Forestal Siryon Diode in the test: Straight to test victory among the high-end enduro bikes
Peter Nilges
· 11.05.2025
The small Andorra-based brand Forestal is probably not on many people's radar, especially when it comes to mountain bikes without an electric motor. Together with the Cygnus marathon bike, the Siryon Diode is Forestal's first release without a motor. The single-pivot bike with banana swingarm looks very similar to the existing Siryon Neon light e-MTB. This bike has already caused a stir in E-MTB and shone with its potent chassis. We were therefore curious to see how the new Siryon enduro bike would fare in this comparison.
We have tested these bikes
- Forestal Siryon Diode 16.17 kg / 170/170 mm / 29" / 8899 Euro
- Lapierre Spicy 8.9 16.16 kg / 180/180 mm / 29/27.5" / 6999 Euro
- Merida One-Sixty 8000 15.61 kg / 170/170 mm / 29/27.5" / 7899 Euro
- Norco Sight C1 15.68 kg / 160/150 mm / 29" / 8499 Euro
- Propain Spindrift 5 CF 16.25 kg / 180/180 mm / 29" / 7029 Euro
- Scott Ransom 900 RC 15.46 kg / 170/170 mm / 29" / 9999 Euro
- Transition Sentinel Carbon 14.91 kg / 160/150 mm / 29" / 8990 Euro
Equipment Forestal Siryon Diode
- ForkFox 38 Grip X2 Factory
- DamperFloat X2 Factory
- Circuit / bandwidthSram X0 AXS Transmission / 520 %
- BrakesFormula Cura 4 / 203/180 mm
- ImpellersCrankbrothers Synthesis E
- TyresSchwalbe Albert Gravity Ultrasoft / Soft Radial 29 x 2.6
- Seat post / strokeOne Up / 180 mm
- max. system weight: 120 kg
- Guarantee: 7 years
- Special featuresFidlock holder and lock on the storage compartment
From the test lab
- Total weight16.17 kg without pedals
- Weight of wheels: 5927 g
- Impeller inertia5061 kg x cm²
Unusually ordinary
Visually, the Siryon stands out from the crowd of this test field and relies on a comparatively simple rear suspension concept. No high pivot with idler pulley, no floating pivot with a damper linked from both sides, not even a four-bar linkage. The Siryon comes as a supported single-pivot and has a massive banana swingarm that guides the rear wheel on a circular path. For greater rigidity and optimised kinematics, the swingarm is connected to the main frame via an additional rocker. Our stiffness test rig confirms that the Siryon has good stiffness on the main frame and a pleasant flex on the rear triangle. In our opinion, this is a perfect symbiosis of precision and directional stability at the front and a forgiving, high-traction rear end. The rear suspension performance of the enduro bike from Andorra also hits the mark.
The Siryon has the best rear suspension in comparison. The suspension works sensitively, but still has good travel, digests even big hits and offers the rider sufficient counter-pressure. Also surprisingly good: the traction of the single pivot when braking. In addition to the excellent chassis and perfect stiffness distribution, the geometry is well-balanced, conveying a great deal of safety and integrating the rider nicely between the wheels. What more could you want? Only the long chainstays prevent the Enduro from being easy on the rear wheel, but they do make it very stable at full throttle.
Uphill in the green zone
While the remarkably grippy Schwalbe radial tyres provide top traction downhill, they roll rather sluggishly uphill. At 76.5 degrees, the seat angle is already on the slack side in comparison and, together with the high front end and the somewhat strangely curved handlebars, requires an active weight shift when the going gets really steep. The Crankbrothers wheels are the heaviest in this comparison, which is somewhat detrimental to the acceleration. At 450 millimetres, the seat tube is relatively long. The standover height could also be better and leaves little room for manoeuvre.
BIKE summary of the Forestal Siryon
Forestal's debut model embodies the maximum enduro spirit and, with its exceptionally good chassis and balanced handling, comes out on top of the competition by a narrow margin. Test victory! - Max Fuchs, BIKE test editor
