With its Showa suspension, Pirelli tyres, new trellis frame and reasonable 226kg weight, the Zero SR/F handles as well most mid-sized roadsters.
But get too greedy with that addictive thrust and you’ll be looking for somewhere to recharge in as little as 50 miles. Ride it more modestly, on a mix of town and country roads, and it’ll manage around 75 miles. Stick inside the city limits and it lasts over 100 miles – but that does kinda defeat the point of having the SR/F’s performance.
Recharging time depends on how you plug it in. Use a regular three-pin plug and it takes four hours for a 95% charge. But find a three-phase power source, like some public charging stations, and this ‘Premium’ version’s more powerful onboard charger can cut that to just two hours.
The air-cooled AC motor, the biggest and most powerful Zero have used in a production bike, drives the rear wheel directly through a belt. The biggest improvement over previous Zero bikes is the larger, more powerful electric motor – rated at 110bhp and a whopping 140ftlb of torque. However, those impressive figures don’t translate directly into real-life speed as there’s no gearbox. The direct-drive, twist-and-go set-up means low-speed acceleration is muted, while top speed is capped at around 120mph – but in between, from 40mph-80mph, it’s extremely impressive.
The Zero SR/F seems well built and robust. There’s also a five-year warranty on the ‘power pack’ which should give some comfort.
The ‘Standard’ version is £18,045; this ‘Premium’ model (with a fly screen, heated grips and the powerful charger) is £20,045. Both are eligible for a £1500 government grant, taking that down to £16,545 and £18,545. However, the three-pin charging cable is considered a £445 extra, bringing the price back up to £16,990 or £18,990 (although it’s worth asking to get the cable thrown in for free). That’s a huge investment, but offset slightly over time by the rock-bottom running costs. A full charge is around £1.50 to £2.00, giving the equivalent cost-per-mile of a 300mpg petrol bike. Servicing is cheap too, as there are no fluids or filters to replace and no valve clearances to check.
Electric bikes with this level of performance tend to be about this price, although there are some cheaper electric scooters, such as the Super Soco TC Max (£4000), although that would struggle to top 50mph.
Instead of a petrol tank, there’s a lockable storage cubby hole – typically where you carry the charging cable – with a pair of built-in USB ports. A decent TFT display offers plenty of information, though your eyes stay glued to the ‘remaining range’ most of the time. The readout changes colour as you swap riding modes, too. There’s also traction control. The premium model also comes with a fly screen, heated grips and the powerful charger.
The SR/F uses Zero’s latest Cypher III operating system, featuring Bosch cornering ABS, traction control, and drag torque control from the motor. A specially-designed app allows the rider to customise their rider mode preferences, which consist of Sport, Eco, Street and Rain, as well as ten programmable options.
Sport is the most engaging, but requires a steady hand to prevent the battery draining rapidly. This proved to be problematic for the prototype on our 84-mile test, with the battery dropping from 90% to 25% after 50 miles of A-roads in Eco mode and the occasional twisty lane in Sport.