in all cases the pedals turn the chain ring, which turns another cog attached in various ways to the back wheel.


not privvy to a factory visit, but I can visualize very few hands touch the mass market parts,
those are likely a collections of assembly line robots, so as to produce the millions , at low cost..


opposite end of the spectrum, alloys and processes of areospace quality , and polished, laser etched. and anodized.
bronze bushings and so forth on the pivots.. ceramic bearings..
the Companies compete with gee whiz designs , then put athletes on them , in hopes that folks do a bit of image transferral

tending the bike is the difference [rather than the EPO abd other PED'd] but that is sports marketing in general .

pay a sports hero more than a square mile of factory workers sewing and gluing shoes together.


My self My gear head 'jones' got expressed in German stuff ..
just like the design it rightin the 1st place , and dont deal in the "NewLatest" game..


the using a parts mix is basically trying to keep the price point low enough to sell ,
in consideration of escalating costs and most of the customers forced into an Austerity economy

Of course once you zero in, on what frame size/proportions suit you,
then you can get a decent frameset and then take the mix and match, Or groupset, approach..

Even take on the fashion police and get a small wheel bike like Bike Friday's Pocket Rocket
that will be every bit as fun, Plus the kind of gears the Companies make , patterned after the
stuff the PED fueled racers turn over for finish line sprints , makes sense turning a
451 rim 20" wheel with a 53:11 , a more reasonable, 96" gear.. vs like 130"