It’s not about fitness. It’s about descents.

How Does it Work?

You attach a sensor to your bike frame and record your run. We look at when your bike actually moves.


Faster is Funner.

Maybe you race, maybe you don’t. Either way you session trails, repeat sections, and try different lines.

Social, no.

Putting in the work and beating your own time is worth more than some silly KOM.

Private, yes.

You're not a big fan of the heatmaps. Let's keep hidden spots hidden.


Precise to a quarter of a second. Every time. On every downhill and descending trail.


321 Timer does not require extra equipment on the trail. You just need a sensor that attaches to your bike and the app for your iPhone. We're happy to tell you when the Android version will be available .

Training for Speed.

321 Timer is for those who are serious about timing your runs to gain speed and insight.


Who is this for?

321 Timer is an acurate timer for Enduro and DH training. It's for all of us who want to go faster downhill on our trail bikes or DH bikes. It's for those of of us who practice lines and push back up to to nail a section.

What do I need?

  1. A sensor tag
  2. A sensor tag holder
  3. An iPhone with our app:

Where do I get a sensor tag and holder?

See the purchase page

How does it work?

You attach a sensor to your bike frame and record your run. We observe when your bike actually moves. Unlike other services that are based on GPS we are precise. GPS is typically 1-2 seconds behind.

How do I use it?

Atttach the sensor to your bike and download the app. Pair the sensor and the app. Start the timer, do your run, stop the timer, pedal back up and start the timer again, and repeat.

How do I attach the sensor to my bike?

Is it like Strava?

Strava is great for tracking how much you ride and great for road cycling and for long mountainbike rides with breaks. 321 Timer is great for timing descending runs. And specifically good when you do many laps of the same run.

321 Timer Garmin/Strava Freelap
Precise Yes, to a quarter of a second Can be off by 10 seconds Yes, to a 100th of a second
Requires equipment setup at the end No No Yes
Good for hours long rides with pauses. No Yes No
Good for speed / race training Yes No Yes

Can I attach the sensor another part of the frame?

Please attach the sensor on your frame where the top tube and down tube meet. That way we can better compare bike movement across bikes.

What does it cost?

See the purchase page

iOS and Android?

Get the iOS ap from the App Store

We are still working on an Android app.

Can it be used for timing a race?

We don't think we are precise enough for race timing. Races are frequently determined on 100th of a second. Use a beacon system like

Does it work for XC trails?

Not yet. There isn't enough vibration / bike movement to acurately detect start and stop. We are working on this.

Does it work for climbs?

We haven't tested it yet.

How do I get support?

Contact us at