Getting everyone their own intercom is a hassle
Dedicated intercoms are the usual choice for group rides, but outfitting every rider is a real hurdle. denntatsu connects riders' phones directly, with no server involved, using devices you already carry. It also works alongside intercoms for riders who already have them.
What you can do with denntatsu
Join a channel in seconds
Scan a QR code to connect offline. No server needed, works off-grid.
Push-to-talk, like a walkie-talkie
Hold the button to talk, release to listen — or go hands-free with voice-activated transmission over a Bluetooth headset. Built for close-range, tight-knit groups.
Voice and text, both ways to reach the group
Text chat works alongside voice — useful for coordinating meetup points and breaks.
How it works
- 1
Connect before you set off
While stopped, scan the host's QR code to join the channel.
- 2
Talk hands-free while riding
Connect the speaker and microphone of a Bluetooth headset or intercom to talk with your group without using your hands.
- 3
Operate only while stopped
Connecting and any screen or button operation should all be done while stopped.
Never operate the app by hand while riding. Talk hands-free on the move; operate only while stopped.
What to know before you use it
- Delivery is best-effort. Range depends on surrounding buildings, terrain, and device hardware, and is not guaranteed.
- Only one person can talk at a time (half-duplex) — this is not an always-on, everyone-talks-at-once connection.
- Voice conversation is designed for close-range, tight-knit groups where riders are in direct radio range of each other. A widely spread-out line is not guaranteed to stay connected.
- Text chat, like voice, only reaches devices you're directly connected to.
Frequently asked questions for riders
How far does it reach?
Range depends on surrounding buildings, terrain, and device hardware. Open, line-of-sight areas tend to reach farther, but no specific distance is guaranteed.
Is it free to use?
Yes, denntatsu is free to use. Normal-mode calls have a 30-minute session limit (removed with a day pass or monthly plan). The disaster SOS feature is entirely free and unlimited (SOS is not a substitute for official emergency calls, and delivery is not guaranteed).
Do we all need dedicated intercoms?
No — a smartphone is all you need to join. It also works alongside riders who already use intercoms. It's positioned as a no-hardware way to get started or complement existing intercoms, not a replacement for them.
Can I use it while riding?
Yes — connect the speaker and microphone of a Bluetooth headset or intercom to talk hands-free while riding. Any screen or button operation must be done while stopped. Note that local regulations may restrict earphone use while riding; we recommend single-ear or open-ear devices that let you hear your surroundings.
Does it work on mountain roads with no cell signal?
Yes. Because it connects devices directly with no server involved, nearby riders can connect directly even where there's no cellular signal. Delivery is best-effort — range depends on surrounding buildings, terrain, and device hardware.
Can we keep talking if the group gets spread out?
Voice conversation is designed for close-range, tight-knit groups where riders are in direct radio range of each other — reaching a widely spread-out line is not guaranteed. Also, only one person can talk at a time (half-duplex). Text chat likewise only reaches devices you're directly connected to.
Get Started
denntatsu is available now for Android. Download it free on Google Play to get started.
