CP Suspension Setup

The shape of the LR curve is not what matters to the rider — its consequences are. A flat LR (~2% on the CP platform) gives you two first-order benefits:

1. Uniform damping authority through the stroke. Damping authority at the wheel scales with LR^2. A 25%-progressive frame loses ~36% of its damping authority deep in the stroke (LR drops from 2.5 -> 2.0). On the CP, LR^2 varies by ~4-5% across the stroke. A click of LSC at 20mm does the same job as a click at 140mm — the adjustment behaves the way the rider expects.
2. Thermal stability on long descents. Damper heat rate scales with shaft velocity squared. A flat LR bounds peak shaft velocity for a given wheel speed, so the shock runs cooler over a sustained 8-12 minute descent. Less oil shear, less viscosity drop, less damping fade.

End-stroke ramp comes from a different source — see the bottom-out question below.

Three sources working together, not one:

1. Slightly less than 30% sag (we target 28%) — leaves more spring travel in reserve.
2. Progressive air spring with two positive and one negative volume spacer (DVO Topaz T3 reference tune).
3. Hydraulic Bottom-Out (HBO) circuit active in the deep zone.

Combined, the system delivers a 3.08x wheel-force ratio from sag to full compression. For reference, the most progressive linkage in this segment (~29% kinematic progression with a standard air spring) produces approximately 2.29x at the wheel. The CP platform's complete system delivers 34% more end-stroke resistance than that benchmark — from air + HBO instead of from linkage geometry. Independently verified by Phil at Bike Italia / MTBtech.

HBO (Hydraulic Bottom-Out) is a speed-sensitive circuit in the deep stroke of the damper. Unlike linkage progression or an elastomer bumper — both of which are position-sensitive — HBO knows the difference between a fast square-edge hit and a slow G-out, and responds differently to each.

On a slow 80%-travel compression, HBO does not engage hard — the bike feels plush through long compressions. On a fast square-edge at the same travel position, HBO ramps hard — exactly where the rider needs the protection. That behaviour is impossible to produce from linkage progression alone, because the linkage cannot tell the difference between fast and slow.

On the CP-platform setup we run, the HBO is one of three end-stroke tools (sag, air spring spacers, HBO) acting in concert. Race terrain produces a mix of fast and slow bottom-out events; HBO handles the mix better than passive bumpers.

The 97.3% figure is simulated at 34/28t with realistic rider weight — the gear and condition that reflects real climbing use. Some manufacturers quote anti-squat at standstill with optimistic gearing; that produces a higher headline number but is not what the rider experiences.

97.3% sits just below neutral at sag. Pedal input through the middle of the gearing range produces essentially no suspension compression. The bike climbs like a hardtail — no shock lock-out is needed on technical climbs. Phil's independent ASP analysis confirmed this figure at his measurement condition.

Anti-rise is 49.1% at sag (kinematic simulation) — tuned so the rear stays composed and predictable under hard braking, keeping the bike calm and planted when you need it most.

On a long technical descent — particularly braked sections into corners — the suspension stays active and the bike stays settled.

Yes — and we won't pretend otherwise. Forward axle path imposes a real harshness penalty on square-edge hits because the wheel has to decelerate against the direction of travel. A well-executed high-pivot will beat a forward-path frame on pure small-bump-to-mid-stroke smoothness over repeated rocks at speed. That's the one kinematic axis where high-pivots are honestly stronger.

Our answer is to quantify and contain the trade-off:

• Forward excursion at bottom-out is approximately 8 mm — on the low end of forward-path frames, well below older Horst-link designs at ~12-15 mm.
• Low chain growth in the working zone (see chain-growth question) so the drivetrain doesn't add a second harshness source.

The CP platform competes on balance, weight (eBike build ~18 kg vs comparable high-pivot eBikes ~22 kg), drivetrain simplicity, and absence of an idler bearing on the service schedule.

Both observations are correct. Some kickback genuinely makes a bike feel alive under pumping on flow trails — perceived 'pop' on a pump track comes partly from the suspension resisting compression under pedal input.

The CP platform delivers support differently. PK at 3-3.5 deg is low but not zero, paired with 97.3% anti-squat. On flow terrain the bike feels firm under pedalling load because high anti-squat keeps the rear from sinking when you pump — the AS is doing the support work, not the kickback.

The felt difference: the CP platform is quieter through the drivetrain. Riders coming from bikes with 10deg+ kickback may read the quietness as 'less alive.' That's a feel preference; the right way to resolve it is on a test ride, not on the spec sheet. Phil's independent measurement confirmed PK at 3-3.5 deg, below the threshold most riders can perceive.

Classic effect of pedal kickback and mid-stroke chain growth fighting the suspension through repeated hits. The rear triangle is trying to compress; the chain is trying to pull it back through its arc; the rider experiences that tension as the bike 'running out of travel' even though the on-paper travel is plentiful.

An idler eliminates this, at the cost of weight, drag, and a service interval penalty. The CP platform avoids it differently — by kinematic architecture (concentric pivot keeps the chain's effective pivot close to the chainring's rotational axis), so chain length change through the working zone is minimal, without an idler. Result: the CP feels closer to a high-pivot than to a typical VPP on rough chunder, but with simpler drivetrain and lower weight.

Approximately 11 mm of chain growth from sag to +80 mm — the window where the rider lives most of the time, and where drivetrain-induced harshness is actually perceived.

Comparable VPP frames sit closer to ~12.5 mm in the same window. Idler-equipped high-pivot frames go lower, near zero, but with the trade-offs noted above.

Among non-idler enduro frames in this segment, the CP platform has the lowest chain growth in the working zone. That's a direct outcome of placing the main pivot concentric with the chainring area — the architecture's primary kinematic payoff lives exactly in the meaningful working window.

The intuition is universal in the rider community and it's about half right. Air cans do heat. But the air spring is not the dominant heat source on a rear shock.

Where the heat actually comes from on a 10-minute descent (~2,000 significant suspension cycles):

• Air spring (adiabatic compression): ~2-5 J/cycle -> ~6 kJ total -> ~9% of the thermal budget.
• Damper (viscous shear): ~30 J/cycle -> ~60 kJ total -> ~91% of the thermal budget.

The damper dissipates roughly 10x more heat than the air spring. That hot rear shock you felt after a long descent is mostly damping oil, not air.

Why a coil swap doesn't fix it. A coil eliminates the ~9% air-spring contribution. But the damper architecture is identical — same shim stacks, same oil, same shear mechanism. Coil shocks also have an IFP gas chamber that heats. What riders actually feel from coil is lower static breakaway friction and a flatter spring rate as the shock warms — both genuine benefits. 'Coil runs cooler' is not.

Why the 230x65 mm shock on the CP platform is thermally excellent:

• Largest practical air volume in the segment -> compression ratio ~1.64 (vs 205x60mm shocks at ~1.90) -> ~25-35% cooler air spring per cycle.
• Flat LR bounds peak shaft velocity -> lower peak damper power dissipation than progressive-LR competitors.
• Longer shock body -> ~12% more aluminium mass and surface area than a 205mm shock -> more thermal capacity, better convective cooling.

All three approaches work — they solve the same problem with different tools:

• Hydraulic Bottom-Out (HBO): speed-sensitive, tunable by shim stack and port geometry. Used by DVO (Topaz T3), Fox (X2), Ohlins (TTX2 Air). Best match for race terrain because it discriminates fast vs slow bottom-out events.
• Elastomer bumper: passive, position-sensitive, tunable by swapping bumpers. Used by Formula (Mod). Simpler to service. Firmer than ideal on slow deep compressions; softer than ideal on fast deep hits.
• Hybrid HBO + bumper: used by EXT (Storia) and some custom tunes. More tuning surface; more parts.

For an enduro-race bike on mixed terrain, HBO has the best fast/slow discrimination. For trail-only use, elastomer bumpers are genuinely competitive.

Lower LR helps in several ways: lower shaft velocity for a given wheel speed, lower force on the shock at any given wheel force, finer authority on the damping adjusters, and reduced air-spring heating per unit wheel travel. We share that preference.

The CP platform sits at 2.51-2.57, which is toward the upper end of reasonable for a 165mm bike. To go lower (~2.3 band) we would need either a longer shock (we are already at 230mm; 250mm pushes out of standard sizing) or a different linkage geometry with its own set of compromises.

A future progressive linkage variant is being explored — targeting approximately 2.9 at sag dropping to 2.5 at end stroke. That raises starting LR a bit, but delivers a progressive curve some riders prefer, as a deliberate trade-off.

Pedal kickback is the rearward rotation of the cranks when the suspension compresses. On a conventional pedal bike, the drivetrain has no active force opposing crank reversal — the full mechanical kickback angle is transmitted to the rider's feet.

With the Maxon BIKEDRIVE AIR S engaged, two effects reduce the felt kickback:

1. Drivetrain stiffness under motor torque. The motor delivers continuous forward torque (90Nm peak). The cranks cannot freely reverse — they must overcome the motor's forward drive force first.
2. Regenerative resistance during crank reversal. When the kickback force tries to drive the motor backward, back-EMF resists the reversal. Functionally, a mild regenerative braking effect — the motor absorbs the kickback impulse rather than transmitting it to the rider's feet.

Estimated reduction by assist mode:

• Eco: ~25-35% reduction -> ~2.0-2.5 deg felt
• Trail / Tour: ~40-50% reduction -> ~1.5-2.0 deg felt
• Boost / Sport: ~55-65% reduction -> ~1.0-1.5 deg felt

At trail/tour mode — where most riders spend most of their ride — felt kickback drops below any measurable rider sensitivity threshold under normal trail conditions. The CP platform eMTB's effective pedal kickback in everyday use is functionally zero.

To our knowledge no other eMTB manufacturer has documented or marketed this effect. Independent technical journalism is welcome to verify.

215 psi main chamber / 180 psi piggyback, two positive plus one negative volume spacer, baseline damping per the tuning guide. This is the configuration that delivers the 3.08x wheel-force ratio and the thermal performance described above. For other rider weights, scale main pressure approximately linearly (see the per-shock pressure table in the calculator above), keep piggyback ~15-20% below main, and start from the recommended spacer count for your weight.

Yes — both are under evaluation for the 2027 flagship. Reasons specific to the CP platform:

• Very large external air reservoir (Rover) directly addresses thermal load on multi-kilometre alpine descents — more gas volume = lower pressure rise per unit compression work = lower peak air temperature.
• Twin-tube damper architecture (Rover, Storia) separates compression and rebound oil paths more cleanly than a monotube, producing more consistent damping at high shaft velocities.
• Premium positioning consistent with where we want the flagship build to sit.

Practical hurdles: low volume (boutique supply for an OEM program needs negotiation), premium price (pushes the build into a higher tier), and a long tuning pass to validate against our kinematic before committing.