Add BikeBrand and BikeModel models

app/models/bike_brand.rb

@@ -0,0 +1,10 @@
+class BikeBrand < ActiveRecord::Base
+  attr_accessible :name
+
+  has_many :bikes
+  has_many :bike_models
+
+  def models
+    self.bike_models
+  end
+end

app/models/bike_model.rb

@@ -0,0 +1,10 @@
+class BikeModel < ActiveRecord::Base
+  attr_accessible :name
+
+  has_many :bikes
+  belongs_to :bike_brand
+
+  def brand
+    self.bike_brand
+  end
+end