The box says 60 miles. Your first week says 28. That gap is not a broken battery in every case. It is a rating written for a light rider, a low assist level, flat ground, and a full charge nobody uses to 0%.
This brief is how The Ride Brief reads a range claim before we put a bike on a commuter shortlist. We are not a lab. When we have not ridden a model, we say so — and we still refuse the press-release number.
The 20-second version
Range is energy divided by how hard the motor works.
- Battery size is measured in watt-hours (Wh). That number is more honest than “miles.”
- Assist level, rider weight, hills, cold, and tire pressure decide how fast those Wh disappear.
- A useful commuter figure is often about half of the biggest number on the box — sometimes less.
If a listing only says “up to 70 miles” and hides Wh, treat the miles as advertising.
Start with watt-hours, not miles
Wh is volts × amp-hours. A 36V 14Ah pack is about 504 Wh. A 48V 14Ah pack is about 672 Wh.
Two bikes with the same “40-mile range” and different Wh are not the same product. The smaller pack will fall off a cliff the first time you sit at assist 3 with a backpack.
On our shortlists we will show Wh next to the claim. If the brand will not publish Wh, that is a finding.
What the test rider usually looks like
Brands rarely publish the full protocol. When they do, it often looks like this:
- Rider well under 180 lb
- Assist 1 or “eco”
- Flat loop
- Mild weather
- Sometimes no lights, no phone charging off the pack
Your commute is the opposite: two grocery bags, a headwind, a 7% bridge, assist 3 because you are late, 40°F in January. The motor is doing more of the work. Miles drop.
Weight is not vanity. A 220 lb rider plus a rack load is a different vehicle than the 150 lb test loop.
Assist level is a range multiplier
Pedal-assist 1 can look close to the box. Assist 3 or 4 can cut that number in half. Throttle-only (Class 2) is worse: the motor is not sharing work with your legs.
If you buy a Class 2 commuter and ride the throttle from light to light, do not plan the week around the “passthrough range” on the spec sheet.
Cold, hills, and the last 20%
Lithium packs deliver less usable energy in the cold. A winter commute in Chicago or Toronto is not a July listing photo.
Hills spend Wh on the way up and do not give them all back on the way down. Regenerative braking on a commuter e-bike, when it exists, is a rounding error — not a second battery.
Most riders should not flatten the pack to 0%. The last bars are where voltage sag feels like a dying motor. Plan as if 80% of the pack is the real tank.
“Dual battery” and range extenders
A second pack can be honest extra Wh. It can also be a way to print a bigger mile number while the main pack is small.
Add the Wh. Two 360 Wh batteries are 720 Wh — not “double the 60-mile bike.” Weight goes up. Handling changes. Charging two packs is part of the commute.
How we will treat range on The Ride Brief
Until we have ridden a model, we will not invent a mile figure and put it in bold.
We will:
- Publish the claimed range and the Wh, side by side
- Note Class 1 vs Class 2, because throttle changes the story
- Flag listings that only shout miles
- Prefer owner patterns (short winter range, display errors, swollen packs) over a single lab loop
Read the class rules first if you have not: US e-bike classes. Then the commuter shortlist.
A quick way to sanity-check a listing
- Find Wh. No Wh → walk away or assume the worst pack in that price band.
- Divide claimed miles by Wh. A claim of 80 miles on 360 Wh is fantasy for a 180 lb commuter on assist 2.
- Look at tire width and bike weight. A 70 lb fat-tire will not match a 40 lb commuter at the same Wh.
- Read the charge time. A 672 Wh pack that “charges in 2 hours” on a tiny brick is another rounding error.
None of this replaces a ride. It stops you buying the brochure.
This page will get a worked example with real SKUs when the commuter shortlist goes up. The method will not change.