Performance Scorecard Airflow Modularity & Tuning FEA & Longevity Compare

BUMP STOP BREAKDOWN · MK2 vs. MK3

MK2 vs. MK3

Both generations replace harsh solid-rubber bottom-outs with speed-sensitive pneumatic air damping.

MK2 is our proven one-piece bump stop—trusted by more than 7,000 drivers over the past four years, offering progressive air damping, specialty front travel options (−1/4" tire-rub, AHC, and Long Travel), and a 100,000-cycle / 2-year no-questions warranty.

MK3 re-engineers the bump stop into a modular, rebuildable system with up to 4× the air damping, swappable stiffness inserts for towing and overland loads, height adjustability up to an additional 4" of bump, and a 500,000-cycle / 8-year no-questions warranty.

WHICH ONE FITS YOUR BUILD?

Buy MK2 for a proven, budget-friendly OEM upgrade, occasional trail use, or specialty front travel (−1/4" tire-rub, AHC, and Long-Travel fronts)—backed by our 2-year no-questions warranty.

Buy MK3 if you wheel hard, tow, carry armor or campers, or want to adjust height and stiffness as your suspension changes—backed by our 8-year no-questions warranty.

MK2 ONE-PIECE FIXED
MK2 one-piece rear bump stops.
One Piece, Fixed Height: Printed as a single unit at the height you select at checkout, with specialty front heights (−1/4" tire-rub, AHC, and Long Travel) and a 100,000-cycle / 2-year no-questions warranty.
MK3 MODULAR 4-PART SYSTEM
MK3 modular rear bump stops.
Modular & Rebuildable: Separate folding stack, metered base, vehicle mounting plate, 1" height extenders, and swappable stiffness inserts—backed by a 500,000-cycle / 8-year no-questions warranty.

Performance Scorecard

Rated 1 to 5 across both bump stop lines
AIR DAMPING Bottom-out energy absorption
MK23 / 5
1× baseline air damping (+37% fast-hit force)
MK35 / 5
Up to 4× MK2 damping via larger air chamber
MODULARITY Swap parts instead of rebuying
MK21 / 5
One-piece unit
MK35 / 5
4 swappable building blocks · 108+ setups
TOWING & STIFFNESS TUNING Support for trailers, campers & armor
MK22 / 5
Fixed stiffness rate
MK35 / 5
Swappable inserts: Standard, +30%, or +60%
HEIGHT ADJUSTABILITY Change height when shocks change, or fine-tune travel
MK22 / 5
Fixed height chosen at checkout
MK35 / 5
Stack 1" extenders up to +4" of additional bump
LONGEVITY & WARRANTY Dyno cycle life & replacement coverage
MK23 / 5
100,000+ cycles · 2-year no-questions warranty
MK35 / 5
500,000+ cycles · 8-year no-questions warranty
SPECIALTY FRONT TRAVEL OPTIONS −1/4" oversized tire-rub, AHC & Long-Travel fronts
MK25 / 5
4 front options: OEM, −1/4" tire-rub, AHC & Long Travel
MK33 / 5
OEM front height only — get MK2 if you need −1/4" fronts

01 — AIR DAMPING & INTERNAL PASSAGEWAYS

How Air Absorbs the Hit
(Without Oil or Nitrogen)

Solid rubber acts like a spring and bounces energy back into your frame.

MK2 and MK3 trap air inside the shell and vent it through metering ports—giving you a hydraulic-style catch with zero oil seals, nitrogen lines, or rebuilds.

MK3's thin folding shell frees up a much larger air chamber for up to 4× the damping of MK2.

Side-by-side cross-section comparison of MK2 and MK3 bump stops showing internal airflow pathways.
MK2 internal cross-section and pneumatic airflow callouts. MK3 internal cross-section and pneumatic airflow callouts.
INSIDE THE CUTAWAYS Left (MK2): Prints the outer shell, progressive lattice core, center bellows, and ports as one piece. Right (MK3): Separates the folding stack, swappable open-cell insert, and threaded metering base. Top (MK2): Prints the outer shell, progressive lattice core, center bellows, and ports as one piece. Bottom (MK3): Separates the folding stack, swappable open-cell insert, and threaded metering base.

How Pneumatic Air Damping Works in Both MK2 & MK3:

STAGE 1 · BOTH MK2 & MK3

Soft Slow-Speed Engagement

In both MK2 and MK3, air vents freely through the ports on slow rocks so you keep your full suspension travel.

STAGE 2 · BOTH MK2 & MK3

+37% High-Speed Support

On a fast hit, air can't escape the ports in time—spiking internal pressure for up to 37% more support force (with up to 4× total energy absorption in MK3's larger chamber).

STAGE 3 · BOTH MK2 & MK3

Controlled Rebound Return

As the suspension unloads, restricted air intake slows the return stroke so neither bump stop kicks your truck back up.

02 — MODULARITY, TUNABILITY & HEIGHT ADJUSTABILITY

Grow Into It. Don't Replace It.

With MK2, changing your shock travel or rear payload means buying a new bump stop. MK3 unthreads by hand so you can adjust height, stiffness, or vehicle mounting in minutes.

MK3 MODULAR SYSTEM 108+ COMBINATIONS
Animated GIF showing MK3 modular stacks, extenders, and vehicle mounting plates swapping across configurations.
One core system adapts across stack heights, 1" extenders, stiffness inserts, and vehicle-specific frame plates.
HEIGHT ADJUSTABILITY · EXTENDERS

Up to +4" of Additional Bump in 1" Steps

Start at OEM height. Whenever you install longer-compressed-length shocks, stack 1" extenders between the base and stack—up to 4" of additional bump.

STIFFNESS TUNABILITY · INSERTS

Towing & Heavy Overland Loads

Unthread the base and drop in a breathable open-cell insert:
No Insert for trail compliance,
+30% for mid-weight racks, or
+60% for towing, campers, and heavy steel armor.

DIRECT FIT · BASES & LASER-ETCHED PLATES

No Cutting, Welding, or Drilling

Vehicle-specific steel plates bolt straight to factory frame holes and include laser-etched orientation, preload specs, and a QR install code. Get Hydro-like performance without the cost of fabrication.

OEM (0")0 SPACERS
MK3 stack at OEM height with 0 extenders.
Base Stack0"–0.4" longer shock
+1" BUMP1 SPACER
MK3 stack with 1 extender.
+1" ExtenderExtended travel (0.5"–1")
+2" BUMP2 SPACERS
MK3 stack with 2 extenders.
+2" ExtendersLong travel (>1" shock)
+3" BUMP3 SPACERS
MK3 stack with 3 extenders.
+3" Extenders+3" bump extension
+4" BUMP4 SPACERS
MK3 stack with 4 extenders.
+4" ExtendersMax +4" bump extension
Swappable open-cell stiffness inserts.
SWAPPABLE STIFFNESS INSERTS (+30% / +60%) Open-cell lattice adds mechanical support for towing while letting air flow into the base ports.
Laser-etched MK3 mounting plates.
LASER-ETCHED VEHICLE PLATES Permanent etched fitment ID, inboard/outboard arrows, 3-turn preload spec, and QR instructions.

03 — LONGEVITY & WARRANTY

Why MK2 Survives 100,000+ Hits — And MK3 Reaches 500,000+

Under full compression, a tapered cylinder bulges outward along a single waist crease (concentrating strain in one band), while MK3's origami Yoshimura shell folds along pre-engineered facets to spread stress evenly across the entire shell.

MK2 COMPRESSION 100,000+ HITS
Animated press test of MK2 bump stop bulging outward along a single waist crease under full compression.
MK2 Outward Bulge (2-Yr Warranty): Compresses into a single barrel bulge around the waist—proven past 100,000+ cycles on our test rig.
MK3 FEA SIMULATION 48 FPS FEA
48 fps Finite Element Analysis simulation of MK3 bump stop compressing along its Yoshimura facets.
MK3 Stress Distribution: Yoshimura facets guide the wall to fold along engineered hinge lines instead of concentrating stress at one pinch point.
MK3 DYNO VALIDATION 500,000+ HITS
MK3 bump stop under full compression on the Perry Parts suspension dyno.
MK3 Controlled Fold (8-Yr Warranty): Validated past 500,000 full-compression hits on our dyno. Break either line for any reason and we replace it free.

04 — SIDE-BY-SIDE SUMMARY

MK2 vs. MK3 at a Glance

FEATURE MK2 MK3
Design One-piece printed bump stop 4-part modular system (Stack, Insert, Extender, Base/Plate)
Air Damping Significantly more damping than regular rubber Up to 4× MK2 damping
Stiffness Tuning Fixed stiffness rate Swappable inserts: Standard, +30%, or +60%
Height Adjustability Fixed height chosen at checkout Up to +4" of additional bump in 1" steps
Front Travel Options OEM, −1/4" Tire-Rub, AHC & Long Travel OEM equivalent height
Towing & Armor Light to moderate rigs, custom designs available for heavy builds Recommended for towing, campers & heavy armor
Dyno & Warranty 100,000+ cycles · 2-Year No-Questions Warranty 500,000+ cycles · 8-Year No-Questions Warranty
Starting Price Fronts from $99 · Rears from $135 Fronts from $239–$269 · Rears from $314

Shop MK2

Simple, proven, budget-friendly pneumatic upgrade over factory rubber.

  • Daily drivers and occasional weekend trail rigs
  • −1/4" Up-Travel front tire-rub, AHC, and Long-Travel fronts
  • 2-Year / 100,000-Cycle No-Questions Warranty
SHOP BY VEHICLE SHOP MK2 FRONTS

Shop MK3

The last bump stop you'll ever buy—built to adjust as your truck grows.

  • Up to 4× MK2 air damping with Yoshimura folding shell
  • Up to +4" height adjustability & +30% / +60% towing inserts
  • 8-Year / 500,000-Cycle No-Questions Warranty
SHOP MK3 BY VEHICLE SIZING GUIDE

Designed, tested, and printed in-house in Lebanon, NH. Check your shock's compressed length in the Bump Stop Sizing Guide or read our Warranty Page.