Framing Materials

The cost of a mountain bike frame is proportionate to

its material, as well as the treatment that material

has received. Currently, there are five types of

material used in mountain bikes - high tensile steel,

chromoly steel, aluminum, titanium, and carbon

fiber. Oversized diameters, heat treating, and butting are

tubing material treatments that will increase the

cost of a frame as well.

High tensile steel

This is a very durable alloy that's found in lower

priced mountain bikes. It offers a high carbon content

which makes it less stiff than chromoly steel, so

more materials are needed to make it stiff enough for

bicycle frames, which will in turn make it that much

heavier.

Relatively inexpensive to produce, you'll find this

material in trail bikes, city bikes, and even entry

level mountain bikes. There are some bikes that come

with a chromoly seat tube, while the rest is high

tensile steel.

Chromoly steel

Short for steel alloy, chromoly is best described by

its major additives - chromium and molybdenum. This

is probably the most refined framing material, giving

over 100 years of dependable service.

Depending on the type of heat treating and butting,

you can find this material in bikes as low as 400

dollars all the way up to 1,500 and beyond. The

chromoly steel material offers very good durability

and a compliant ride characteristic.

Aluminum

For the past 15 years, aluminum has been refined in

pretty much the same way as chromoly. There have

been various alloys developed, as well as heat

treatment, oversizing, and butting. With dual

suspension bikes, aluminum is the preferred material

as it's the stiffest and most cost effective.

Aluminum is stiffer than chromoly, and therefore it

will crack before chromoly. Of course, this depends

on how you ride and how much abuse you give the frame.

The advantages of aluminum is that the frame is very

light and very stiff through oversizing or butting.

Titanium

Even thought it's somewhat exotic, the prices for

this material have come down over the last few years.

Frames made of titanium remain expensive because it

takes longer to weld the tubes to the frame.

Titanium is considered an alloy, normally mixed with

small amounts of vanadium and aluminum to give it

better weldability and ride characteristics. More

compliant than chromoly, it offers better fatigue

and corrosion properties.

The material you choose for your bike, all depends

on where you ride and what style you use. Almost

all materials will last you for years, as long as

you take care of your bike and treat the frame with

some respect.