Written by Muneeb Rana · Last updated 26 October 2026
Quick answer: An e-bike speedometer on your phone shows GPS speed and trip data, which helps you understand when your motor assistance cuts out, such as 20 mph for US Class 1 and 2, 28 mph for Class 3, or 25 km/h for EU pedelecs. It is an estimate, not a certified meter. Mount it securely and set it up first.
TL;DR
- Know your class cutoff.
- GPS speed estimate.
- Secure mount.
- Path limits may be lower.
- Not a certified meter.
E-bike speedometer setup
- Open Speedometer PRO before you move and allow precise location.
- Pick MPH or KM/H and the analog or digital meter.
- Tap Start on the Current Trip card if you want distance and averages.
- Mount the phone securely.
- Leave it alone until you stop.
Assist limits
| Rule | Cutoff |
|---|---|
| US Class 1/2 | 20 mph |
| US Class 3 | 28 mph |
| EU EPAC | 25 km/h |
Details: e-bike speed limit.
Why speed matters
Heavier, faster bikes need more stopping distance; see the stopping distance calculator for the physics.
Battery
Your phone and e-bike batteries are separate; carry a power bank or USB from the bike if supported.
Comparing the bike's display with GPS
Many e-bikes have their own display, which calculates speed from a wheel magnet and the wheel size set in its menu. If the wheel size is wrong, the display will be off by the same percentage. Riding a steady straight stretch and comparing it with GPS speed is a quick sanity check; a consistent gap suggests the wheel size setting needs correcting.
Paths and shared spaces
Even where an e-bike may legally reach 20 or 28 mph with assistance, paths and shared-use trails often carry lower limits or rules about e-bike classes. A speed readout helps you keep to them, especially downhill where speed builds without effort.
Weight and braking
E-bikes are heavier than most pedal bikes, and the extra mass, plus higher average speeds, means longer stopping distances. Leave more room, and check brakes and tyres more often.
Hills and descents
On descents, e-bikes can quickly exceed assistance speeds without motor help. Watch your readout and brake early.
Checking assistance cut-off
A speedometer makes it easy to see where your motor stops helping. On a flat road, pedal steadily up to the point where assistance fades and note the reading: on many EU and UK pedelecs it's around 15.5 mph (25 km/h), and on US Class 1 and 2 bikes 20 mph. If it fades well below that, check your assistance level and battery charge.
Safety
Helmets, lights, and respectful speeds on shared paths.
Related: Speedometer use cases · E-bike speed limit and classes · Bike speedometer app: GPS speed for cycling · Average cycling speed · Best bike speedometer apps · GPS speedometer: live speed from your phone's satellites · Average walking speed
Get Speedometer PRO on Google Play · Download on the App Store · Set it up before you move; never handle your phone while driving.
Sources
- Electric bikes and the three-class system (PeopleForBikes): peopleforbikes.org (accessed 26 October 2026)
- Electric bicycle laws (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
- Bicycle Safety (NHTSA): nhtsa.gov (accessed 26 October 2026)
- Braking distance (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
FAQ
Does my e-bike need a speedometer?
Some rules require one on Class 3 e-bikes. Check local law.
Is a phone app accurate enough?
It gives a useful estimate in open sky but is not certified.
Why does assist stop at 20 mph?
Class 1 and 2 rules cap motor assistance at 20 mph in the US.
Can the app limit my speed?
No. It only displays speed.
Does it show battery range?
No, it does not connect to the e-bike.