If your heart rate strap stops reading during a class, you don't need to leave — you can reconnect it from the in-class menu on your Rider Dials.
Reconnect without leaving the class
On your Rider Dials, tap the menu icon (top right).
Tap Bluetooth connections.
Tap your heart rate monitor to reconnect it.
Return to the Rider Dials — your heart rate should resume.
Common causes
Dry contacts on the strap — moisten the contact pads.
Loose fit — tighten the strap so it doesn't slip.
Battery low — most HR straps use a CR2032 that lasts around 12 months.
Out of range — BLE (Bluetooth Low Energy) has a short range, so keep your phone on the bike's phone tray rather than off the bike.
Another phone paired to the same strap — only one device can connect at a time.
What you'll see if HR drops mid-class
CicloZone has fallback logic, so the dial doesn't just go blank:
Heart rate signal missing → your power metrics are duplicated onto that dial.
Bike signal missing → your heart rate metrics are duplicated instead.
Both missing → the dials show an inactive state until one of them reconnects.
Still not reading?
Carry on and finish the class — your power data still records perfectly well without a heart rate strap, and it's not worth stopping mid-session. Afterwards, ask in the chat and include:
Your heart rate strap's make and model.
Your phone model and OS version.
Whether the strap works with any other app on your phone.
Whether you've tried a fresh battery.
If the strap doesn't work in any app, it's usually the battery or the strap itself rather than CicloZone. Check "Which heart rate monitors are compatible?" too — CicloZone connects over Bluetooth only, so an ANT+-only strap will never appear.