Shimano STEPS: components explained

E-bike drive unit, battery, drivetrain and display

With the constant improvements in motor and battery technology, electric bikes are becoming more popular. A number of brands have already jumped on the e-bike bandwagon and that number's set to increase as more powertrain options become available. Shimano's STEPS is one such option. 

Rather than merely adding a battery and motor to an existing groupset, the Japanese component giant has designed the electric system from the ground up. We’ve gathered together all the info we can find on Shimano's STEPS components to compile this guide. 

What is Shimano STEPS? 

STEPS, which stands for Shimano Total Electric Power System, is Shimano's range of electric bike (or e-bike) components. Like other e-bike systems, such as those from Bosch, it's a pedal-assist system, which means the power is only applied when you're pedalling. It's designed to make e-bikes feel and handle more like 'normal' bikes while combining user-friendliness with a clean design.

There are numerous regulations concerning electric bikes, particularly governing power output and speed, so as to differentiate them from electric motorbikes and scooters. In the UK this includes EN 15194 for EPAC (Electronically Power Assisted Cycles) and EU regulation 168/2013, which state that the power output must not exceed 250 Watts, and that the maximum assisted speed will not exceed 25kmph (15.5 mph). 

The benefits of electric bikes

Shimano has designed STEPS with two types of users in mind. The first is city riders, who either can't drive or want to save money on their commute by cycling, but don't want to arrive at their destination hot and sweaty. The second group, trekking and leisure riders, is one of the key user groups for e-bikes. These are cyclists who want to be able to ride further, more easily, and keep up with fitter riding companions.

The main benefits of any pedal-assist e-bike system include:

  • A power boost to make hills easier to climb
  • Extra drive to combat the slowing effects of headwinds
  • The ability to cover greater distances with less fatigue (depending on battery life)

What does Shimano STEPS consist of?  

The STEPS drive unit

The shimano steps drive unit:
The shimano steps drive unit:

The system includes a 250W, 36-volt electric drive unit, or motor, that will help get you up to speed, but cuts out at 15.5mph (25km/h). You can go faster than that if you want but any speeds over 15.5mph have to be generated by either pedalling or gravity alone.

The drive unit produces a maximum torque of 50nm and according to Shimano, weighs 3.2kg, making it one of the lightest on the market. There are a number of sensors incorporated into the unit to monitor torque, cadence, braking and speed, and, like the battery, it's available in black or grey. 

The STEPS battery

The shimano steps battery can be mounted on the down tube or above the rear wheel:
The shimano steps battery can be mounted on the down tube or above the rear wheel:

The current incarnation of the Shimano STEPS system has a 400W-capacity lithium-ion battery, though Shimano has said it will shortly be releasing a 500W version that offers 20 more percent power. The battery can be mounted on the frame's downtube or on a rack (approx 2.6kg) attached to the rear of the bike.

It'll take four hours to give the battery a full charge but only two hours to fill it up to 80 percent. Shimano expects the battery to be good for 1,000 charge cycles, which should equate to around 37,000 miles of riding, although this will depend on how much you use the power assist. The STEPS battery can be charged on or off the bike and a new one will cost £360. 

The STEPS drivetrain

Rider-generated power comes through a single-ring chainset that uses either a 38- or 44-tooth chainring and has 170mm or 175mm cranks. The chainset is compatible with 8, 9, 10 and 11-speed hub or derailleur gear systems and comes with a chainring cover, so there's no need to wear bicycle clips or roll up your trouser leg. 

As well as taking the effort out of pedalling, STEPS can lend a hand with shifting too. With the Di2 Nexus hub-gear set-up you can opt for a 'manual' version and change gear by pressing buttons, or go choose the 'automatic' option and let STEPS decide when to change gear for you. The automatic version uses a 'Symptomatic shifting system' that senses your cadence and power output, and shifts gears to match them. You can fine-tune the system's sensitivity so that the shifting occurs at specified cadences. And should you come to a stop while using the system, it'll automatically shift down so that you're in an appropriate gear when you set off again.

But if it all becomes too much and you find yourself with no option but to get off and push, there's also a 'walk assist' mode that provides a small amount of drive to make life a little bit easier, which could be particularly useful should you find yourself lugging a bike loaded down with groceries up a steep hill. 

The STEPS display

Shimano steps: the dedicated computer displays battery and range information:
Shimano steps: the dedicated computer displays battery and range information:
A dedicated computer keeps track of battery life

Included in the STEPS system is a bar-mounted display that shows all the usual info you'd expect with a bike computer, including speed, trip distance, elapsed time and so on, as well as what mode the STEPS system is currently in, the estimated range left in the battery and what gear you've selected. 

The computer is more than just a passive tracking device, however. It analyses the data you generate as you ride the bike and will use this to increase the accuracy of it's projections for the estimated range left in the battery.

Bikes that feature Shimano STEPS

There are a number of brands already producing hybrid, commuter and mountain bikes that use Shimano STEPS. In the UK, Ridgeback offers the Electron (£1,999.99) and Electron+ (£2,199.99), a pair of power-assisted step-through city bikes; Saracen has the robust-looking Juiced urban bike (£2,599.99); while Raleigh and Whyte produce the Strada E (£2,000) and Coniston (£1,999) city bikes respectively.

You can find shimano steps on raleigh's strada e city bike for £2,000:
You can find shimano steps on raleigh's strada e city bike for £2,000:

Raleigh's Strada E city bikes gets power assist from Shimano STEPS 

Most of the bike industry's biggest names supply the international market with ebikes and among those specced with Shimano STEPS are the Cannonade Kinneto and Trek Lift+. Merida also has a range of touring bikes (E-Pressso) and MTBs (Big Seven) equipped with STEPS.

Shimano STEPS E8000 mountain bike groupset

Shimano has also produced the STEPS E8000, an e-mountain bike groupset designed for all-mountain, trail and cross-country use. It's been designed specifically for mountain bike use and provides more torque assist at lower cadences to help with sharp climbs. 
At 70nm maximum torque, it provides more power than the leisure/commuter version of the STEPS system and compatibility with Shimano's Di2 mountain bike groupset. 
This article was published by BikeRadar, the world's leading source of bike reviews, gear reviews, riding advice and route information
  • Discipline: Road, Mountain, Urban, Womens
  • Location: UK, USA, Australia

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