www.danscomp.com click faq/tech and click a category.
Generic parts like pedals, cranks and chain you can get from any bike store. Proprietary parts you have to get from the manufacturer.
polyp
Poptropica has no bar to brace, but you can costumize braces and press the space bar to do certain things in certain parts of some islands, like throw ninja stars on Red Dragon Island.
yes
It has many parts that work together to preform a function. Just like other comples machinesIt's got wheels, axles, levers and gear ratios.Because it consists of many simple machines.A bicycle is built up of several simple machines, (the lever, wheel and axle etc), and several simple machines interacting becomes a compound machine.
Bicycle parts can be seen at many stores that sell bikes like Wal-Mart , best buy , and a sports store. Here are a couple of sites for you to look at www.lonelyplanet.com/thorntree/thread.jspa?threadID=2172130 , and www.qbp.com , and www.slanecycles.com .
yes... a leg brace is like a cast
the gears and where the axis of the wheels
sounds like you have a bad cv axle. If it is the axle, you are looking at about $100 for the parts.
Ryally depends on what it is that has broken. Although some parts might be special even stationary bikes tends to rely heavily on stock parts. Things like pedals, chain and sprockets are likely to be bone stock and easily replaced at the nearest bicycle store.
A true race bike is probably lighter, and may have another brake set up than a "normal" BMX. also you might have different parts that make the bike itself heavier, like if you are comparing a street or dirt bike to a race bike the back rim on the street/dirt bike the axle is going to 14mm instead of 3/8 axle, but other than that theres really nothing but gearing
he wore invisalign (a clear retainer like brace), i think when he was 16-17 :)