Marginal Gains: There’s Nothing *Stock* About Stock Suspension 32

Marginal gains are what drive the cycling industry. From year to year, brands are constantly making minute adjustments to make sure they always have the next best thing. A half-degree here, and a couple of grams there...and while the never-ending updates may frustrate some riders, their cumulative effect has led us to thirty-pound trail bikes that are shockingly capable. One of the most elusive updates is the “perfect” suspension configuration and setup. While throwing money at custom tunes and aftermarket bolt-ons may be necessary in extreme circumstances, we wanted to dive a little deeper into “stock” tuning. How do suspension brands approach this process? How does their approach impact the end-user. Thankfully, Norco Bicycles opened their doors for us, and FOX Factory also allowed us to tag along for a weekend of tinkering, in addition to sampling a variety of setups, to get the most out of our Norco Optic daily driver. 

Introduction

Earlier this year we tested a handful of slack, short-travel trail bikes. There were a few great options to choose from, however we also found that such capable geometry and so little travel highlighted the importance of shock tunes and setup for ideal performance. Later in the year, Diaz Suspension Design also helped us to explore how custom tunes impact performance and the fun factor for Brandon Turman’s ride at the time. In both cases, we noted improvements, but also compromises when it came to stock versus custom tuning. We weaseled our way into a Fox Factory testing session alongside product managers from some of British Columbia’s biggest brands to learn more about their quest for perfection. 

Looking back at our first experience aboard the Norco Optic, we liked that the firm compression tune made things lively and fun, but also noted that it might have been too firm for lighter riders. We also felt that the rebound didn’t provide quite enough adjustment, which left further room for improvement. For 2021, the Optic is available with both a RockShox SuperDeluxe Ultimate DH and the Fox Performance Elite Float DPX2. Even though our previous experience was on the RockShox unit, we were excited to see how the stock 2021 FOX DPX2 compared and wanted to experiment with a variety of setups to determine whether we could improve the Optic’s performance for our needs.

Test Location

The Nanaimo-based FOX Factory tuning camp was targeted at short to mid-travel bikes. We spent our time at the base of Mount Benson, lapping a few loops to test a variety of setups. Mount Benson is not as technical as areas like Squamish, however the terrain there is still on the technical and steep end of the spectrum. Our go-to lap was a flowy trail called Shenanigans, which was firm and fast, but appropriate for mid-travel bikes and had enough variety to allow us to determine our handling likes and dislikes. We did manage to mix in a few burlier trails, many of which exceeded the intended use of a “little bike”, but knowing our own riding tendencies and those of Vital MTB readers we knew it had to be done (for the sake of journalism). 

When it came to location, Norco’s suspension development expert Arthur Gaillot noted that “we've tested on short, fast, firm (trails) in the past. It's effective and can be part of a thorough process without a doubt. Limitation if used exclusively is that you'll end up with a tune that is overall ‘a bit much’...we found it takes more time than one would think to put together the right testing ground to even start testing…”

Before the ball even got rolling with shock tuning, Norco Engineer Colin Ryan added:

“Optimizing a bike around a single shock isn’t always feasible. We incorporate spring data early on in our development process so that we can consider how kinematics combined with spring characteristics will translate into ride feel. From a damping perspective, the suspension manufacturers we work with offer a wide range of compression and rebound tune options, but we still need to be conscious of what is available when we start developing kinematics for a bike. As we get more familiar with how a manufacturer’s base tunes function with different kinematics, we can narrow down the tune options that need to be ride tested before we select a base tune for the bike…we reduce the number of different shocks we spec on a bike to ensure we get the same ride characteristics across all spec levels.”

Stock Tune

Our first lap aboard the Optic was on the stock 2021 Fox DPX2: light compression with digressive rebound. When chatting with Norco about why they went with this route they noted that the lighter compression tune offered improved small-bump and square edge performance, while the digressive rebound mellows things out near bottom out to keep the bike from getting too unsettled through successive holes and at high speed. 

Ryan explains the stock tune and Optic’s intended use in detail: 

“We are running a Light Compression tune (CL) with a Digressive Rebound Medium tune (DRM), 0.6 volume reducer. Testing on the Light Compression tune showed it is well-matched to the Optic’s starting leverage for both wet and dry conditions, and the expanse of rider weight ranges…and mostly as an overall setup for the variety of trails within the intended purpose, at all times of year.  

The Optic is designed to be an aggressive short travel platform that maintains speed and feels dynamic in heavy compressions, steep lips, and coming out of corners, while still tracking in the rough. It will track in rough, natural, chunky terrain considering the support it provides in the above, but if all you are riding is rough natural trails, you will likely be better served by more travel – simply allowing the wheel to move out of the way of the obstacle for less rider feedback.

By default a base tune covers a range of riders from 240lbs to 120lbs and their proportional spring rates. Support for the mid to upper segments of this range translates to a more damper-dominant setup at the lower end.  And vice versa: if a tune provides exemplary tracking at the low end of the rider weight range, it will likely exhibit spring dominance and not present the same level of control for the mid to high end of the weight range. This is especially true when you are working with shocks that lack a low-speed and high-speed range of external damping adjustments…it's give and take.

Our end goal is to produce a bike that can be optimized for different rider skill levels and morphology thanks to geometry and kinematic traits, base tunes and by providing riders with detailed Ride Aligned setup guides.”

The Optic felt good out of the gate, but this tester’s 185 pounds (~84 kgs) is on the heavier side of Norco’s spectrum, and with an aggressive riding style and in fast terrain we felt that more initial support would allow us to press into corners without using too much travel, but still provide ample small bump sensitivity.

Custom Tune

We then tried Fox’s over-the-counter aftermarket tune: medium compression, medium rebound. We started with 245psi and 30% sag, and zero volume spacers. The added compression was an immediate advantage. We had more support while climbing without any perception of harshness, and on descents the bike was livelier and retained more travel for when we really needed it. Because the trails weren’t overly technical the quicker recovery of the medium rebound was beneficial too. The standard compression tune might have felt better had our test taken place on slower or more technical trails, but for a fast, firm trail like Shenanigans medium compression was our preference. After some experimentation, we still wanted more from mid-stroke through to bottom out, and because we were happy with the performance off the top, Fox suggested that the installation of volume spacers would do the trick.

Fox offers spacers in 0.2mm increments, and based on our feedback the Fox technicians recommended we run 0.6mm, which also happens to be the stock spacer. We reset sag to 30%, now at 230psi and returned to the identical loop. We were immediately impressed by the change. No difference in small bump sensitivity, with the added mid-stroke and bottom out support that we were hoping for. For us, the firmer-than-stock compression tune and 0.6mm spacer felt just about perfect. Shock now updated, we chatted with Norco’s engineering team to determine why they settled on the lighter tune. 

Without hesitation, Ryan hypothesized on why we favored a more supportive setup: 

“A short test loop doesn’t create the same rider fatigue, so often a firmer, more positive setup is seen through its strengths while its limitations may only transpire when the bike is taken on longer tracks (and) rides.  Both the ground type and test track length would allow you to get away with more damper presence without presenting obvious negative traits.  Bumping up compression and dropping pressure some would show promise in my mind on the type of ground you may have tested on that has more cushion, within the context of the testing, and the time of year. We did test the medium compression tune on harder, faster trails… this translated into sharpness in the rough and generally a bit more feedback than desired for the purposes of a base tune.”

Ryan also noted that Norco’s base tune leaves room for improvement depending on the rider: 

“I could see lighter riders who ride only natural trails may be better served by opening up the air volume in the shock with a bit more pressure than Ride Aligned suggests. That said, this won’t be as dynamic when the trails get firmer and the ground less naturally complex. I could see heavier or more aggressive riders on softer ground, who run a more significant rearward offset being better served by more compression and a non-digressive rebound tune (this statement describes this tester just about perfectly, and also nails our preferred tune at the camp). That said, this will compromise traction on wet, loose surfaces at slower speeds and will be on the sharp side in dry, loose over hard surfaces, on longer descents especially.”

Time will tell for traction in the wet, but it’s raining cats and dogs at the moment in Squamish, so the compromises of a firmer tune may soon appear to us.

Debrief

We mentioned initially how marginal gains drive the industry, along with the never-ending quest for “perfect” suspension. Simply put: between frame manufacturers and suspension companies, nearly no stone is left unturned. The process is extremely thorough, which ultimately has led us to great bikes. Just about anybody can hop on a “stock” bike and shred without spending more than a few minutes setting sag, and those with more specific taste can get things dialed with some attention to detail. Gains and compromises were evident from one setup to the next, which also confirmed that perfection will never exist. There are simply too many variables. This underscores the importance of consumers gaining a better understanding about how their suspension works, in addition to what changes they can make themselves to optimize performance, along with potential adjustments as trails, terrain, and weather change. After all, incorrect suspension settings will adversely affect any bike.

After our session, we sat down with Fox Factory’s OE Sales Manager Vince Marcotte to chat more about what goes into their tunes, and how they work with various brands and product managers to land at the ideal tune for any given bike. Marcotte noted the challenges that brands face when deciding which tunes are best, knowing that no two riders are the same. He also noted that this tester’s preferred tune wasn’t surprising given what, where, and how he rides. Marcotte also chooses the Optic, and runs a firmer-than-stock tune. He noted that brands are constantly seeking the ideal balance, while providing enough adjustability for individual tuning. Brands like Norco have gone to great lengths with their Ride Aligned setup guide which helps consumers to get even closer to the ideal setup with less trial-and-error. 

Fox Factory’s OE Sales Manager Vince Marcotte in Audio

We left Nanaimo with more appreciation for just how much time, energy, and attention to detail goes into “stock” shock tunes. For anything beyond, Marcotte noted that Fox Factory and a number of approved tuning centers can make further adjustments for folks with highly specific needs that can’t be met by stock tunes. 

Suspension Tuning For Dummies

Here’s a quick refresher from Fox Factory to help get the most from your Fox air shock:

1. Sag must be set first, and properly. Amount of sag varies depending on frame, but the order of operations doesn’t. 25-30% is common for rear shocks. If you’re unfamiliar with this process, check DIALED. 
2. Rebound settings should always be the second adjustment after sag is set. Rebound controls how the forces stored during a compression are released. Low-speed rebound controls the recovery from a low velocity impact. This correlates to rebounding after pedal input, riding over roots and rocks, and brake diving. High-speed rebound controls the recovery from a high velocity impact. This correlates to landings off drops and square edge hits.
3. If more progression is needed, add volume spacers. This will require that steps one and two are repeated. 
4. Compression settings are the last adjustment to be made. Low-speed compression controls low velocity forces. This includes your pedal input, riding over roots and rocks, and brake diving. High-speed compression controls high velocity forces. This includes landings off drops and square edge hits. If you want a firmer or softer ride in any of these areas, adjust accordingly.

For another in-depth look at suspension setup, check Jordi’s Basic Suspension Setup.

Suspension is a seriously deep rabbit hole, but the basics listed above, in combination with some attention to detail and deliberate tinkering will get you closer to “custom tuned” than you ever thought possible. Our advice: if you haven’t checked your suspension settings lately, take a few minutes to double check, head out for a ride, note any changes you’d like to make, use the steps above, and go from there...

About The Reviewer

Joel Harwood – Age: 36 // Years Riding: 20+ // Height: 5’11” (1.80m) // Weight: 185-pounds (83.9kg)

Joel’s unique coaching background and willingness to tinker with products bring an objective perspective to testing. He dabbles in all types of racing, but is happiest simply exploring the limitless trail networks surrounding his home of Squamish, BC. Attention to detail, time in the saddle, and an aggressive riding style make Joel a rider that demands the most from his products while exposing any shortcomings. 

Photos courtesy of FOX