How to judge grade of carbon frame? Last weekend, a friend told me about a local bicycle shop(Metro Cycles) selling a Carbon Cycle of Hamilton brand. This brand is sort of known in India but only for cheap bicycles. Later I figured out that Hamilton Bicycles is an in-house brand of Metro Cycles.

So, I went to have a look at the bicycle out of curiosity. It sure is a carbon frame, but I couldn't get more information about it as the dealer as well as the website are sparse on details. I have been wondering how come they came up with one-off carbon model and who designed it and where.

Some pictures of the bicycle:





This is the product page on their website: http://hamiltoncycles.in/Product.aspx?pId=10270

My notes on the first look at the bike:


Carbon Quality Unknown. 
Endurance Geometry. 
Shimano groupset: nondescript, 8 speed.
Saddle torn.
Handlebar bad. The grip is torn. 
Brakes seem to be really bad. The rear brake has horrible stopping power. 
JHT wheels?
Size not specified
Carbon chipped. 
Horribly maintained


And they quoted ₹95000/-(~$1350) for this stupid thing. Surely, I can get a Carbon bike with Tiagra groupset for a little more.

Surely never buying this bike nor even recommending it to anybody but it has me wondering how to judge the frame quality. I have always relied on online reviews for known brands but when it comes to brands like these, I have no idea where to start. I faced a similar lack of information when I was looking for Java bikes, and thus let it go.
There are manufacturers in Taiwan and China that make bicycles for the major brands known around the world, including ons with carbon frames. It's not inconceivable that a brand known for cheap bikes could contract with one of them to make a carbon bike.

The only measurement you could easily make to judge this frame is weighing it. The highest quality CFC frames use a very careful and precise layup procedure which allows minimization of the amount of material used to get the required strength. The workers who carry this out have to be more highly skilled and take more time. Obviously this increases the cost considerably. Lower quality frames use more material as a margin of error against layup imprecision in a faster and cheaper process. 

You or an experienced rider could ride the thing and get an idea of how it feels in terms of stiffness, compliance, acceleration etc., but it's subjective and influenced by the drivetrain and wheels