diff --git a/pi/backend/arduino_service.py b/pi/backend/arduino_service.py
index 1795105..feb5f35 100644
--- a/pi/backend/arduino_service.py
+++ b/pi/backend/arduino_service.py
@@ -298,9 +298,11 @@ class ArduinoService:
                     result[name] = float('nan')
 
         # IMU axis correction for mounting orientation
-        # Roll needs inverting for motorcycle frame alignment
-        if 'roll' in result and not math.isnan(result['roll']):
-            result['roll'] = -result['roll']
+        # Pitch/yaw inverted for motorcycle frame alignment (roll left as-is)
+        if 'pitch' in result and not math.isnan(result['pitch']):
+            result['pitch'] = -result['pitch']
+        if 'yaw' in result and not math.isnan(result['yaw']):
+            result['yaw'] = -result['yaw']
 
         return result
 
diff --git a/pi/backend/main.py b/pi/backend/main.py
index df11a1a..1e9a590 100644
--- a/pi/backend/main.py
+++ b/pi/backend/main.py
@@ -20,8 +20,8 @@ socketio = SocketIO(app, async_mode="gevent", cors_allowed_origins="*")
 gps = GPSService()
 arduino = ArduinoService()
 
-# Throttles for emission rate limiting (2Hz for arduino, 1Hz for GPS)
-arduino_throttle = Throttle(min_interval=0.5)  # 2Hz max
+# Throttles for emission rate limiting (20Hz for arduino, 1Hz for GPS)
+arduino_throttle = Throttle(min_interval=0.05)  # 20Hz max
 gps_throttle = Throttle(min_interval=1.0)      # 1Hz max
 
 # Track connected clients
@@ -157,7 +157,7 @@ def throttle_flusher():
     """Periodically flush pending throttled data."""
     import gevent
     while True:
-        gevent.sleep(0.5)
+        gevent.sleep(0.05)  # 20Hz flush rate
 
         if arduino_throttle.has_pending:
             arduino_throttle.flush(lambda d: socketio.emit("arduino", d))