Was the ‘Bat Bike’ an addon or mod to the experimental Batmobile, or did it always exist?

Was the ‘Bat Bike’ an addon or mod to the experimental Batmobile, or did it always exist?

When we are first introduced to the Batmobile in Batman Begins, we are told that the Vehicle was built initially as a 'bridging' vehicle to allow ground troops or heavier armour easier access into war-torn areas. 
The bridging function didn't pan out, but the heavily armoured stealth vehicle turned out to be exactly what Batman needed. 
However, there was no mention of the 'detachable motorbike' capability in the first film. Was this retroactively added to the vehicle? (Either in canon, or by the director) Or was the design for the 'Bat bike' included in the original design for the entire vehicle?

Solutions/Answers:

Answer 1:

It is never explicitly stated that the bike was either an original part of the vehicle or an add-on. Nolan has, however, implied in several interviews and DVD special features that he intended on destroying the Batmobile and using the Batpod in Batman Begins. It is possible from that knowledge to surmise that the Batpod must have been an original design feature; he couldn’t use it in the first film if it wasn’t already part of the design.

Answer 2:

It’s so strange that you’ve asked this, I inadvertently blew my own mind when I stumbled across the answer in my own question last night!

The Batpod is actually constructed from the two front wheels of the vehicle:

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If you watch the gif carefully, you’ll see the rear wheel is on some kind of articulated axle which springs round to the back and helps to propel the pod out of the wreckage!

This is brand new to me, too!

Whereas there is probably no definitive answer, I think the fact that this system is in place and the tumbler has not drastically altered in appearance from Batman Begins to The Dark Knight Rises indicates it has been there all along…

References

The age difference between Bruce Wayne and Alfred?

The age difference between Bruce Wayne and Alfred?

In general, comics, series and movies. What's the age difference between Bruce Wayne and Alfred?

Solutions/Answers:

Answer 1:

In the comics, the answer is “complicated”.

In the early comics (the Earth-One and Earth-Two versions) Alfred was roughly the same age as Bruce Wayne: Alfred’s father had been Thomas Wayne’s butler. He only introduced himself to Bruce after his own father had died and asked Alfred to carry on his legacy as the Wayne’s butler. By the time Bruce met Alfred, he was already Batman.

In later comics (starting with the New Earth version), Alfred had been the Wayne’s butler for all of Bruce’s life, making him most like at least 30 years or so older than Bruce by the time he becomes Batman.

Generally speaking, the movie and television media tend to follow the later comics, where Alfred is already an adult — and working for the Wayne family — when Bruce is born. Alfred would be about the same age as Bruce’s father, and indeed acts as a surrogate father for the orphan.

We are never given a clear age or birthdate for Alfred, and in the movies, almost nothing is explained about his backstory. In Gotham he’s retired from the British military, so he’s probably at least in his mid 30s when the series airs (and Bruce is an adolescant).

References