Bike frames have mostly been made of steel. While having a number of advantages, steel also has some disadvantages. Weight being the most disadvantageous, strength would be the greatest advantage. If you are prepared to pay for it, you can get a lighter and better bike. So here is an overview of bike frame materials currently being used in bike and recumbent cosntruction.
Recumbent bike frames are not as standardized as frames of upright bicycles. Since recumbent bikes are not allowed in traditional bike racing, such as the Tour de France, it would seem the same interest in building lightweight recumbent bikes doesn’t have the same appeal or demand. It may seem that way, but you can find recumbent bikes made of titanium tubing, aluminum, lightweight steel tubing known as Cromolly, even carbon fiber.
Traditionally and for decades, upright bicycles, tricycles, most modes of two or three wheeled personal transportation were made of steel. It was cheap, readily available, and durable against most elements other than rust. Time produced stainless steel, iodized steel and other qualities more resistant to rust that were far too expensive for mass production.
If you want a light-weight bike, titanium may be one the best materials. It weighs nearly half that of Cromolly steel, is very durable and does not rust. The only drawback is the price, as titanium is expensive. However when compared to the potential lifespan of a recumbent made from titanium to that of any steel product, the high cost becomes less significant.
Even though building a recumbent frame with titanium may be expensive, producing titanium frames requires much more skill than a steel frame. It’s weatherproof, does not require any paint, and is very comfortable to ride as the material absorbs much of the road vibration.
Aluminum is not as suitable for recumbent bikes. The tubes are stiff depending of the wall thickness and diameter, which can make the ride jarring. Aluminum frames also have the shortest fatigue life of popular frame materials, which can be as short as five years. That aluminum does not rust doesn’t compensate for the short lifespan.
Recumbent trikes are being manufactured in larger numbers with aluminum frames, with a sprinkling of carbon fiber and titanium. Homebuilders and the eternal hobbyist continue pushing the limits of what these materials can do, in the search for lightweight recumbent frames and bicycle tubing materials.
Recumbent trikes may be the exception to aluminum construction. Trike frames made with the typical cromolly steel tubing tend to be heavy, many upwards of 50 lbs. which is not necessarily easy to pedal, even on flat surfaces. The result has been some serious efforts with aluminum, perhaps one of the better examples being the Catrike, made near Orlando, Florida.
Brazilian Mechanical Engineer, Paulo Camasmie, developed his ideal design in 2000. Learn more about Paulo, his dream, and what has occurred in those 16 years of life for his Catrike, and how it has shown the capabilities of aluminum frames for recumbent trikes.
Lately, carbon fiber has become popular in bike frames. There are more recumbent bikes made of carbon fiber appearing in the marketplace, even though the process has yet to reach it’s maturity. The early carbon fiber frames had a number of shortcomings, mainly where steel components such as cranksets, head tubes or fork ends were introduced into the frame. Over time corrosion could create a weakness in the strength, but things have changed.
While cyclists may love carbon fiber tubing, as it provides a comfortable ride and makes the bike very responsive, it also has the longest fatigue life of any frame material next to titanium and does not rust. The only problem with carbon fiber, like titanium, it is very expensive. A great example is the Lightning R-84 by Lightning Cycle Dynamics.
Clearly one of the most expensive recumbents in the market. Expensive yes, but you’ll struggle a great deal attempting to find a better recumbent made with more attention to detail. A frame exposing a marriage of titanium and carbon fiber are just part of what make this model unique. Lightning Cycle Dynamics, founder and Mechanical Engineer, Tim Brummer, with nearly 30 years of experience along with 20 World Records, give testimony to what goes into such a bike as the R-84.