Every electric bike is sold on a range number, and every range number is measured under conditions you will almost never ride in. This is not a scandal, it is just how the industry tests. But it means a bike advertised at 100 miles might give you 45, and nobody warned you.
Here is how to read those numbers, and how to work out what you will actually get.
The only figure that matters: watt-hours
Ignore the marketing headline for a moment and find the battery capacity in watt-hours (Wh). If a bike lists volts and amp-hours instead, multiply them: a 52V 20Ah battery is 52 × 20 = 1040Wh.
Watt-hours are the size of the fuel tank. Everything else is fuel consumption.
A useful rule of thumb for a fat-tire electric bike with a rider of average weight:
- Low assist, flat ground, pedalling properly: around 10 to 15 Wh per mile
- Medium assist, mixed terrain, some hills: around 18 to 25 Wh per mile
- Full throttle, no pedalling, heavy rider or cargo: 30 to 45 Wh per mile
So a 1040Wh battery gives roughly 70 to 100 miles at the gentle end, around 40 to 55 miles in normal mixed riding, and 25 to 35 miles if you ride it like a scooter. All three of those are true statements about the same bike. The manufacturer quotes the first one.
What actually drains the battery
Your weight, and what you are carrying
This is the single biggest factor and the one test conditions are most optimistic about. Every extra 50 lb of rider, passenger or cargo costs you meaningful range. A 250 lb rider with panniers will not see the same number as a 150 lb rider on an empty bike.
How much you actually pedal
Throttle-only riding can double or triple consumption compared with pedalling in low assist. On bikes with a cadence sensor, the motor gives a fixed amount of help as soon as the pedals turn; on a torque sensor it gives help in proportion to your effort, which is usually more efficient.
Hills, wind and stopping
Climbing costs energy and you never get it back. Every stop and restart costs energy too, which is why city riding with traffic lights uses more than an uninterrupted country road at the same speed.
Cold
Lithium batteries lose usable capacity in the cold. At around freezing, expect roughly 20 to 30% less range than the same ride in mild weather. The capacity comes back when the battery warms up: it is not damage, just chemistry.
Tyre pressure
The cheapest range you will ever buy. Fat tyres run at low pressure and lose air steadily. Under-inflated tyres can cost you 10 to 15% of your range. Check them fortnightly.
What to expect from each Roots Rider model
These are the manufacturer's claimed figures, followed by a realistic mixed-riding estimate for a rider of average weight using medium assist.
| Model | Battery | Claimed range | Realistic mixed riding |
|---|---|---|---|
| Cheetah 2 Pro | 1440Wh | up to 100 mi | roughly 55 to 70 mi |
| Cougar Pro | 1200Wh | up to 80 mi | roughly 45 to 60 mi |
| Prowler | 1040Wh | up to 70 mi | roughly 40 to 55 mi |
| Cougar | 1040Wh | up to 80 mi | roughly 40 to 55 mi |
| Rebel 2 Pro | 1040Wh | up to 80 mi | roughly 40 to 55 mi |
| Cheetah 2 | 840Wh | up to 60 mi | roughly 35 to 45 mi |
| Runabout 2 | 780Wh | up to 55 mi | roughly 30 to 42 mi |
| Flux | 720Wh, or 1200Wh option | up to 55 mi | roughly 28 to 40 mi, less with a passenger |
| Rebel 2 | 720Wh | up to 60 mi | roughly 28 to 40 mi |
The realistic column is our estimate, not a promise. It exists so you can plan a commute without running out three miles from home.
The Flux deserves a note of its own: it is the only bike here designed to carry passengers, and a loaded cargo bike is the hardest case for a battery. Two children on the rear deck will pull the real figure well below the estimate above, which is exactly why it is offered with a 1200Wh pack.
How to buy for the range you need
Work out your longest regular ride, double it, and buy a bike whose realistic figure covers that. Doubling sounds excessive until the first time you forget to charge overnight.
If your commute is under 15 miles each way, almost anything in the range will do and you should choose on shape and comfort instead. If you are riding 30 miles or more in a day, or carrying a passenger regularly, go to the larger batteries: the Cheetah 2 Pro at 1440Wh or the Cougar Pro at 1200Wh.
Frequently asked questions
Does using the throttle use more battery than pedalling?
Yes, considerably. Throttle-only riding can use two to three times the energy per mile compared with pedalling in a low assist level.
Why is my real range lower than advertised?
Advertised range is measured with a light rider, on flat ground, in the lowest assist level, in mild weather, with correctly inflated tyres. Change any of those and the number falls. Change all of them and it can halve.
Does cold weather damage the battery?
Riding in the cold does not damage it, it just reduces available capacity temporarily. Charging a battery that is below freezing can damage it. Bring the battery indoors, let it reach room temperature, then charge.
Can I carry a second battery?
On some models yes. Owners of the Cheetah platform commonly fit an auxiliary pack for genuinely long days, and the Flux is sold with a second battery option. Email us before buying one so we can confirm compatibility with your exact model.
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