How to use the Bosch Range Assistant

If you have an electric bike equipped with a Bosch motor, the Bosch Range Assistant is a useful tool to help you work out what range you can expect from your battery.

Trying to give riders a precise answer to the question: What is the range of my battery? is a difficult one to answer as many factors affect the range of all ebike batteries, not just Bosch. Such things as the modes you are using, the motor, the terrain, the road surface, air temperature, rider weight, tyre tread & pressure. The Bosch eBike Range Assistant attempts to calculate a predicted range for you based on parameters you set. Let’s take a look.

Assisted vs Total

It’s important to point out that the calculator will only give you an estimated ‘assisted’ range. There will be times on a ride when you don’t pedal when rolling downhill, for example, or you may pedal but above the 15.5mph threshold when the motor assistance stops. This additional mileage is not taken into account so the total distance of a ride will almost always be greater than the assisted range the calculator predicts for you.

For questions around Ebike Battery care, take a look at our FAQs page


First up let’s set some details about the rider. On the right hand side of the screen are three tabs: Rider, eBike, Environment. If you select the Rider tab, you will see you are able to set the Total weight and Cadence.

Total Weight

In Kilograms, add up your own body weight, your bike weight and anything else you or the bike will be carrying like panniers, rucksacks etc. For example, if you take an 80kg rider on a Raleigh Motus Ebike (average bike weight 25kg) + a pannier bag and contents (approx. 10kg). You would set the slider to 80+25+10=115kg.

Tip: If you don’t know the weight of your bike, call us, weigh it yourself or take a look on the manufacturers website


Cadence is simply how fast you pedal measured in revolutions per minute (rpm). The calculator defaults to 60rpm or one crank revolution per second which is a bit slow in my opinion. Most riders average between 70-90rpm usually so 80 is a good starting point.

Tip: If your ebike display has a cadence function, use that to work out how fast you pedal on average along a flat, straight road for a few hundred metres. If it doesn’t I recommend 80-85rpm.


The middle tab is eBike and allows you to set some specific parameters about the type of electric bike you have.


This is a simple answer to a simple question. Do you have a Bosch Smart System installed on your bike or not? Select System 2 if you don’t. If you are unsure you can use the Bosch website to identify if you do, take a look at your bike manufacturers website or just call us.


The Drive option allows you to select your Bosch motor. Simply click on the arrow either side of the motor image to scroll through the choices. Your options are:

Bosch Smart System
  • Bosch Active Line
  • Bosch Active Line Plus
  • Bosch Cargo Line
  • Bosch Performance Line
  • Bosch Performance Line Speed
  • Bosch Performance Line SX
  • Bosch Performance Line CX
  • Bosch Performance Line CX Race
Bosch System 2
  • Bosch Active Line
  • Bosch Active Line Plus
  • Bosch Cargo Line
  • Bosch Performance Line
  • Bosch Performance Line Speed


It is really important you choose the right battery. This is literally your fuel tank and we are trying to work out how many miles it will take you so pay attention to this one. Your options are:

Bosch Smart System
  • PowerPack 400 Frame
  • PowerPack 545 Frame
  • PowerPack 725 Frame
  • CompactTube 400
  • PowerTube 500
  • PowerTube 625
  • PowerTube 750
  • PowerPack 400 Rack
  • PowerPack 500 Rack

PowerPack back batteries sit externally on your frame or rack whereas ‘Tube’ batteries are in-frame usually accessed by a cover. PowerTube and CompactTube also have the ability to be coupled with a range extender. If you have one of these, when you choose a ‘Tube’ battery the Range Extender option will become available to select underneath the battery choice. Enable it to select the Bosch PowerMore 250 extender under the Additional Battery option.

Bosch Smart System Range Extender option enabled
Bosch System 2
  • PowerPack 300 Frame
  • PowerPack 400 Frame
  • PowerPack 500 Frame
  • PowerTube 500
  • PowerTube 625

The Bosch System 2 allows dual batteries of different capacities and types to be used. If you enable this option, the dual battery configurations allowed will be displayed. Your choices are:

  • PowerPack 400/400
  • PowerPack 400/500
  • PowerPack 500/500
  • PowerPack 400/PowerTube 500
  • PowerPack 400/PowerTube 625
  • PowerPack 500/PowerTube 500
  • PowerPack 400/PowerTube 625
  • PowerTube 500/500
  • PowerTube 500/625
  • PowerTube 625/625
Bosch System 2 Dual Battery option enabled

Type of Bicycle

For this option simply select the type of bike that best describes the type of electric bike you have. Your options are:
I’ve added some notes to try and help you understand each type better

  • Athletic Touring Bike / MTB (Touring or Trekking Bike e.g. Cube Touring, Kathmandu, Haibike Trekking)
  • Upright Road Bike (Flat bar road bike, skinny tyres e.g. Raleigh Trace)
  • Low Road Bike (Drop bar Road or Gravel Bike e.g. Lapierre E-Crosshill)
  • eMTB (Mountain Bike)
  • City Bike (Lighter version of the Athletic Touring Bike e.g. Raleigh Motus)
  • Cargo Bike (Longtail or Box)

Tire (Tyre) Tread

It’s not a spelling mistake. If you didn’t know, Europe and elsewhere around the world spell tyres with an i instead of a y. No idea why. Maybe Wikipedia can explain.

For this option select the type of tyre you have. Width has a part to play in calculating range as wider tyres have a higher rolling resistance but you don’t get to be that granular here. Just choose the option that is closest to what you have. Your choices are:

  • Hybrid Bike Tires (tread, typically 35-50mm wide)
  • MTB Tyres (Cross Country) (knobbly, typically 2.1 – 2.5 inches, some gravel bike tyres may be wide enough)
  • Road Bike Tires (slick, typically 25-35mm wide)
  • City Bike Tires (almost slick or fine tread, wide, typically 45-60mm wide)
  • MTB Tires (Enduro) (heavy, big, knobbly, typically 2.4 inches+)

Find out more about electric bike wheel sizes here

Shifting System

Does your bike have derailleur or hub gears? If you are not sure then my article on the differences between the two systems will help you.

  • Derailleur
  • Hub Gear
Derailleur Gears
Hub Gear


The Environment tab takes information on how and where you will ride so it can try to work out what external factors on the bike will affect the range calculation. These all affect the range, some more than others, so it’s important you try to be as accurate as possible.


Are you going to be riding in the hills, on pan flat roads or a bit of both? Hillier routes require more effort and consequently more assistance so range will be compromised. Your choices are:

  • Hilly
  • Uplands
  • Mountainous Tour
  • Flat
  • Some inclines


The surface you ride on matters because of the rolling resistance it generates. Riding offroad requires more effort than on smooth tarmac (asphalt) so more assistance is required. Your choices are:

  • Road with poor quality
  • Gravel and surfaced forest paths
  • Dirt Forest and field paths
  • Soft forest paths
  • Mostly good asphalt

Wind Conditions

We all hate riding into the wind. On an electric bike it is definitely easier but at the expense of additional assistance and battery. Your Bosch Range Assistant choices are:

  • Light breezes
  • Moderately windy
  • Very windy
  • Stormy
  • Windless


What time of year are your riding? Air temperatures can affect the capacity of a battery and therefore your range. Li-ion batteries don’t like extreme cold or heat. Find out more about ebike batteries with my FAQ article. Your choices are:

  • Winter
  • Summer

Starting Up

The Starting up slider tries to gauge how much you will stop and start on your rides. You have 5 levels to choose from which range from Level 1 – rarely to Level 5 – Frequently

Take your time with the Environment options

Play Time

With your Rider, eBike and Environment data keyed in you can now play with the Range Assistant. At the top of the calculator screen you have an Average Speed slider, you can choose your Riding mode and in the blue box the estimated range is displayed based on all the data you have entered. Move the slider to select whether you want the speed and distance to be displayed in miles or km.

Average Speed

If you move the Average Speed slider to the right, the speed will increase and you will see the estimated range go down. Higher average speeds require more pedal assistance therefore more power is drawn from the battery and range is compromised.

Riding Mode

Riding Modes mirror the options you have on the head unit on your electric bike. Off and Eco are the lowest modes that give you least assistance. As you select modes to the right the amount of assistance delivered by the motor increases right up to Turbo, the highest mode. Higher modes require more power and more battery power so you will see as you select a higher mode the estimated range figure the Bosch Range Assistant calculates will go down.

The animation of Mr Stick Man riding a bike will change based on the data you enter. It is simply an attempt to visualise the options you have chosen. For example, more wind means fast leaves blowing past, Winter means snow and so on.

It’s a Guesstimation

The Bosch Range Assistant is a great tool if you are trying to work out if you will have enough battery for a long ride or if you want to compare different motors and batteries in bikes, for example. You can see from what I have described, there are many variables to play with BUT remember!

  1. It’s always an educated guess
  2. It’s only a guide
  3. It’s NOT absolute or real

That doesn’t mean it’s not useful though. I use it all the time with customers and I’ve used it to compare non-Bosch motors too. Just remember every rider on every electric bike on any ride is a unique set of circumstances and therefore is almost impossible to predict or give you a precise answer what the range will be.

TIP: From my experience I’ve found the calculator tends to over play what range you could get by around 10-20%. Why wouldn’t it? It’s Bosch trying to tell you how good their ebike systems are. For me, if a range is, say, 100 miles I’ll take 15% off and go with 85 miles. I’m confident that’s pretty close and I can honestly say I’ve never had any customer ever come back to me and say I was wrong or they ran out of battery.

That rolls up my guide on the Bosch Range Assistant. Have fun with it and if you have any questions just drop us a line.

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