Want mm as integer for sorting purposes.

db/migrate/20130902201853_add_model_to_bike.rb

@@ -3,8 +3,7 @@ class AddModelToBike < ActiveRecord::Migration
     add_column :bikes, :model, :string
     change_column :bikes, :bike_model_id, :integer, :null => true
     Bike.all.each do |bike|
-      bike.model = BikeModel.find_by_id(bike.bike_model_id).model
+      bike.update_attribute(:model, BikeModel.find_by_id(bike['bike_model_id']).model )
-      bike.save
     end
   end
 end

db/migrate/20131019150459_create_bike_wheel_sizes.rb

@@ -1,8 +1,8 @@
 class CreateBikeWheelSizes < ActiveRecord::Migration
   def up
     create_table(:bike_wheel_sizes) do |t|
-      t.string :twmm
+      t.integer :twmm
-      t.string :rdmm
+      t.integer :rdmm
       t.string :twin
       t.string :rdin
       t.string :twfr

db/migrate/20131019170248_alter_bike_wheel_to_id.rb

@@ -11,8 +11,7 @@ class AlterBikeWheelToId < ActiveRecord::Migration
       else
         wheel_size_id = wheel_size.id
       end
-      bike.bike_wheel_size_id = wheel_size_id
+      bike.update_attribute(:bike_wheel_size_id, wheel_size_id)
-      bike.save
     end
 
     remove_column :bikes, :wheel_size
@@ -24,8 +23,7 @@ class AlterBikeWheelToId < ActiveRecord::Migration
 
     Bike.find_each do |bike|
       wheel_size = BikeWheelSize.find_by_id(bike['bike_wheel_size_id'])
-      bike.wheel_size = wheel_size.rdin.to_i
+      bike.update_attribute(:wheel_size, wheel_size["rdin"].to_i)
-      bike.save
     end
 
     remove_column :bikes, :bike_wheel_size_id