Emergency recording is the feature that stops your dash cam from erasing the one clip you needed. A motorcycle camera records in a continuous loop and overwrites its oldest files forever; when a G-sensor detects the sharp deceleration of a crash or a panic stop, the system flags the current segment as protected so the loop skips over it. Everything else eventually gets recycled. That one file doesn't.
Understanding why it works that way — and what it still can't do for you — takes about five minutes and saves people a lot of grief.
Start with the thing nobody expects, loop recording deletes your footage
Dash cams don't record one enormous file. They chop video into short segments, typically one to three minutes each, and write them to the SD card in sequence. When the card fills up, the camera doesn't stop or warn you — it goes back to the oldest segment and writes over it. Then the next oldest. Forever.
That's the right design — a camera that stopped when the card filled would be useless after your first long ride. But it means your footage has a shelf life measured in hours. A dual channel 1080P setup writes roughly 6 to 10 GB per hour, so a 64 GB card holds six to ten hours before it starts eating itself. A commuter riding 45 minutes each way has about a week of history. A weekend tourer can burn the whole card in a day.
Which sets up the actual problem. After a crash you are hurt, adrenalized, and dealing with police and a driver telling a different story. Nobody in that state is thinking about file management. If the system doesn't protect the clip on its own, the loop quietly consumes it while you're at the hospital.
How the G-sensor decides something happened
Inside the recorder is an accelerometer — the same class of chip that knows which way up your phone is. It measures acceleration on three axes continuously: fore and aft, side to side, and vertical.
Normal riding produces a constant stream of small readings — throttle, braking, cornering load, potholes, expansion joints. All of it sits below a threshold and gets ignored. A collision is different in kind, not just degree: a very large spike over a very short window, often on more than one axis at once. Hard braking reads as a big fore-aft figure. A side impact spikes laterally. A lowside puts a violent vertical and lateral event through the chassis as the bike hits the pavement.
Cross the threshold and the recorder does one thing: it marks the segment currently being written as locked, plus usually the segment before it, and moves that file into a protected folder the loop is not allowed to touch. On a dual channel system, both the front and rear clips get locked together — which matters, because in a rear-end collision the front camera's view of what you were doing is often the more valuable of the two.
Thresholds cut both ways. Too sensitive and the sensor locks a clip over every speed bump until the protected folder is full of nothing. Too insensitive and it sleeps through a real crash. Most systems let you adjust this, and bikes need different tuning than cars because a frame passes far more road shock into the recorder.
Be clear about what the G-sensor cannot catch. A slow-speed tip-over may not generate enough force. Someone backing into your parked bike almost certainly won't, if the system is powered down with the ignition. And a near miss where nobody touches you produces no spike at all — which is exactly the event riders most want to keep.
The manual lock button, and when you'll want it
That last gap is what the manual lock is for. One press protects the segment you're in right now, no impact required.
The situations that call for it:
- The near miss. A car crosses your lane, you brake and swerve, no contact. Nothing triggers automatically. If you want that clip, you press the button.
- Someone else's incident. You witness a crash ahead of you. Your camera saw it, your G-sensor didn't feel a thing, and the loop is already counting down.
- Aggressive driving you may need to report. A driver deliberately brake-checking you, or a tailgater who's been on your plate for two miles.
- Right after a crash, as a backup. The automatic lock probably fired, but pressing costs nothing and covers the case where it didn't.
The catch is entirely practical: the button has to be reachable with gloves on, without taking your eyes off the road for more than a glance. A recorder buried under the seat has a manual lock feature you will never use. On systems where recording runs through the main display, like our S6 riding system, the control sits on the screen you're already looking at, which is the difference between a feature and a spec sheet entry.
What happens to each type of clip
| Normal loop segment | Locked segment | |
|---|---|---|
| Created by | Continuous recording, every segment | G-sensor trigger or manual button press |
| Stored in | Main loop folder | Separate protected folder |
| Overwritten by the loop | Yes, oldest first, automatically | No |
| Typical lifespan | Hours to days, depending on card size | Until you delete it or the protected folder hits its own limit |
| What ends it | The card coming back around | Manual deletion, formatting the card, or the protected area filling and rolling over |
| What you should do | Nothing | Export it to a phone or computer the same day |
That last row is the one people skip, so state it flatly: locked does not mean safe. Protected clips sit on the same SD card as everything else, and cards fail, corrupt, get formatted by accident, or get lost with the bike. The protected area is also a fixed slice of that card — once it's full, either new emergency clips stop saving or the oldest ones roll over.
The post-crash routine
Assuming you're physically okay, here's the sequence that keeps footage usable.
At the scene: press the manual lock if you can. Don't start pulling the card apart on the roadside — a locked clip will survive the ride home.
Same day, without exception: copy the locked files onto a laptop or phone, then copy them somewhere second. Two copies in two places. Five minutes, and it's the highest-value thing you'll do with the footage.
Keep the originals untouched, with original filenames and timestamps, no trimming or re-encoding. Make a short version as a copy if you need one — an edited-only file invites questions about what was cut.
Check both channels, because front and rear are separate files and the one you forget is sometimes the one that mattered. Note the incident time and the filename while it's fresh.
Then clear the protected folder so the space is free for the next event, and format the card in the device every couple of months while you're at it.
FAQ
Does emergency recording work if the bike loses power in the crash?
It depends on the design. Systems with a small internal capacitor or backup cell can finish writing and closing the current file after power is cut, which is what protects against a truncated, unplayable clip. Without that, a hard power loss mid-write can corrupt the final segment — usually the most important one. Worth asking about before you buy.
My camera locks clips on every speed bump. What do I do?
Turn G-sensor sensitivity down one step, then verify it still triggers with a firm brake application somewhere safe. Factory defaults are often tuned for cars and are too sensitive for a bike.
How many locked clips can the camera hold?
Most systems reserve a fixed portion of the card for protected files rather than allowing unlimited locking, since a sensitive G-sensor could otherwise fill the card and stop normal recording. Check what yours reserves, and keep the folder cleared.
Does a locked clip include the moments before the impact?
That's the point of locking the preceding segment as well as the current one. What matters legally is usually the ten seconds before contact, not after, so a system that only protects the segment containing the impact can clip the approach short. Check how far back yours reaches.
Emergency recording is one piece of a system that has to get several other things right — sensor quality, mounting, storage endurance, and coverage front and rear. Our motorcycle dash cam buying guide walks through all of it. If you're adding cameras to a bike that already has a display, the zinc alloy camera kit handles the front and rear channels, with the lock control on the main screen.
