There is not much air between the tarmac and the pilot's seat. The fact that Scorpion riders immediately feel comfortable in the recumbent seat despite the low, semi-recumbent position is due to the sophisticated ergonomics of the pedelec trike. The handlebars and all controls are sensibly arranged and easy to reach. The wrists rest in padded supports, unencumbered by body weight. A generously dimensioned, central frame tube accommodates the cranks and Shimano drive unit well in front of the rider. It is designed as a telescopic tube and can be easily adjusted to the rider's leg length using a quick release. The chain length adjusts automatically. This means that riders from 150 to 200 centimetres tall can cope with the universal frame. When sitting on the comfortable seat, the "Tadpole" construction is stable on its wheels. Tadpole is what the recumbent scene calls such three-track recumbents with two steered wheels in front of the rider.
Not only does this tadpole differ significantly from single-track bikes in terms of driving dynamics, it is also much more elaborately designed. The MacPherson wheel suspension on the front axle is derived directly from automotive engineering. Elastomer struts act as dampers, while a stabiliser improves cornering behaviour at the limit. Tie rods transmit steering impulses to the front wheels, just like in a car. A sprung swing arm at the rear completes the Scorpion's chassis. A good solution: the pannier struts on both sides are attached to the main frame and are therefore part of the suspended mass. This improves handling characteristics and comfort, even with heavy luggage.
Dynamic and safe
The Scorpion reacts promptly and predictably to steering impulses, it steers intuitively and directly. Because the pelvis and upper body are supported on the seat, the legs build up a lot of pedalling pressure with subjectively little effort. With a maximum torque of 60 Nm, the drive produces enough additional thrust for dynamic riding pleasure. 25 kilometres per hour are quickly reached, and the Scorpion can be accelerated further on flat terrain with a manageable amount of effort. The electromechanical Nexus gear hub changes its eight gears at the touch of a button, with the option of automatic shifting. During our test rides, it sometimes unintentionally skipped several gears in automatic mode. The three-wheeler masters high cornering speeds without any tendency to swerve thanks to its low centre of gravity.
Both front wheels remain securely on the ground even during fast cornering - the Scorpion would easily survive a moose test. Fast, tight cornering radii generate high centrifugal forces, but the ergonomically shaped, adjustable reclining seat offers sufficient support. Mechanical disc brakes on both front wheels stop the Scorpion safely at all times, the braking performance is significantly higher than that of single-track bikes. The fact that each of the brake levers controls a different front wheel is irritating in theory, but has no noticeable effect on the steering. On request, there is also a hydraulic brake system with just one brake lever that acts synchronously on both front wheels. There is only a parking brake on the rear wheel. All the controls for the gear hub and engine management are easily accessible at the right-hand end of the handlebars. With a distance of 46 centimetres between the seat and the road, our test bike is a moderate version of the Scorpion fleet.
The lowest model sits 43 centimetres above the tarmac, while the rehab version for riders with physical disabilities is 57 centimetres. Incidentally, tall seat heights cause one of the few disadvantages of the Scorpion: to compensate for the dynamic disadvantage of the higher centre of gravity, the designers increased the track width. With an overall width of 92 centimetres, our test bike could no longer fit through a standard door.
You can read the full test report of the HP Velotechnik Scorpion Plus 26 in MYBIKE 4/2021.
