PERSONAL INTRODUCTION
My first experience with a RockShox Boxxer that truly made me understand why this fork has the status it does was on my first serious downhill bike:
a Commencal Supreme V3 on 26-inch wheels. Those were the times.
Rockshox Boxxer 2015 - 2018 World Cup exploded view:
After a while, I upgraded to a 27.5 Boxxer taken from a Nukeproof Dissent and made the bike a mullet.
The difference was much greater than I expected.
The bike became faster, more comfortable on the trail, and much more “planted,” as they say in the moto world.
It held the line better, had more grip up front, and it felt like the whole bike became calmer at speed.
The big surprise was that I sold the old 26 Boxxer almost instantly after posting the ad. Well, it had all the maintenance done up to date and was obsessively cared for.
Then came the Nukeproof Dissent, which came with a 27.5 fork. I later put a 29 Boxxer on it and again felt a serious difference.
More stability.
More control.
Less panic in the fast sections.
In the meantime, I also got a Commencal Supreme V4.4 in full 29 configuration, a bike that unfortunately is no longer produced and which I still can't explain why it is faster than the current Supreme V5.
And yes, I even tried putting a 29 wheel on the back of the V5.
It still didn't catch up to the V4.4.
If you have an explanation for that, I'm really curious to hear it.
An even bigger surprise came in 2024 when the Commencal Supreme V5 was equipped with Boxxer D1, already on the new 38 mm chassis.
Pure butter.
There I really felt that the Boxxer made a major leap:
more comfort,
more grip,
less fatigue in the hands
and a very strange feeling of control at high speed.
Why Boxxer D1 was such an important moment
Many people reduced D1 to:
“they made the 38 tubes.”
But the real change was much more complex.
Yes, the Boxxer needed more stiffness:
bikes had become longer
29-inch wheels put more pressure on the chassis
speeds had increased enormously
modern brakes generate much greater forces
The problem is that too much stiffness can make a fork tiring and without grip.
And this is exactly where SRAM did something very interesting.
In the official development for Boxxer D1, engineers say that the first prototypes were too stiff and did not offer enough compliance on rough terrain.
So they started optimizing:
wall thickness
crowns
lower legs
flex distribution
to achieve a balance between:
precision
torsional stiffness
comfort
grip
And now, in 2026, with the arrival of the D2 generation, I wanted to share with you what I discovered and also go through the history of one of the most important forks in downhill.
Source: https://www.sram.com/en/rockshox/series/boxxer
The new RockShox Boxxer D2 does not try to be the stiffest downhill fork on the market. And that’s exactly what makes it interesting.
Charger 3 – the part that many underestimate
Charger 3 changed the feel of the Boxxer more than the 38 chassis.
Many riders say about the new Boxxer that:
it is smoother
less harsh
calmer on braking bumps
less tiring on long trails
And a large part of this feeling comes from the new Charger 3 damper.
The problem with Charger 2.1 was that sometimes the damping became harsh on very fast and repetitive sections. Especially:
braking bumps
fast rock gardens
consecutive roots
Charger 3 comes with:
greater oil flow
redesigned piston
better separation between HSC and LSC
more consistent response
High Speed Compression controls fast impacts:
rocks
roots
strong hits
Low Speed Compression controls:
weight transfer
braking dive
pumping
bike support
On Charger 3, the adjustments are much clearer and easier to feel according to feedback received by SRAM from World Cup riders and from tests published after the launch.
ButterCups – marketing or do they really work?
Honestly, I was skeptical at first.
But the idea behind ButterCups is very interesting and has technical logic.
Very important:
ButterCups are NOT about big impacts.
They target small and fast vibrations:
braking bumps
chatter
gravel
small repetitive roots
SRAM claims they reduce high-frequency vibrations by up to 20%.
Many riders and mechanics who have tested the new platform say the difference isn't necessarily something you notice instantly in a parking lot, but it becomes apparent after long and very rough descents, where accumulated fatigue starts to matter.
This is probably one of the most important directions in modern downhill suspension.
It's no longer just about:
“what the bike does in the first minute”.
But:
“how you feel after a whole day of riding”.
[IMAGE 8 – ButterCup close-up / exploded view]
Source:
ButterCups Technology
Damper side buttercup
Spring side buttercup:
What’s new in the D2 generation
D2 doesn’t seem to be a complete revolution, but rather a refinement of the D1 platform.
From the information presented by SRAM and feedback from riders who have already ridden the new generation, the main focus seems to be:
reducing friction
more grip on small bumps
more consistent damping on long descents
more comfort without loss of support
SRAM talks a lot about:
predictability
vibration control
reducing rider fatigue
And honestly, that seems to be the direction of the entire industry now.
Not just:
stiffer
more aggressive
more race-oriented
But:
more controllable
calmer
more efficient in the long run
Why I believe modern downhill is heading in this direction
A few years ago, everyone was obsessed with:
stiffness
extreme geometry
“the most aggressive bike”
Now it seems the industry is starting to understand something very important:
too much stiffness can fatigue the rider.
And the Boxxer D1 and now D2 are very much heading in the direction of:
vibration control
reducing fatigue
composure at high speeds
And honestly, I believe that matters more than another 5% stiffness in a catalog.
Conclusion
After all the upgrades we've gone through:
26
27.5
mullet
29
D1
I can clearly say that the evolution of the Boxxer has been felt on the trails with every significant generation.
And from what SRAM presents and the riders who have already tested the new D2, it seems that the current direction is no longer about making the fork as stiff as possible.
But about making the bike:
more controllable
less fatiguing
and faster exactly when the trail gets very rough and the speed starts to become absurd.
How Boxxer has evolved over the years
RockShox launched the first Boxxer in 1996. At that time, downhill was completely different:
26-inch wheels
short frames
nervous geometry
much slower trails than today
The first Boxxers were practically tanks:
heavy
simple
very durable
But for that time, they seemed futuristic.
By 2008, the 35 mm generation appeared, which practically defined modern downhill for many years.
This fork was everywhere:
World Cup
bike parks
production bikes
custom builds
Then came the Charger Damper, and here the Boxxer began to become much more refined.
It was no longer just:
“a big and tough fork”.
There began to be a focus on:
control
damping
feedback
high-speed behavior