Bicycle frame, what you need to know.

What are the considerations for a bicycle frame?

Strength
Stiffness
Weight
Material
Size

Strength

For a long journey, with carrying luggage you care more for strength and endurance then for the weight.

Don't fool yourself when you hear that a carbon frame is lighter and this preferable over, say an aluminum frame. Your frame needs to carry you and your luggage. Most likely you will carry it in an airplane, on a boat, maybe in a train or bus. The frame needs to be strong.

Stiffness

Strength and stiffness are different properties that are often confused with one another. It is important to understand the difference, if you want to understand differences in frame materials.

Imagine you clamp one end of a metal bar in a vise, and you hang a weight on the free end, causing the bar to flex temporarily. When you remove the weight, the bar snaps back to its original shape. This, different materials act different when force is put on. So the flexibility is the stiffness, while what can withstand force is strength.

The frame of my Koga Miyata World Traveler, which I bought almost 10 years ago and has done over 90.000 km.

The stiffness says something about the "elastic value" of the frame. However, comfort in riding is more influenced by tire choice (wider or smaller tires, slick or semi slick tires etc), saddle choice, riding position and if your frame is your size!

Weight

When I started my first long bicycle journey, I paid serious attention to the weight of my bicycle. The idea was that if my bike was lighter, I would cycle easier. What I forgot was that I was carrying about 40-50kg luggage.

More important then the weight of your bicycle (frame) is the endurance, the strength and stiffness. I have used aluminium and I have never regretted it.

Steel, titanium, carbon or aluminium?

A steel frame is the most heavy of the four mentioned materials, it is also the most stiff. Aluminium frames are lighter but their endurance might be less.

For long distance cycling, I would recommend either a good aluminium or steel frame. The price of aluminium frames is cheaper then a comparable steel or titanium frame (which is more endurable). And carbon bicycles are not yet made (as far as I know) for touring bicycles.

There is a benefit of steel frames, that I have quite a few seen. Although no one wants it to happen, a frame can break. I cycled with Robert Johnson in Iran who had that problem. He had a steel frame which was possible to weld in a little town in Taiwan. Should this be a consideration for you? Probably not, but steel is

Bicycle frame size

Sometimes I see people cycling on a not proper sized bicycle. Either the frame is too short, or too long. This generates discomfort. When you buy your bicycle, make sure you get your size, either 19, 21, 23 or 25 inch frame. Spend time in your shop to sort out your best fitting frame size. Nothing is worse then being on the road and realize you have the wrong frame size.