PUSH Industries HC97 Hyper Charger Damper Modification Kit: Rider Review

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PUSH Industries has built a name within the MTB community for its uniquely custom-tuned coil suspension. Primarily seen on higher-end mountain bikes, PUSH's ElevenSix rear shock can be spotted a mile away and envied by riders all over the world. PUSH isn't all rear shocks though. They offer a Damper upgrade kit to modify existing Fox and RockShox forks to perfection. The HC97 Hyper Charger Damper Kit is no joke and you will usually only see it on the bikes of riders looking for a perfect setup. That being said, perfections also don't come cheap so these riders are also very dedicated to the sport. Our guy William recently made the upgrade and sent over a step-by-step walkthrough with his 2020 RockShox Lyrik. Let's see what goes into doing the upgrade and what Will's thoughts were after riding the HC97:

William's Review

PART 1: Getting the HC97 Kit

I currently have a 2020 Rockshox Lyrik Ultimate on my Pole Evolink 158 build. I love the fork for its super solid chassis and ease of overall maintenance. Full disclosure, I have a DSD Suspension "The Runt" installed on my air side and love how it works. That said, I recently decided that I'd like to have a bit more adjustment to the compression unit. Enter the Push HC97.

As I'm my own gearhead when it comes to working on my bikes, I decided to tackle this install myself, so I figured why not document it when I did it and share it after having some trail time on the unit? Ready? Here goes.

The Push HC97 comes in a simple box with the Push logo on it.

Upon opening it, you're greeted with the HC97 unit. Underneath the cardboard holding the unit, you'll find your rebound shims, a Push Sticker, and a card directing you to the install information.

My first impression of the unit is that it's really solid and seems quite well made. Everything is solid and has no unnecessary play.

PART 2: Deconstructing Your Fork

Once I visited the page for the deconstruction of the fork and the installation of the HC97 unit onto the damper, I decided that getting my tools together would be the best option to minimize having to "hunt" for tools during the installation process.

So, your basic list of tools for the HC97 install are:

1. Plastic faced hammer
2. 10" extension bar
3. ratchet handle
4. 10mm socket
5. Cassette tool
6. Adjustable wrench
7. 2.5mm hex wrench
8. 5mm hex wrench
9. and soft jaws for your vise

Now, I'll admit at this point that Push instructions indicated that I should install the fork into a rack to hold it. I left it right on my bike.

First, use the 2.5mm hex to remove the rebound knob.

Next, use the 5mm wrench to remove the rebound bolt 3 to 4 turns. Once done, strike it with the hammer to dislodge the rebound shaft. Fully un-thread the rebound bolt and set aside with the knob for re-installation later.

Next, use the 2.5mm hex to remove the screw from the compression knob assembly and remove the HSC and LSC knobs and set aside (you won't re-use these.)

Next, use the cassette tool to un-thread the damper unit.

Finally, remove the damper unit from the fork. I put a lint-free rag into the opening to ensure that nothing would end up falling into the fork while I was doing the next steps.

PART 3

Now, I had my damper/compression unit removed from the bike. The 2.1 damper looks like this in all its glory:

First thing I did with this is to install my soft jaws (these are not the right ones and I forgot to take the picture of it correctly set up....just ignore my stupidity and imagine these in the proper park soft jaws I have) onto the vise and clamp it onto the flat spots on the black metal tube as such.

Un-thread the red cap and remove the rebound shaft assembly using an adjustable wrench.

Remove the assembly from the vise and dump the oil out of it. I'd recommend letting it drip for a minute or two to save a bit of mess later. Once this was done, I had my shaft assembly and the compression assembly.

I then re-installed the compression assembly using soft jaws (Yes! I used the right ones this time!) with the compression unit facing up. It's a good idea to place a bucket under the unit, as it will drip whatever oil is still in it while you work. I then un-threaded the compression bladder ring (red) using an adjustable wrench.

PART 4

Next, I installed the 10" extension bar into my soft jaws with the 10mm socket on top of bar. The compression unit is slid down on this and slightly rotated until the socket engages the bolt.

Using the cassette tool again, I worked to remove the compression assembly from the tube.

Unfortunately, all did not go correctly, as instead of unthreading off the bolt, the cap for the stock compression assembly unscrewed instead. This left me with a bit of a problem of how to remove the compression assembly.

After a few minutes of consideration, I slid down the compression bladder and found a small "pass-through" in the stock compression unit. I passed a small hex wrench through it and used that to un-thread the compression unit from the bolt. I apologize that I do not have any pictures from that process, as it required both hands. However, if you look at this picture of the stock unit further on and you can JUST see the spot I am referencing to on the sides.

And now, I have what I was looking for! The bolt is accessible!

I removed the shims from on top of the valve from the bolt and carefully set them aside. Depending on your application, you might use many or all of them on your tuning process.

PART 5

So, now that I had the damper deconstructed, I gathered the parts that would be reused in the installation of the HC97.

Damper tube, Compression bladder, compression bolt (I neglected to include images of the check shim and spring, but they need to be reused as well), and the rebound shaft assembly.

From here, I gathered the tools I needed to install the HC97. Many are the same, but there were a few that you don't use on the stock unit:

1. 15mm cone wrench
2. 10mm box wrench
3. adjustable wrench
4. 5mm hex wrench
5. 2.5mm hex wrench
6. 2mm hex wrench (not pictured, but needed)
7. 1.5mm hex wrench
8. 10mm torx wrench (I used a bit in a ratcheting screwdriver...you'll see why this worked well later)
9. ratchet handle
10. 32mm chamferless socket
11. 10mm socket
12. 10" extension bar
13. torque wrench
14. soft jaws
15. charger bleed kit
16. blue Loctite
17. gloves (optional-I found them to be more of a hindrance than a help)

First step, I removed the HSC screw using the 2mm hex wrench.

Next, I used the 1.5mm hex wrench to loosen the set-screws on the sides of the LSC knob (I didn't remove them fully, just loosened enough to remove the knob.)

Next, I used the 10mm wrench and the 32mm chamferless socket to remove the top of the HC97 unit. I did not take a picture of the process, but the finished result looks like this.

PART 6

Since I hadn't removed the extension bar and 10mm socket from my vise, I placed the bolt with the spring and check shim onto it. I then slid the damper tube over it until it seated. I used a pick to ensure that the check shim could still move and was not pinched (I apologize that I don't have images for this). It should look like this:

From here, I put a SMALL amount of blue Loctite on the threads of the bolt, which looked like this. I actually applied it with a very small brush to ensure that it would not end up in my fork's inner workings and would only be on the threads.

Next, I took the compression bladder, applied a small amount of suspension lube and installed it onto the top of the HC97 unit. This was then placed on top of the tube/bolt. I carefully pulled up the bladder and used the 10mm socket on the notches of the HC97 to tighten it onto the bolt until it was snug. This resulted in it looking like such:

From here, the top cap for the HC97 is installed and tightened to 5.6Nm.

I next ensured that the bladder was not twisted and was fully in place over the end of the damper tube. The red ring is then slid up over the bladder to hold it in place.

For the tightening, I removed it from the vise and held it in my hands. The red collar is tightened until around 1 thread is visible at the bottom of it (instructions are specific that going more than 3 visible will damage the bladder, so I was extra careful here as the bladder seems to be about the hardest part to find by itself for this damper.)

PART 7

From here, it was time to do the "tuning", which meant changing the shims on the mid valve assembly. FULL DISCLOSURE here, I had the check spring from DSD that I also installed during this process. It's a slightly smaller spring rate and supposed to help aid performance.

The first step was for me to install the soft jaws on the vise and clamp them on the rebound shaft. The 10mm socket is then used to remove the bolt from the nut holding the shim stack.

This was the point where "oops" number 2 for me happened. Rather than the nut unthreading, the mid valve assembly unthreaded from the rebound shaft itself. After some more head-scratching, I was able to re-clamp the smaller part that remained into my vise and get the nut off.

Once the bolt was removed, I replaced the spring below the mid valve with the DSD one and placed it back into the vise.

I then had to measure the shims and compile the order that was advised for my rider weight of 195lb. It looked like this. The blue shims are the smaller ones provided by Push.

These are loaded in order of biggest to smallest back onto the mid valve. My result looked like this.

From here I installed the bolt and tightened it to 3.7Nm. Once that was done, I re-installed the mid valve shaft into the rebound shaft and all was right with the world.

PART 8

Now that I had assembled both the compression and rebound assemblies, I had the following.

The damper assembly was once again clamped into my soft jaws. At this point, I filled it with the fork oil from the bleed kit. The Rebound assembly is then placed on top of this carefully and the red collar is tightened until snug.

Next came bleeding the damper. Instructions state to fill the syringe 1/2 way with the oil. Understand that you will likely need to do this twice during this process to get a proper bleed.

Using the T10, remove the bleed screw and install the RockShox bleed syringe.

The bleed process is really quite simple. Depress the plunger on the syringe while cycling the rebound shaft up and down. This will push fluid into the HC97 unit and will cause the syringe to use most if not all of the oil in it. In my case, I had to fill the syringe a second time to ensure that I fully filled and bled the unit. Take your time with this....work out all the bubbles in the system. Doing this step right will ensure you don't have to disassemble your fork at some future date to bleed it again because you went too quickly here.

Once it's bled, allow the bladder to return to the resting state, remove the bleed syringe and install the bleed screw. Using the ratcheting screwdriver allowed me to do this really quickly without losing much oil.

A quick wipe down of the newly assembled unit gave me something that looks like this

PART 9

Now, I was on the home stretch of reassembly. A quick application of some RockShox lube to the outside of the damper bladder and tube and it was time to install the newly built unit into my fork. I carefully slid it into the fork and threaded the top by hand at first to ensure there wasn't any cross-threading. Once that was done, I used my 32mm socket to tighten it until snugged down good.

Next, I used the 1.5mm and 2mm hex wrenches to install the LSC and HSC knobs and snug them

I turned my bike over and carefully added 5ml of fork oil into the damper leg. I then used the 5mm hex to reinstall the bolt and snugged that good

Finally, I reinstalled the rebound knob and snugged that using the 2.5mm hex wrench.

PART 10: Conclusion

"So, now after all that work, the question becomes:
How does it ride?

In short, fantastic. The HC97 works really well with the Runt in my air side of my fork to provide great suppleness of stroke with great mid support without getting harsh at the end of my travel. I feel like my fork has less resistance to compressing, especially at the beginning of the stroke. The good news is this suppleness doesn't end up resulting in unwanted brake dive, as the fork still has great support. Repeated hits feel much less harsh and I don't have as much hand fatigue after riding.

Now, will I say that this is for everyone after buying a $900+ fork? Maybe not, but it certainly does make mine a lot more fun. The only real issue I have is that I've now added in even more to have to try to sort out in terms of my settings. However, the recommendation based on my weight from Push's website has it riding pretty damn well so far." - William