicing the fork themselves. With regular service intervals this fork could run smoothly for many years to come.

What's The Bottom Line?

The SR Suntour EPICON-X1 fork is so close to being great, but the few key issues we experienced left some room for improvement. Luckily most of them have been addressed, and with the upgraded Q-LOC2 axle and seals it would be an excellent choice for the money. It's sufficiently stiff, supple, predictable, offers good support, and the adjustments work well, leaving no real complaints about the damper or chassis. While it may not be flashy looking, Suntour is definitely making a push in the right direction and we like what we're seeing.

For more info, visit www.srsuntour-cycling.com.

About The Reviewer

Evan Turpen has been racing mountain bikes for over 12 years. He raced downhill as a pro for the last 8 years with his career highlight being selected to represent the U.S. in the 2006 World Championships. More recently he can be found competing in enduro races and having a blast with it. His first ever enduro event being the 2012 Trans-Provence 7-day adventure race through France. He is an aggressive yet smooth rider who loves to flick the bike around to put it on the fastest line or to smooth out the rough sections. Fast flowy trails and long technical descents (Garbanzo style) are his favorite. Whistler and Santa Cruz are his two most favorite places to ride, but he can have fun wherever he goes. With an extensive knowledge of the mountain bike industry and its technologies, Evan is able to take all things in to perspective during a review. He has helped design, develop, and test products for multiple major mountain bike companies and has an attention to detail well above most. When he's not out ripping around on a bike he helps run the recently introduced California Enduro Series and is also in charge of the bike park at China Peak Mountain Resort.