This is not a robotics question, but this Stack Exchange is the closest I could find to mechanical engineering. Please refer me to a better place to ask this, if one exists. Hopefully someone might just know this.
I got a pull-back car for my boy at McDonalds, and it has two gears. It starts slow, then speeds up after about two seconds. It's impressive to me, especially given the inherent cheapness of toys sold by McDonalds. It feels solidly built as well.
I couldn't find anything related to this concept. The wiki on pullback motors does not include any information on multiple gears.
Any ideas on how this works?