Iuhu CP
Iuhu CP Frame Kit
“Truly optimal. You cannot ask for more. Outstanding work from Dirt Lab.”
— Fil Palmer (@ebikeitalia6832) — Independent kinematic analysis from sideview images — Anti-Rise measurement, Paratu CP / Iuhu CP platform, 2024
CP Chassis Observations (applies to Iuhu CP — same frame platform)
"Thanks to its low overall weight, the bike is easy to pop over root carpets and flick through direction changes."
— Ludwig Dohl, emtb-test.com / YouTube @ridebetterbikes — from his review of the Paratu CP (Iuhu CP shares the same CP frame platform, with lighter builds from ~13 kg)
"Whether you are trail-surfing on the way down, you don't hear a thing. You hear the trail, not the motor."
— Ludwig Dohl, emtb-test.com / @ridebetterbikes — on the CP platform's mechanical quietness (no pedal kickback, quiet drivetrain — applies identically to the pedal-only Iuhu CP)
Ludwig Dohl tested the Paratu CP eMTB. The Iuhu CP shares the CP frame platform and linkage but is pedal-only — so his observations on chassis weight, handling, and mechanical quietness apply directly to the Iuhu CP, while motor-specific observations do not.
Independently validated: ~100% anti-rise at sag | 97.3% anti-squat | 3.0–3.5° pedal kickback | K-Volve full analysis →
Carbon Enduro Frame Kit — Concentric Pivot
“Iuhu” means Pure Joy in the Taiwanese indigenous Bunun language, pronounced “YooHoo.” The same proven CP platform as the Paratu eMTB — without the motor. Pure enduro, pure pedal power.
The Iuhu CP is a full carbon monocoque enduro frame kit sharing the same silhouette, geometry, and kinematics as the Paratu CP eMTB. Same Concentric Pivot suspension design, same G-Volve geometry, same K-Volve kinematics — just without the engine system. At ~2,800 g, it is one of the lightest enduro frames you can buy. Factory to rider, no middlemen.
At a Glance
| Frame | Full carbon monocoque, ~2,800 g (size/color dependent) |
| Suspension | Concentric Pivot (CP) |
| Bottom Bracket | T47, 89.5 mm shell width |
| Head Angle | 63.9° at 150 mm fork · 63.7° at 160 mm fork · 63.5° at 170 mm fork |
| Seat Tube Angle | 77.8° at 150 mm fork · 77.6° at 160 mm fork · 77.5° at 170 mm fork |
| Rear Travel | 145 / 150 / 160 / 165 mm (230 mm eye-to-eye shock) |
| Fork Compatibility | 150–170 mm |
| Wheels | 29″/29″ or 29″/27.5″ mullet (geometry-preserving yoke flip chip) |
| Sizes | S / M / L — with RA Reach Adjust headset (±5 mm per size) |
| Derailleur Hanger | UDH (Universal Derailleur Hanger) |
| Downtube Storage | Integrated storage space with removable cover |
| Complete Bike Weight | From 16.9 kg (trail build) – 19.5 kg (full enduro coil) |
| Warranty | Lifetime frame (3 yrs carbon, original owner) · Crash-replacement for life · Second-owner goodwill after registration |
| Price | From $3,179 USD / €2$3,179 EU (frame kit) — free worldwide DDP shipping |
Descending: Concentric Pivot
CP stands for Concentric Pivot. The main pivot sits concentrically with the rear axle rather than in front of it. This completely isolates the suspension from braking forces, producing a bottomless feel that inspires confidence in steep, rough terrain.
Paired with a 63.5–63.9° head angle (varies by fork travel — 150 / 160 / 170 mm) and our K-Volve kinematics, the Iuhu CP is stable at speed, composed through chunk, and planted through corners — exactly what aggressive enduro riding demands.
Climbing: Featherweight Enduro
At ~2,800 g for the frame alone, the Iuhu CP is one of the lightest enduro frames available. Complete trail builds start at 16.9 kg — competitive with dedicated trail bikes while offering full enduro travel and geometry.
- T47 bottom bracket — stiff, lightweight, and widely compatible with modern cranksets
- 77.8° seat tube angle for efficient pedalling position
- Tuned anti-squat keeps the suspension firm under power without locking out
- Integrated downtube storage for tools, tube, or CO2 — no need for a pack
The Iuhu CP shares identical geometry and kinematics with the Paratu CP eMTB — so if you ever want to add a motor, the platform is already proven.
The DIRTLAB Formula
G-Volve Geometry
Long, not too low, and slack. 63.5–63.9° head angle (varies by rear travel config) × 77.8° STA. Balanced for speed on descents and efficient power transfer on climbs. Each size proportionally scaled, not just stretched.
Explore all travel and fork configurations in the interactive Geometry Calculator →
K-Volve Kinematics
Concentric Pivot layout eliminates brake interference. Anti-squat and anti-rise tuned for consistent suspension behaviour — firm under power, supple over impacts. Same performance across all sizes.
S-Volve Sizing
Each frame covers a range within its size. Our RA Reach Adjust headset system gives you ±5 mm of reach tuning — perfect for dialling in fit or bridging between sizes.
Make It Yours
- Travel: Four rear travel options (145/150/160/165 mm) via shock stroke length. Compatible with 150–170 mm forks.
- Wheels: 29″/29″ or mullet 29″/27.5″ via the geometry-preserving yoke flip chip.
- Reach: Fine-tune with the RA headset system — 0, -5, or +5 mm positions.
- Cable routing: Internal for clean looks, or external for easy serviceability.
- Colors: Standard finishes — Gloss UD, Matte UD, Gloss Black, Gloss Silver Metallic. Full custom Pantone colors: +$384 Single Solid / $494 Metallic / $604 Two-Tone — see Iuhu CP custom colours.
- Decals: Black or brushed rainbow silver (HRTF), applied under clearcoat.
Lead times
- Stock-colour Iuhu CP: 3–4 weeks based on current production.
- Custom-colour Iuhu CP: 5 weeks (confirmed CAD drawing + downpayment required to start).
Pick your rear travel
Four travel options on the same K-Volve / Concentric Pivot frame. Configured via shock stroke length — same eye-to-eye, different stroke. Pair with a 150 / 160 / 170 mm fork to dial the geometry.
Lightest possible build. Fast, flowy terrain. Pair with a 150 mm fork — head angle 63.9°.
The do-it-all setup. All-day trail, mixed terrain. Pair with a 150–160 mm fork.
Bottomless feel through chunk. Aggressive trail and enduro. Pair with a 160–170 mm fork.
Steep, fast, aggressive. Bike-park-leaning enduro. Pair with a 170 mm fork — head angle 63.5°.
Frame Kit Includes
- Full carbon CP frame (~2,800 g)
- RA Reach Adjust headset
- UDH hanger (Universal Derailleur Hanger)
- Internal cable routing kit
- Downtube storage cover
- T47 bottom bracket shell (89.5 mm)
The Iuhu Family
The Iuhu platform comes in multiple configurations for different riding styles:
Iuhu CP
Concentric Pivot enduro
145–165 mm rear travel
You are here
Frequently Asked Questions
What is the Iuhu CP?
How does it differ from the Paratu CP?
What's the kinematic performance?
What bottom bracket standard does it use?
What fork travel range does it take?
Does it support mullet?
What drivetrain works?
What is the frame warranty?
What is the crash replacement program?
Where is the Iuhu CP made?
Frequently Asked Questions
What is the Iuhu CP?
A full carbon enduro frame kit using the same Concentric Pivot suspension, geometry, and kinematics as the Paratu CP eMTB — but without the motor system. It is a pure pedal enduro frame at ~2,800 g.
What is a Concentric Pivot suspension?
The CP design places the main pivot concentrically with the rear axle. This completely isolates the suspension from braking forces, so the shock stays active and predictable whether you are on or off the brakes.
What is included in the frame kit?
Full carbon CP frame, RA Reach Adjust headset, UDH hanger, internal cable routing kit, downtube storage cover, and T47 bottom bracket shell. You add suspension, wheels, drivetrain, brakes, and cockpit to complete the build.
What bottom bracket does it use?
T47 with an 89.5 mm shell width. T47 is a threaded standard that combines the stiffness of press-fit with the serviceability of threaded — compatible with cranksets from SRAM, Shimano, Race Face, and others via standard T47 adapters.
Can I run it as a mullet (mixed wheel)?
Yes. The Iuhu CP supports 29″/29″ or 29″/27.5″ mullet via the geometry-preserving yoke flip chip. The flip chip adjusts BB height and head angle so geometry stays balanced in either configuration.
How much travel can I run?
The rear end accepts 145, 150, 160, or 165 mm of travel via a 230 mm eye-to-eye shock. Fork compatibility is 150–170 mm. This range covers everything from aggressive trail to full enduro.
What is the downtube storage?
An integrated compartment inside the downtube with a removable cover. Fits a spare tube, tyre levers, multi-tool, or CO2 cartridge — so you can ride without a pack.
What is the RA Reach Adjust headset?
A proprietary headset system with three positions: 0, −5, or +5 mm of reach adjustment. Fine-tune fit within your frame size or bridge between sizes without changing other geometry parameters.
What does DDP shipping mean?
Delivered Duty Paid. The price you see is the price you pay — we handle all import duties, taxes, and customs clearance. Free worldwide shipping on all frame kits. No surprise fees at your door.
Can I convert it to an eMTB later?
The Iuhu CP shares the same frame architecture as the Paratu CP. However, the motor integration requires factory-level work. If you want eMTB capability from the start, consider the Paratu CP with the Maxon Bikedrive AIR S system.
Build Your Iuhu CP
Frame kit from $3,179 USD / €2$3,179 EU • Custom Pantone colors available • Free worldwide DDP shipping
Independent Analysis
K-Volve in Action
Engineering at a Glance
K-Volve Kinematics
Five independently validated metrics. ~100% anti-rise at sag — the rear stays neutral under braking where every competitor rises. 97.3% anti-squat — no bob without lockout. 3.0–3.5° pedal kickback — below what most riders feel.
Full K-Volve analysis →G-Volve Geometry
Head angle and seat tube angle change with travel configuration. 63.9° at 145mm, 63.5° at 160mm. The 448mm chainstay is constant across all three sizes. Every angle is calculated before it is cut.
Full geometry tables →RA Reach Adjust
−5, 0, or +5mm of reach adjustment without changing any other geometry. 15mm of total adjustment within your frame size. No stem swap. No spacer stack. Included with every CP frame.
Full RA guide →Technology Deep-Dives
360° View & Gallery
High-resolution imagery and 360-degree viewer coming soon. Contact sales@bikelab-inc.com for current frame images.