You don't need to leave the class. You can reconnect from the in-class menu.
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 — HR should resume within a few seconds.
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 ~12 months.
Out of range — BLE is ~10 m clear; if your phone is far from the bike, signal can drop.
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:
HR signal missing → power metrics are duplicated (so the dial doesn't go blank).
Bike signal missing → HR metrics are duplicated.
Both missing → inactive state.