diff --git a/lib/services/cloud/cloud_models.dart b/lib/services/cloud/cloud_models.dart
new file mode 100644
index 0000000..421c7da
--- /dev/null
+++ b/lib/services/cloud/cloud_models.dart
@@ -0,0 +1,98 @@
+import 'package:flutter/foundation.dart';
+
+/// Stable cloud-facing representation of the MotorSignal rider profile.
+/// Firebase UID is the identity; username is a future public handle and is
+/// intentionally not used as an account identifier.
+@immutable
+class CloudUserProfile {
+  final String id;
+  final String? username;
+  final String? displayName;
+  final String? profilePhotoUrl;
+  final String? bio;
+  final String? location;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+  final Map<String, dynamic> privacySettings;
+  final Map<String, dynamic> preferences;
+
+  const CloudUserProfile({
+    required this.id,
+    this.username,
+    this.displayName,
+    this.profilePhotoUrl,
+    this.bio,
+    this.location,
+    required this.createdAt,
+    required this.updatedAt,
+    this.privacySettings = const <String, dynamic>{},
+    this.preferences = const <String, dynamic>{},
+  });
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'username': username,
+        'displayName': displayName,
+        'profilePhotoUrl': profilePhotoUrl,
+        'bio': bio,
+        'location': location,
+        'createdAt': createdAt.toUtc().toIso8601String(),
+        'updatedAt': updatedAt.toUtc().toIso8601String(),
+        'privacySettings': privacySettings,
+        'preferences': preferences,
+      };
+}
+
+/// Cloud DTO for a motorcycle. Local Drift IDs remain stable within the
+/// installation; the string form is used as the Firestore document ID.
+@immutable
+class CloudMotorcycle {
+  final String id;
+  final String ownerId;
+  final int year;
+  final String makeId;
+  final String makeName;
+  final String modelId;
+  final String modelName;
+  final String? variantId;
+  final String? variantName;
+  final String? nickname;
+  final bool isDefault;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+  final String? specificationJson;
+
+  const CloudMotorcycle({
+    required this.id,
+    required this.ownerId,
+    required this.year,
+    required this.makeId,
+    required this.makeName,
+    required this.modelId,
+    required this.modelName,
+    this.variantId,
+    this.variantName,
+    this.nickname,
+    required this.isDefault,
+    required this.createdAt,
+    required this.updatedAt,
+    this.specificationJson,
+  });
+
+  Map<String, dynamic> toJson() => {
+        'id': id,
+        'ownerId': ownerId,
+        'year': year,
+        'makeId': makeId,
+        'makeName': makeName,
+        'modelId': modelId,
+        'modelName': modelName,
+        'variantId': variantId,
+        'variantName': variantName,
+        'nickname': nickname,
+        'isDefault': isDefault,
+        'createdAt': createdAt.toUtc().toIso8601String(),
+        'updatedAt': updatedAt.toUtc().toIso8601String(),
+        'specificationJson': specificationJson,
+      };
+}