I new to the road cycling world and was wondering what exactly makes a good frame good.

I'm not talking about the obvious stuff - cf vs. aluminum vs. steel (material differences)

Many of you experienced bikers can just see two frames and instantly compare them - what are you looking for?

Is the aerodynamics?
Welds?
Symmetry?
Weight?
Manufacturer?
Warranty?
Finish?

It's just that many people frown on certain bike frames (cheap ones, no brands, etc...) but to me they are exactly the same as more costly ones and perform the same duty (holding everything together).

I can see why which components (gears, shifters, rims, wheels...) are prefered since the better ones are lighter, more precise, have less failures (less shifting problems) and are more effecient.

The trouble I am having is just seeing what is so important about the frame (and I know that it is vital). I see two Aluminum frames with similar weight and specs but yet one is bad and the other is good - the only major difference is the price... To me a frame is just to hold everything together, it doesn't move (unlike the components) - it just sits there, so if two frames are made out of Al 6061, why are some so much better than the others?

Thanks for putting up with my newb questions,

A well designed bike with proper geometry for the type riding you plan on doing and, one that fits you are the two most important things to consider. Thats why years of enjoyment can be had from seemingly inexpensive bikes - even some from the far East. Get these two right first, then decide which of the other variables are important to you and, put a weighed or priority perspective on them. They are just icing on the cake when the first two are right.

I agree. A really good bike fits you perfectly, including both your riding style and your body dimensions. Aerodynamics mostly has to do with your riding position (low front end), but a lot of riders don't have the strength to be comfortable in that position for long periods of time. That's why more upright road bikes are becoming popular.

ill chime in relative to aluminum frames, because they seem to run the whole range of prices and quality, and i've had experience with a cross section of them.

in terms of the raw frame, quality is determined by 3 things more or less.

alloy: these can be standard 6000 or 7000 series alloys at the low-mid range, you pay more for scandium alloys that allow for lighter frames.

tubing: how it is shaped or "butted" low end-frames will have little or no butting meaning the tube has the same cross section along its whole length. this makes the bike heavier and often less stiff. heavily, or continuously butted tubes (like on caad frames) use only as much material as needed at any point to achieve the best strength/weight ratio. butted tubes are harder to produce and thus cost more.

welds: low-end welds will look lumpy and small, high quality welds will look like big, completely smooth fillets. these are the strongest and least likely to crack. low-end welds can be done by robots, but high end welds will be done by a skilled welder who knows just how much material too add (thus it costs more)

even high end manufactures like trek and giant will have frames with many of the lower end features described above, but they will come with a good warranty, and thus demand a higher price than an otherwise similar frame bought on line without a warranty or as much of a rep.

also consider that most low end aluminum frames (from all brands) are made in a handful of chinease/Taiwanese factories. so the only difference between a large sector of that market can be just geometry and brand sticker.

I'd say alot of people decide good/bad by looking at the brand name...

Thanks for all of the input, it's all been greatly appreciated!!!!