Road Bicycle Frames Buying Guide
The frame is the basis of both the strength and the beauty of the bicycle 
. Nothing besides its paint job is superficial, and when you're buying a new bike, you want to pay particular attention to the frame . You will want to know enough about size, symmetry, and materials to get a frame that fits you and your riding style and purpose.
Determining Your Frame Size
To determine your proper size, you will first need to get an accurate in-seam measurement . Once you have that set, you are good to go.
- Know that the frame size refers to the length of the frame's seat tube .
- Pro frames are measured along the seat tube in two ways: centre-to-top (C-T) or centre-to-centre (C-C).
- C-T measures the distance from the centre of the bottom bracket to the top of the top tube.
- C-C measures from the centre of the bottom bracket to the centre of the top tube.
- There is typically a 1-1.5cm difference between the two.
- This is where it gets mathematical.
- To size a C-T road frame, use the guideline of .67 multiplied with your in-seam length.
- To size a C-C road frame, use the formula of .65 multiplied with your in-seam length.
- As an example: if you have an 85cm in-seam, your C-T frame size would be .67 x 85cm, or 57cm.
- Unfortunately, most bikes are designed for men, and women often have a hard time finding a bike that will fit them well.
- Some manufacturers have made women-specific models. Ladies will want to keep their eyes open for these!
- With the right frame height, you will be able to have the correct saddle height as well.
- Most people ride bikes that are too small for them; always go with the bigger size!
- This allows for a full leg extension, with a slight bend in the leg at the bottom of the pedal stroke.
- You will want your back to be at a 45-50º angle for optimum comfort and performance, so be sure the bike frame fits just right.
Frame Materials
- Aluminium Alloy : Aluminium frames can be very stiff and light because the density is so low, but the tubes have to be much larger in diameter to compensate. Still, these "fat-tube" frames are the prevalent design for quality bikes today. They don't rust easily and are well-suited for bicycles of unconventional frame shapes.
- Carbon Fibre : Unlike metals, in which strength and stiffness properties are nearly the same in all directions, carbon fibre composites can be tuned to orient the strength where it's needed. With excellent fatigue strength, these frames can be easily moulded and won't rust very easily.
- Steel : Being the most popular material for bike construction, steel is stiff but heavy. Light frames of adequate stiffness and strength are made with relatively small-diameter tubes, but steel isn't the right material for light frames or large strong riders. Recent developments include "air-hardened" steels of very high strength, which are actually pretty affordable.
- Titanium : Titanium has an excellent balance of properties for frame building, and gives the best combination of durability and weight. Titanium alloys are half as stiff as steel, but also half as dense; even very light frames can be made stiff enough and strong enough for bigger riders to enjoy. Titanium is very corrosion-resistant and has great fatigue strength.
Related Guides
.
