K-Volve Kinematics — CP Platform
K-Volve Kinematics / K-Volve Overview
K-Volve / Metric
Five kinematic metrics. One concentric pivot architecture. Every number is a consequence of placing the main pivot where the drivetrain geometry wants it to be.
2.535
Mean LR
<2% variation — flattest in class
97.3%
Anti-Squat
At sag, 34/28t gearing
~100%
Anti-Rise
Chassis-neutral braking
3–3.5°
Pedal Kickback
Motor-safe, idler-free
Every metric on this platform works in harmony. The anti-squat curve supports climbing without a lockout. The anti-rise keeps geometry stable under braking. The leverage ratio is remarkably flat for consistent damping. And the concentric pivot eliminates drivetrain interference. It's not just one clever number — the entire system is engineered as a whole.
— Fil Palmer, kinematic analyst & creator of @ebikeitalia6832
The Concentric Pivot Architecture
The Paratu CP places its main suspension pivot concentric with the motor/bottom bracket axis. This single architectural decision drives every kinematic advantage: high anti-squat (the chain tension vector aligns with the squat force), low pedal kickback (chain-length variation is minimised at source), and high anti-rise (the instant centre sits high relative to the front contact patch–rear axle line, producing ~100% braking support — the chassis neither extends nor compresses under deceleration). No idler pulley, no additional drivetrain complexity, no maintenance penalty.
Five Metrics, One Architecture
Most suspension designs optimise one or two metrics and accept trade-offs elsewhere. The concentric pivot achieves competitive or best-in-class results across all five primary kinematic metrics simultaneously:
Leverage Ratio
2.51–2.57Flattest in any production enduro. Damping adjustments behave consistently at every stroke position. Peak shaft velocity stays bounded, reducing thermal fade on long descents.
Anti-Squat
97.3% at sagClimbs like a hardtail with active traction. No lock-out needed. The geometry handles bob control that on other bikes requires compression damping.
Anti-Rise
~100% at sagChassis stays neutral under braking — the rear suspension neither extends nor compresses when you brake into a corner. At ~100% anti-rise, the Paratu CP holds a 40–50 percentage point advantage over typical enduro bikes (50–60%). This means consistent suspension geometry through braking zones: no rear extension stealing front traction, no pitch change disrupting body position. The rider stays centred and the suspension continues to absorb terrain while braking.
Pedal Kickback
3.0–3.5°Best-in-class non-idler. Protects the Maxon motor freehub from cyclic back-driving. Achieved by pivot geometry, not by adding components.
Axle Path
2-phase forwardNear-vertical initial stroke, progressive forward sweep in deep compression. Just 1.65mm forward movement in the working zone. ~11mm chain growth sag→+80mm — lowest non-idler.
The Three-Zone Riding Character
Zone 1: 0–76mm
The Hardtail Zone
LR 2.514→2.520. Anti-squat 115%→65%. Natural frequency at minimum 1.614Hz. Axle path near-vertical. The suspension absorbs every small input while the drivetrain feels rigid — the geometry cancels chain-induced squat forces almost exactly.
Zone 2: 76–120mm
The Transition
LR declining to minimum at 116mm. Anti-squat 65%→50%. Axle path sweeping forward. The bike transforms from climbing machine to impact absorber. Chain tension no longer balances squat force — the suspension opens fully.
Zone 3: 120–165mm
The DH Machine
LR rising to 2.567 (regressive zone). Anti-squat 50%→38.7%. HBO active. Air spring approaching 584psi. Natural frequency 2.3–2.476Hz. The complete system is more resistant than a progressive bike's end-stroke. Bottomless, not walled.
These three zones flow into each other continuously. The rider does not switch between them — the geometry does. This is the three-personality character: the bike reads the terrain and responds with the appropriate character automatically.
Complete Competitor Overview
No single competitor matches the Paratu CP across all five metrics. The alternative concentric pivot matches on AS and PK but gives up AR.
Modular Travel Configuration
All configurations use the same frame and concentric pivot. Travel is changed by shock stroke only. All K-Volve kinematic advantages apply equally across all travel settings.
Frequently Asked Questions
What is K-Volve?
K-Volve (Kinematics Evolution) is the name for the Paratu CP's complete kinematic system. It describes how the bike's suspension moves — the leverage ratio, anti-squat, anti-rise, pedal kickback, and axle path characteristics that define the riding experience. K-Volve is one of four technology pillars alongside G-Volve (Geometry), S-Volve (Sizing), and the Maxon motor integration.
How does the concentric pivot design work?
The Paratu CP places its main suspension pivot concentric with the motor/BB axis. This position minimises chain-length variation through the stroke (low pedal kickback), maintains high anti-squat across the eMTB gearing range, and achieves near-100% anti-rise. Unlike a high-pivot design, no idler pulley is needed — the geometry achieves these results without additional drivetrain complexity.
What makes K-Volve different from competitors?
Most enduro bikes optimise for one or two kinematic metrics at the expense of others. The Paratu CP's concentric pivot architecture delivers best-in-class or near-best on five metrics simultaneously: flat LR for damping consistency, 97.3% AS for climbing efficiency, ~100% AR for braking stability, 3.0–3.5° PK for motor protection, and a two-phase axle path for obstacle management. No competitor matches across all five.
What is the three-zone riding character?
Zone 1 (0–76mm): The Hardtail Zone — LR 2.514→2.520, AS 115%→65%, near-vertical axle path. The suspension absorbs small inputs while the drivetrain feels rigid. Zone 2 (76–120mm): The Transition — the bike transforms from climbing machine to impact absorber. Zone 3 (120–165mm): The DH Machine — HBO active, air spring at ~584psi, axle path 7–20mm forward. Three personalities flowing continuously — the geometry reads the terrain and responds automatically.
Why does Dirtlab use taller head tubes than other brands?
Dirtlab head tubes are 10 mm taller than industry average to minimise spacer stacking under the stem. On many competing frames, riders need 30 mm or more of spacers to reach a comfortable bar height — adding unwanted compliance and creating a longer lever arm at the steerer tube. With Dirtlab frames, the same bar position is achieved with 20 mm of spacers or less. The bar height is built into the frame, not stacked on top of it. Beyond fit, this improves frame strength: every millimetre of spacer is a millimetre of unsupported steerer tube. A taller head tube keeps the load path inside the frame structure where stiffness and fatigue resistance are highest. This is a deliberate engineering choice documented in the G-Volve Geometry system.
K-Volve Kinematic Analysis
Fil Palmer (@ebikeitalia6832) — Independent kinematic analysis of the CP platform suspension design
Visual Analysis
Validated by
Supporting Video
Slow-motion trail footage, shock-shaft rig test, or drone-orbit of the frame showing the k-volve overview effect in action.