BH iRS1: A lightweight e-racer weighing 12.9 kilos with a peak power output of 700 watts

Our verdict on the iRS1 bra

With the iRS1, BH is really pushing the boundaries. The high-output motor and 810 Wh battery capacity are well beyond the norm. It’s a very ambitious goal for the Spanish manufacturer to keep the weight of this top-of-the-range model under 13 kilos given these specifications.

The new SEG engine: a powerhouse in a small package

According to BH, the new SEG-BLM motor was developed by SEG Automotive and manufactured in Spain. According to the manufacturer, the motor weighs 2.1 kilograms, has a maximum power output of 700 watts and delivers up to 80 Nm of torque. Torque, cadence and speed sensors are said to operate at a sampling rate of up to 1,000 Hz. BH promises that this will result in progressive and natural power delivery.

The power supply is the same across all iRS1 models. The battery, which is permanently integrated into the down tube, has a capacity of 630 Wh. This includes, as standard, a 180 Wh XPro battery, which is mounted on the frame in the shape of a water bottle. BH states a range of up to 150 kilometres with the internal battery and up to 190 kilometres with both power packs. For long rides in mountainous terrain, the high nominal capacity is likely to be a decisive factor, particularly as the additional battery can be removed whilst on the move or charged separately.

For the frame, BH has opted for carbon on the three higher-end models. Tube shapes based on the Kamm-Tail principle and a redesigned fork are designed to reduce aerodynamic drag. The carbon models can accommodate 32-millimetre-wide tyres. This enhances comfort and grip on rough tarmac. BH states that the top-of-the-range Carbon 1.6 model has a total weight of just 12.9 kilograms.

The geometry is designed with comfort in mind, whilst the short chainstays are intended to enhance agility. Modern features include integrated cable routing, the UDH derailleur hanger and 12 mm thru-axles.

The bike is operated via a display integrated into the top tube and wired iButtons on the handlebars. The display shows, amongst other things, speed, assistance level, range, power, cadence and torque. According to the manufacturer, five parameters per assistance profile can be adjusted via the SEG app. Bluetooth LE heart rate sensors can also be integrated.

The range starts at 3,699 euros for the iRS1 1.2 with an aluminium frame and mechanical Shimano 105 gears. The Carbon 1.6 costs €6,999 and combines Shimano Ultegra Di2 with Vision TC45 carbon wheels.

Key information about the iRS1 bra

• Drive: SEG BLM mid-drive motor with up to 700 W peak power and 80 Nm torque
• Engine weight: 2.1 kg
• Battery system: 630 Wh down tube battery plus 180 Wh XPro auxiliary battery
• Total capacity: Up to 810 Wh
• Ground clearance: Up to 32 mm on the carbon models
• Instructions: Top tube display, iButtons on the handlebars and app connectivity
• Frame: Carbon fibre on the 1.6, 1.5 and 1.4; aluminium on the 1.2
• Price range: 3,699 to 6,999 euros

An overview of the model variants