diff --git a/lib/services/cloud/firebase_account_sync_service.dart b/lib/services/cloud/firebase_account_sync_service.dart
new file mode 100644
index 0000000..5279967
--- /dev/null
+++ b/lib/services/cloud/firebase_account_sync_service.dart
@@ -0,0 +1,72 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:firebase_core/firebase_core.dart';
+import '../../database/database.dart';
+import '../auth/auth_service.dart';
+import 'cloud_models.dart';
+
+/// Synchronizes account/profile and motorcycle metadata independently of the
+/// ride upload pipeline. This keeps identity data small and queryable while
+/// leaving high-frequency telemetry in the existing ride/R2 path.
+class FirebaseAccountSyncService {
+  final AppDatabase _db;
+  final AuthService _auth;
+  final FirebaseFirestore? _firestore;
+
+  FirebaseAccountSyncService({
+    required AppDatabase db,
+    required AuthService auth,
+    FirebaseFirestore? firestore,
+  })  : _db = db,
+        _auth = auth,
+        _firestore = firestore ?? _resolveFirestore();
+
+  static FirebaseFirestore? _resolveFirestore() {
+    try {
+      if (Firebase.apps.isNotEmpty) return FirebaseFirestore.instance;
+    } catch (_) {}
+    return null;
+  }
+
+  bool get isAvailable => _firestore != null && Firebase.apps.isNotEmpty;
+
+  Future<void> syncAccount({DateTime? now}) async {
+    final user = _auth.currentUser;
+    if (user == null || user.isAnonymous || !isAvailable) return;
+
+    final timestamp = (now ?? DateTime.now()).toUtc();
+    final profile = CloudUserProfile(
+      id: user.uid,
+      displayName: user.displayName,
+      profilePhotoUrl: user.photoUrl,
+      createdAt: user.createdAt?.toUtc() ?? timestamp,
+      updatedAt: timestamp,
+    );
+
+    final userRef = _firestore!.collection('users').doc(user.uid);
+    await userRef.set(profile.toJson(), SetOptions(merge: true));
+
+    final motorcycles = await _db.select(_db.garageMotorcycles).get();
+    for (final motorcycle in motorcycles) {
+      final cloud = CloudMotorcycle(
+        id: motorcycle.id.toString(),
+        ownerId: user.uid,
+        year: motorcycle.year,
+        makeId: motorcycle.makeId,
+        makeName: motorcycle.makeName,
+        modelId: motorcycle.modelId,
+        modelName: motorcycle.modelName,
+        variantId: motorcycle.variantId,
+        variantName: motorcycle.variantName,
+        nickname: motorcycle.nickname,
+        isDefault: motorcycle.isDefault,
+        createdAt: motorcycle.dateAdded.toUtc(),
+        updatedAt: motorcycle.lastUpdated.toUtc(),
+        specificationJson: motorcycle.specificationJson,
+      );
+      await userRef.collection('motorcycles').doc(cloud.id).set(
+            cloud.toJson(),
+            SetOptions(merge: true),
+          );
+    }
+  }
+}