Bicycles are used for transportation. Adding interfaces adds functionality so the bicycle can do more for the user. Let's examine some of these:

1. kickstand interface- allowing a kickstand for commuting

2. water bottle interfaces - allows for water bottles so you can go on longer rides ( and possibly tour )

3. fender interfaces - allows protection from the elements

4. rack interface - allows users to carry stuff on the back of the bike ( and possibly tour )

5. head tube interface - allows you to carry stuff on the front of the bike

6. Front derailleur interface- allows one to add many more gears

Overall, these simple interfaces add to the functionality of a bicycle. We try to add as much as possible to our bikes.