Posted 01.13.2016 in Articles
The backbone of every bike is its frame. Understanding the characteristics of the materials used in frame construction can help you decide which material will suite your riding habits and budget best. There are five common materials used in bicycle frame construction. Essentially, though, what you pay for is inversely proportional to the weight of your bike. The less it weighs, the more more you’ll pay.
Steel is inexpensive and strong. It flexes enough to offer a degree of shock absorption. Some riders refer to it as feeling lively. It is easy and inexpensive to repair if needed; just weld the damaged part. Steel used to be the heavy option, but advances in design and the use of alloys have made relatively lightweight steel frames available. Not surprisingly, the lighter steel frames are more expensive. Steel frames can also suffer from rust, so care must be taken to ensure the frame doesn’t succumb to the elements.
Aluminum alloys are stiffer and lighter than steel and have become the top choice for many ebike manufacturers. The stiffness allows a better transfer of power, but that stiffness does translate to a harsher ride. Because of the stiffness the metal fatigues and can ultimately wear out.
Titanium combines the best of both steel and aluminum. It flexes like steel giving bikes a supple feel, yet is as lightweight as aluminum. Titanium frames are expensive though. They require precise welding techniques during manufacture. These same welding requirements make repairs difficult and costly.
Magnesium is very light, about 45% lighter than aluminum. It has excellent fatigue resistance, and does not easily dent or buckle. It also provides very good ride quality in a bike because it has good damping quality. Magnesium frames are not common because the material is not easy to extrude or weld. A cast magnesium frame bike is available from Gocycle. Magnesium tube frames are made by Segal and Paketa.
Carbon fiber is made up of a sheet of parallel, continuous fibers woven together and bound with glue. These sheets are then glued together to make plies. Several plies form a laminate. These laminates can be made into any shape. Frames are constructed by gluing together the laminates, which allows designers the freedom to create any shape desired. Carbon fiber frames can be very light, but some cyclists view them as fragile. If a carbon fiber bike is wrecked the carbon layers splinter and it is sometimes impossible to repair. The cost of carbon fiber frames has come down a bit with the influx of imported frames but remain one of the higher cost materials.Carbon fiber is the only non-metal in common use in bike frames.
This article originally appeared in the Electric Car Insider Electric Bike Buyer's Guide in the Q3 2015 issue. Electric Car Insider magazine is available at thousands of independent newsstands across US and Canada including Barnes & Noble. Never miss an issue by subscribing.