Jekyll

mtb3450–6249 USD

Origin

Cannondale's enduro/gravity machine — built for descending above all else. 'Jekyll was born for the downs.'

Specifications

Frame: Full carbon — carbon front and rear triangles. High-pivot 4-bar Horst Link with Guidler idler, Gravity Cavity shock in downtube, Proportional Response kinematics, size-specific chainstays, BSA-73 BB, ISCG05 tabs, Ai Offset rear spacing.
Weight: kg
Drivetrain: Jekyll 1: SRAM GX Eagle 1×12 (GX Lunar derailleur, 10-52T XG-1275, X1 30T crank). Jekyll 2: Shimano Deore M6100 1×12 (10-51T, Deore 6120 30T crank).
Brakes: Jekyll 1: SRAM Code RSC 4-piston, 220mm front / 200mm rear CenterLine rotors. Jekyll 2: Shimano M6120 4-piston, 203/203mm RT64 rotors.
Wheels: 29" both ends. Jekyll 1: WTB KOM Trail i30 TCS (30mm inner, 32h, tubeless), Formula front / SRAM MTH 700 12x148mm Ai Offset rear (XD). Jekyll 2: WTB STX i30 TCS, Shimano MT400/MT410 hubs (Micro Spline).

The verdict

+Strengths

Beta MTB: 'Ridiculously stable' at speed — more planted than equivalent non-high-pivot bikes with same numbers
Beta MTB: 'One of the most confident-feeling long-travel 29ers' on high-speed open descents
Flow MTB: 'Exceptionally well-rounded performance', 'chassis, suspension and geometry absolutely dialled'
Flow MTB: 'Impressively neutral when pedalling through choppy rock gardens' — Guidler does isolate suspension
ENDURO Mag: 'Intuitive handling and excellent composure at high speeds'
SRAM Code RSC brakes on Jekyll 1 — 220/200mm rotors, tool-free reach adjust. Top-spec enduro stopping
Maxxis Assegai + Minion DHR II front/rear — optimal enduro tire combo
BSA-73 + ISCG05 standard — good serviceability for a niche bike

−Weaknesses

ENDURO Mag 2022 group test: Jekyll = worst climber alongside Nukeproof Giga. Shock sinks deep uphill, forces forward weight transfer
ENDURO Mag: 'Significant pedal bob' on climbs — costs efficiency
Flow MTB: 'Not most spirited bike on uphills — generous weight, aggressive rubber, active suspension'
Flow MTB: Stock WTB wheels 'particularly cheap' on Jekyll 2. Rear wheel suffered spoke tension loss, dings
Flow MTB: Dropper post too short for large frame (150mm — needs 175mm+)
Ai Offset rear spacing: non-standard. Rear wheel replacement limited to Ai-compatible hubs
ENDURO Mag 2022: Guidler grinding noise when pedalling — chain lube critical
Jekyll 2 dropper: TranzX 150mm — Flow MTB wishes for longer + DoubleDown rear tire
Jekyll not suited for Baltic terrain: no DH/enduro race infrastructure, no bike parks, no shuttles

Did you know

01Guidler: concentric to main pivot, so chain doesn't grow as rear wheel travels. Drag measured as negligible by Cannondale on instrumented hardtail (Loam Wolf, citing engineer).
02Gravity Cavity: shock inside downtube = lowest possible center of gravity. Beta MTB: bike frequently mistaken for e-bike because of the bulky cavity.
03Mid-high pivot: NOT a pure single-pivot high-pivot. Cannondale kept Horst Link for active braking performance. Axle path rearward but arches forward at bottom-out — preserves some agility.
04Proportional Response extends to leverage curves: small frames 13% progression, XL frames 20% — heavier/taller riders get more support.
05Chainstays grow per size AND the kinematics change per size — both optimized simultaneously.
06velo.clubbers.ee: only 2 Jekyll mentions, both from 2003 about original Jekyll 3000 with Lefty Carbon ELO. Zero community presence for modern Jekyll in Baltics — very niche bike.
07Jekyll is only 2 variants deep — no budget alloy option. Carbon frame comes as minimum entry.
08Ai Offset rear spacing: non-standard hub spacing retained from older Cannondale platform. Complicates rear wheel sourcing.

Who it’s for

Enduro racers wanting unconventional suspension advantageGravity riders (bike park, steep tech descents)Riders who primarily descend and accept climbing compromise