Thursday, 19 January 2017

Tech Talk: Specialized Turbo Levo FSR

Specialized Turbo Levo FSR

In terms of design alone, the Specialized Turbo Levo FSR is light years ahead of other e-bikes. With its battery pack concealed inside the down tube it looks like a conventional Stumpy on steroids, which is why it’s affectionately known as the Hulk. There’s no handlebar display either, so that’s one less thing to break. Instead, you control the three levels of power output (Turbo, Trail and Eco) with +/- buttons on the side of the down tube, where an LED display lets you know which mode you are in and how much battery life is left. A centre button powers up the battery with 10 LEDs showing current battery charge. Two buttons on either side of the power button take you up or down in electric assist and the LEDs show your mode when changing it, then the LEDs revert back to indicating battery life.

Mode button and battery life indicator

The system needs to read two things to engage, speed at the wheel and torque at the crank. The speed sensor is hidden behind the non-driveside dropout, the magnet mounted on two disc rotor bolts rather than a spoke. Why has Specialized gone to such lengths to do this? Simple. If the magnet for the speed sensor gets damaged or twists on a spoke the motor stops delivering electrical assistance and no one wants that on a 23.33kg bike. To measure torque, the system has a built in power meter. Using those and the mode selected, it essentially matches your effort. You pedal harder, the system outputs more. When coasting the system is off. 

Mission Control App

More complex controls are all managed with a phone app called Mission Control. Using the Bluetooth connectivity of the system’s brain located in the battery, Android and iOS users can adjust the level of assist in each mode, tune how quickly the assist is delivered, change modes, and run diagnostics on the battery and motor. The app also connects to Strava allowing you to automatically upload rides, even tagging them as e-bike rides. The app also provides a setting called Smart Control where the rider inputs parameters based on duration or distance and preferred remaining battery life at ride’s end. By checking in with your phone every 10 seconds, the system will automatically adjust its level of output. Mission Control also displays battery and motor health, number of charge cycles performed and an odometer for the motor. 

Specialized also worked with Garmin to allow Edge 1000, Edge 520 and Edge Explore 1000 users to pair with the Turbo Levo. Through Garmin’s Connect IQ app store, users can download a Specialized app that then displays assist mode, battery life, cadence, speed and power on screen. It also allows you to change assist modes on the Garmin’s touchscreen instead of reaching down to the bike’s down tube buttons. For further ergonomic enhancement, Garmin’s Edge remote can be used to toggle between Turbo, Trail and Eco modes. 

If you don’t have a newer Garmin, Specialized still has you covered. In the Mission Control app, you can use a “fake channel” to display battery life using ANT+. It will show up in your cadence or power window, depending on what you select. Battery charge time is three and a half hours from a completely flat battery to full. The custom lithium-ion battery is designed for 700 charge cycles, charging from empty to full. So, that’s nearly two years of riding every day using the battery completely each time out. Battery run times will depend on the modes used, rider weight and terrain, but typically 5,000 feet of elevation gain per charge is possible.

Only need a hex key to attach the battery

It is classified by the federal government (USA) as a low-speed electric bicycle and as such is limited to 20 mph with a maximum electric power output of 750 watts. This bike only offers a maximum of 530 watts, and an average of 250 watts when you apply force to the pedals. Assuming that the enthusiast cyclist produces about 200 watts, riding in Turbo mode is like the equivalent of having a ghost stoker on board providing an extra 250 watts of power. Trail and Eco modes both offer less assist and are independently adjustable with a smartphone app.

The downsides to the e-mountain bike seem just as clear as the benefits. Even though the Turbo Levo seems to be the best of its breed right now, it's still a heavier and more complicated machine than a regular bike. Technology will undoubtedly improve this area, but for now it’s what we’ve got. Pedaling it without power is as hard as you think. 

  • 3 mode to assist your pedalling
  • Clean and stealth look
  • Tune it with app in your smartphone
  • 530 watts ready to boost your speed
  • Connectivity with Garmin and Strava


Downtube: The down tube connects the head tube to the bottom bracket shell. 


Ride On!

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