Karhu Synchron Ortix F100329 - Stability Wide Fit for Pronators
The Karhu Synchron Ortix are stability running shoes designed specifically for runners with pronation and wide feet, thanks to 1.3 million 3D scans that have defined the most anatomical wide fit on the market.
Fulcrum Technology for Biomechanical Efficiency
The patented Karhu Fulcrum system positions the propulsion point 1.5cm further forward than traditional shoes, reducing stress on the Achilles tendon and calf by 12% during the propulsive phase. Ideal for long training runs and active recovery.
Pronation Control Without Rigidity
Progressive medial support that corrects overpronation without restricting the foot's natural movement. Tested on 500+ runners with moderate-to-severe pronation, it reduces ankle collapse by 18% compared to neutral shoes.
Anatomical Wide Fit: 1.3M 3D Scans
Upper constructed based on 1.3 million 3D scans of real feet, guaranteeing an extra 4mm in forefoot width without compromising heel lockdown. Eliminates pressure points on bunions and metatarsals.
Technical Specifications
Weight: 360g (US size 9) - ideal balance between support and agility
Drop: 5mm - natural heel-to-toe transition
Midsole: Dual-density AeroFoam with a stiffer medial zone
Upper: Breathable Air Mesh with TPU reinforcements on the arch
Outsole: M-Lock Rubber, high abrasion, grip on wet asphalt
Who It's Ideal For
✓ Runners with pronation seeking support without excessive rigidity ✓ Wide feet (E/2E width) who struggle with standard shoes ✓ Training runs 10-25km on asphalt and compact dirt roads ✓ Runner weight 70-95kg - cushioning calibrated for medium-to-high impacts
When NOT to Choose Them
✗ Neutral/supinator feet: medial support would be counterproductive ✗ Races under 10km: prioritize lighter racing shoes ✗ Technical trail: insufficient tread for mud and rocks
Maintenance and Durability
Washing: hand wash in cold water, no machine washing (degrades medial support). Natural drying away from heat sources. Durability: 600-800km before the midsole loses 20% of its responsiveness. Rotation with neutral shoes is recommended to vary biomechanical stimulation.
Finnish Heritage Since 1916
Karhu ("bear" in Finnish) is the brand that invented the Fulcrum in 2006, after 90 years of experience in sports footwear. Every model is tested in the extreme conditions of Finnish Lapland.
Recommended Pairings
Complete your setup with Falke RU4 anti-blister running socks (heel/toe reinforcement) and Superfeet Green insoles for high arches. For intense training, consider the Karhu Ikoni 2024 (neutral, 280g) as rotation shoes.
Color: Pigeon/Stormy Sea - pigeon grey with stormy blue accents, 3M reflective on heel.
