Originally Posted by Mild Al
I'm hoping some of you bike mechanics can explain this to me, at least in general terms. Everyone seems to "know" that some compnnents are better than others, but no one ever says what, exactly, makes them better. What makes the Shimano Deore better than the Shimano Alivio? What, besides the name on the box, makes a SRAM 7.0 better than a SRAM 5.0?
One guy (who may not know what he's talking about ) told me that the lesser models have plastic bearings, while the more expensive models have metal bearings. Is he right?
I realize that there might be MANY differences from one brand/model to another--but is there a general pattern? Before I spend an extra $100 or whatever for a higher level of component, I'd like to know why I'm spending the money. (I don't want to be one of those guys who brags about his components without having any idea what he's talking about.)
I think that there are two answers to your question: One has to do with the actual physical differences in the components and the other has to do with the relative performance of the components.
The performance differences are easier to explain. The higher cost components do everything a little bit more crisply. Shimano, for example, offers 5 different levels of road bike components. I can feel a subjective difference if I move up or down 2 component groups but I don't notice much if I only move one component group.
The subtle performance differences are due to the materials the products are made of and to the manufacturing processes that were used.
Manufacturers generally use metal in areas where rigidity is important. Those parts are usually shaped by forgeing. The more expensive parts use stronger, more expensive alloys that are heated less before being shaped in the forging hammer. Stronger, in this case, means that they actually use less metal so the part is lighter in weight.
The area that drives the bike mechanics crazy has to do with secondary machining and fasteners. Parts that have sloppy fit and poor fasteners suck! When you go to adjust them they tend to not want to move at all - then jump past the sweet spot. They're harder to adjust and tend not to stay adjusted as well.
As another poster mentioned, the good stuff stays good looking longer too.
As little extra as you have to pay for Shimano V-brakes, for example, I can't understand why anybody would want a bike with Pro-Max linear pull brakes.