Higher Education: Why and How to Upgrade Your Fork Damper

Upgrading components immediately after you buy a bike is usually not a cost-effective way to improve your ride. Sure, sometimes you don’t have a choice, like when bike manufacturers spec a tire that’s too light for your terrain or a dropper seatpost that’s too short for your legs. But when we’re talking about swapping for parts that are just nicer, you’re better off buying the bike that already has the spec you want. Unfortunately, it’s not that simple when it comes to suspension. Often, top-end fork and shock spec is the carrot that brands dangle on a stick that reaches way past the budget you’ve laid out for yourself. 

But if you find the perfect bike that has less-than-perfect front suspension, there’s a better option than spending $1,200 on the fork you want while fencing the one that came with your bike on Ebay. Arguably, the most important component of any fork is the damper. Top-end forks may have a lighter chassis or fancy coating, but it’s what’s inside that counts. Thankfully, it’s also what can be upgraded the most easily, and usually for around $300.

Damper Basics

Every major suspension brand relies on a hydraulic damping mechanism in one leg of the fork that prevents you from blowing too quickly through the travel on compression or popping too quickly out of it on rebound. Both can usually be adjusted through external knobs that restrict the flow of oil to suit your weight and riding style. But if it were that simple, suspension would be a lot cheaper and, frankly, a lot worse. Higher-end forks have damping characteristics that are speed- and position-sensitive, remain more consistent under abuse, and keep you in a more optimal position in their travel to make your ride smoother and safer. 

They also offer deeper customization options, often giving you the ability to adjust how firm the compression and rebound damping is based on the speed at which the fork is compressing and rebounding, cleverly called high- and low-speed compression damping. There’s also high-and low-speed rebound damping, which is a little misleading, but high-speed rebound damping controls how quickly the fork extends after big, near-bottom-out impacts while low-speed rebound controls how quickly the fork extends after shallower, less intense compressions. Understanding complex damper settings could be the subject of its own Higher Education story, but to put it broadly, high- and low-speed damping adjustments allow you to optimize the fork’s behavior not just for your style and terrain, but your skill level. Every rider can benefit from the performance and customization offered by high-end dampers. But they are expensive little devices, so they are reserved for high-end forks.

Believe it or not, installation of a new damper is relatively simple. There are few special tools involved, and few advanced techniques or frequent pitfalls to avoid if you aren’t a master mechanic. That said, we’re talking about an important component on your bike, and the consequences of not correctly finishing the job of servicing a fork can be serious. It shouldn’t be a very expensive service to have done at a shop if the videos we’ll link to look intimidating.

Fortunately, most brands stick to a standard internal structure across a given family of forks, and you can usually swap out the stock damper for the next model up. Or sometimes, you can even shop third-party brands who may make a fancy, boutique damper to fit your fork. And because RockShox and Fox are specced on the overwhelming majority of bikes, that’s what we’ll cover here.

RockShox

RockShox has two families of damping mechanisms, Charger and Motion Control. You’ll see Motion Control dampers on most of RockShox’s mid-range forks. They’re fine, but they’re rather simple, with no speed- or position-sensitive damping. The Charger damper, on the other hand, is better at recovering from small bumps and will keep you higher in the travel where the suspension remains more sensitive and your weight will remain more neutral over the bike. And it uses a flexible bladder to accommodate the shifting volume of oil, which helps the system remain free of air bubbles. 

You’ll find some version of the Charger damper installed on the burly, enduro-focused Zeb, the all-mountain Lyrik, the trail-oriented Pike and the cross-country SID. But each of these forks has a lower-priced version that will come with a Motion Control damper. In that same order, from enduro to cross-country, there’s the Domain, Yari, Revelation and Reba. Most, but not all of these forks can be upgraded to a Charger damper. To find out if your fork is one of them, and which one you would need, the RockShox website allows you to enter your fork’s serial number (on the above models, it’s located on the back of the crown, just below the steerer tube) to look up the correct model and part number. The current-generation aftermarket Charger upgrade kits are available in several configurations.

• Charger 2.1 RC2: The most finely tunable Charger damper, with adjustable rebound, high-speed compression and low-speed compression. This is our recommendation if you want the most benefits of a higher-end damper.
• Charger 2.1 RCT3: Offers the modern equivalent to a “lockout,” with a three-position dial to switch between “Open, Pedal and Firm” modes, as well as a low-speed compression damping adjustment to tune the Open mode, plus rebound adjustment.
• Charger Race Day: Only available for some SID and Reba models, this is the low-volume lightweight version of the Charger damper, and it offers rebound adjustment and an extra firm lockout.
• Charger 2 RLC Remote: The previous generation Charger damper has carried over because it is the only trail, all-mountain or enduro option to feature a two-position remote lockout, controllable from the handlebar. But it’s our experience that, outside of a cross-country race environment, fork lockouts are not useful enough to justify the clutter of a remote.

The Charger 2.1 product service page will help look up which Charger damper will work for Domain, Zeb, Yari, Lyrik, Pike and Revelation forks.

The Charger Race Day product service page will help look up which Charger damper will work for SID and Reba forks. 

So, great. Now you know if, why, and what you need to upgrade your damper. As for how to upgrade it, the easy way is to take it to your local bike shop. But it is not as intense a job as you may think. RockShox has a handy PDF that covers the process, as well as a compatibility chart if you don’t feel like doing the serial-number search. Keep in mind that a damper meant to fit a given fork will fit every travel length that fork is offered in, so there’s no need to find a “130-millimeter” or “150-millimeter” damper. If it fits your fork, it will fit your travel.

There’s also this video tutorial starring none other than Crankworx King, Mitch Ropelato that was clearly filmed during the holiday season. But it’s still pretty timeless.

Fox

This one will be a little easier to cover. Fox doesn’t offer as wide a range of price points as RockShox. And the price points Fox does offer tend to be higher, so it makes sense that every one of their forks can be fitted with that product family’s top-end damper. Same goes for the Bomber Z1 fork from Marzocchi, who is owned by Fox, though the lower-price Z2 damper is not upgradeable.

As you might expect when we’re talking about forks with such a high entry-level price point, even Fox’s simplest damper is pretty good. That would be the Grip damper. It offers high-end features like shim-based rebound damping for more consistent oil-flow control, and a compression damping system similar to what you might see on boutique brand forks like Öhlins. Basically, it is responsive, supportive, and has a wide range of adjustment. But it is only the simple adjustments of compression and rebound. For more complex options, you would upgrade to one of Fox’s more complex dampers.

• Fit4: A three-position compression dial offers either an extra firm lockout, a very supportive yet somewhat active medium setting, and an open setting with fine-tunable low-speed compression damping, as well as a simple but responsive rebound damping adjustment. 
• Grip2: Adjustable high- and low-speed compression and high- and low-speed rebound. Grip2 also features a patented technology on both high-speed rebound and compression called VVC that mimics the benefits of a completely custom tune, allowing you to increase damping for support without making the ride harsh. This is by far our favorite Fox damper here at Beta, and possibly our favorite damper period.

Compatibility is simpler with Fox because, again, most models can accept multiple dampers. And as with RockShox, they do not depend on your fork’s travel. But also, Fox offers fewer forks in general. Fox doesn’t even have a compatibility chart, but we can cover that pretty simply here.  

• 32 Step-Cast:  Grip, Fit4
• 34 Step-Cast: Grip, Fit4
• 32: Grip, Fit4
• 34 and Rhythm 34: Grip, Fit4, Grip2
• 36, Rhythm 36, and Marzocchi Z1: Grip, Fit4, Grip2
• 38: Grip, Grip2

Fox offers a tutorial on removal and installation only on the Grip2 damper, which has a slightly different first few steps than removing and installing a Grip or Fit4 damper. As with any repair, if you’re not completely comfortable with suspension service, it would be best to bring it to a shop, but you can find Fox’s Grip2 installation video here.

Photos: Ryan Palmer