Since carbon fiber’s beginnings in bicycle design, the industry has been pushing to develop lighter, more aerodynamic wheelsets. Many innovations have propelled cycling technology forward. The difference between traditional allow rims and today’s deep-section carbon rims is striking. The enormous aerodynamic gains to be made are well understood among cyclists.
A rider is roughly responsible for 80% of the aerodynamic drag, leaving his bicycle responsible for the rest. Tighter fitting clothing and adapting to a better different riding position make some of the largest differences in the pursuit of aerodynamics, but when it comes to the frame, wheels arguable make the biggest difference. Let’s take a look at what makes BWT wheels different from other aerodynamic wheels.
The Pros and Cons of Deep Section, Disc, and 3-6 Spoke Wheels
The truth is that some wheels offer better aerodynamic performance than others. Marketing aside, well-designed disc wheels regardless of the brand perform the best to reduce drag. Examples include the Elitewheels AERO ONE and AERO ONE DISC. They are then followed by deep section wheels as well as wheels featuring a 3-6 spoke carbon configuration such as the FIVE S.
The advantages of these wheels is that they offer excellent performance in certain applications such as time trials, triathlons, and even for breaking the hour record. The difference in time-saving can be impressive. Many tests have shown that a disc wheels can outperform deep section wheels by 30 seconds over a 40km time trial. Even more impressively, they can outperform a standard spoked wheel by more than 2 minutes.
Clearly, well-designed, deep section, 3-6 spoke wheels, and disc wheels have great benefits, but there is a reason we don’t recommend them in every cycling application. Two of the major reasons why are due to their weight and relatively higher susceptibility to crosswinds. In general, the more aero a wheel is, the less crosswind resistant it is. Riding a disc wheel in windy conditions could make the bicycle unstable and difficult to ride.
Another factor that makes separates them from other wheel choices is weight. While carbon fiber wheels can be made very light, the more material used in construction leads increases weight. Depending on where you ride, having a lighter wheel might be advantageous, for example on steep climbs.
BWT: The Best of Both Worlds
Designing a wheel that can be both aerodynamic and resistant to crosswinds is something that Elitewheels has taken great steps towards. Our BWT wheelsets feature a unique undulating design that not only offers great aerodynamic performance and stability in crosswinds, but also weight-savings and stiffness. It truly is an all-round wheel that works well in most situations and conditions.
It’s unique rim shape allows the wheel to all of these things. Research has shown that undulating designs that take advantage of the Tubercle Effect have the potential to offer up to a 40% reduction in drag compared to traditional shapes. Tests have also shown a 17% increase in stiffness as compared to those without an undulating design. Let’s take a look into where the inspiration into the undulating design came from.
Biomimicry: Looking For Inspiration in Nature
The pursuit of scientific advancement is an ongoing process that takes time and energy. Advancements in bicycle wheel technology is also an ongoing process that takes significant research and development, but one thing that is true is that the natural world around us is incredibly complex. Organisms have different ingenious ways of outcompeting others and surviving.
Engineers throughout history have been inspired by natural phenomena. One famous example is the Wright Brothers looking to birds for inspiration. They noticed how birds change the shape of their wings to turn and maneuver. They applied the same concepts to their aircraft to obtain roll control.
Scientists have studied another phenomenon in nature in which tubercles, or large “bumps” on the leading edge of a wing to increase lift and decrease drag. This Tubercle Effect was first analyzed by observing the fins of Humpback Whales. Despite their large size, they are able to be more maneuverable as a result allowing them to do certain aquatic maneuvers to catch prey. Many other species also take advantage of this Tubercle Effect, but what exactly is it and how does it work?
The Tubercle Effect
Let’s take a look into what is actually happening. Tubercles, or “bumps,” channel flow over an airfoil into more narrow streams thereby creating high velocities. These channels reduce parasitic drag moving over the wingtip, leading to a reduction in drag due to the wingtip vortices. On an airfoil, lift has been shown to increase and, in computational models, the effects of drag can be reduced by 40%. Aeronautical engineers have incorporated this into plane designs. The same is true in windmills.
In the case of BWT wheels, the undulations give the rider more control in windy conditions. The airflow is attached to the rim rather than becoming more turbulent by detaching. The unique shape reduces aerodynamic drag and reduced side force regardless of the wind yaw angle.
Who is BWT for?
BWT is for the rider who wants a wheel that performs well under most riding situations, whether it is climbing, training, or just out for an easy ride. They are suitable for climbs due to being lightweight. In addition, they are also an ideal choice for descending and riding on the flats due to their aero and crosswind resistant properties. It is truly an all-round wheelset. BWT come in both rim brake and disc brake versions.