Cervelo Renaissance
Cervélo's extensive computer modeling and design work combined with Columbus' new extreme strength Thermacrom steel and industry leading tube manufacturing capabilities, give the Renaissance a spectacular ride with the stiffness of frames weighing over a pound more. Each frame component and fitting was chosen for improved function and ultimate light weight. At under 3 lb. (for a 54cm), the Renaissance is the world's lightest and highest stiffness-to-weight steel frame.
When we started designing the Renaissance our goals were simple: it had to be light, stiff, comfortable and steel. It took us about a year to design a tubeset that met these criteria, but unfortunately there was no tubing manufacturer that could make the tubes to our specifications. That all changed when Columbus developed their Thermacrom alloy, which is truly a step above the competition. Using Thermacrom (which they use for their own Foco tubeset), Columbus was able to produce the custom Smartwall tubeset for us with the wall thicknesses, buttings and shapes that we requested. These Smartwall tubesets are exclusive to Cervélo - no other bicycle manufacturer uses them. They exceed all other available steel tubesets (including Foco) in stiffness-to-weight ratio.Below, please find the technical information from Columbus regarding the Thermacrom alloy, while the specifics on the individual tubes can be found further down.
Thermacrom is a steel micro-alloyed with manganese, chrome, molybdenum and vanadium. These elements produce a marked increase in temperability, a reduction in sensitivity to overheating which ensures that a fine-grain metal structure will be obtained after welding, more able to withstand fatigue stresses, better characteristics of strength and tenacity and better characteristics of resistance to corrosion and wear. After mechanical deformation working and drawing, Thermacrom undergoes a heating and cooling cycle that gives the steel its particular microstructure. The treatment, which only ends at the time of welding by the frame-maker, enhances the mechanical characteristics of the material by giving it high breaking loads permitting completely safe reductions in thickness.
To increase the stiffness of a tube, we need to increase the diameter. Decreasing the diameter decreases the stiffness. The top tube provides stiffness in two basic directions:
ThermacromSmartwall When we started designing the Renaissance our goals were simple: it had to be light, stiff, comfortable and steel. It took us about a year to design a tubeset that met these criteria, but unfortunately there was no tubing manufacturer that could make the tubes to our specifications. That all changed when Columbus developed their Thermacrom alloy, which is truly a step above the competition. Using Thermacrom (which they use for their own Foco tubeset), Columbus was able to produce the custom Smartwall tubeset for us with the wall thicknesses, buttings and shapes that we requested. These Smartwall tubesets are exclusive to Cervélo - no other bicycle manufacturer uses them. They exceed all other available steel tubesets (including Foco) in stiffness-to-weight ratio.
Below, please find the technical information from Columbus regarding the Thermacrom alloy, while the specifics on the individual tubes can be found further down.
Thermacrom is a steel micro-alloyed with manganese, chrome, molybdenum and vanadium. These elements produce a marked increase in temperability, a reduction in sensitivity to overheating which ensures that a fine-grain metal structure will be obtained after welding, more able to withstand fatigue stresses, better characteristics of strength and tenacity and better characteristics of resistance to corrosion and wear. After mechanical deformation working and drawing, Thermacrom undergoes a heating and cooling cycle that gives the steel its particular microstructure. The treatment, which only ends at the time of welding by the frame-maker, enhances the mechanical characteristics of the material by giving it high breaking loads permitting completely safe reductions in thickness. As the table shows, Thermacrom is far superior to any other steel alloy, as can be seen in the figure below:
ComfortToptube To increase the stiffness of a tube, we need to increase the diameter. Decreasing the diameter decreases the stiffness. The top tube provides stiffness in two basic directions:
Bi-ConicalDowntube For an extremely light steel bike such as the Prodigy, it is very important to use the material in an optimal way. This means using a large diameter thin wall downtube. Unfortunately it is not possible to use differential butting on a steel tube the way we do on our Aluminum aerotubing, but there is another way to increase the stiffness of the downtube: through bi-conicalization.
This means that near the bottom bracket, where we need lateral (sideways) stiffness, we have ovalized the downtube so that the biggest diameter is in the lateral direction. Near the front, the downtube is ovalized to become as wide as possible while still fitting on the headtube. The transition between the oval cross section near the bottom bracket and the one near the headtube is fluent, so that the stresses are transferred through the tube optimally. This means that the downtube isn’t just locally ovalized, but it is ovalized throughout the entire length, thereby slowly changing shape from one extremity to the other.
When we started designing the Renaissance our goals were simple: it had to be light, stiff, comfortable and steel. It took us about a year to design a tubeset that met these criteria, but unfortunately there was no tubing manufacturer that could make the tubes to our specifications. That all changed when Columbus developed their Thermacrom alloy, which is truly a step above the competition. Using Thermacrom (which they use for their own Foco tubeset), Columbus was able to produce the custom Smartwall tubeset for us with the wall thicknesses, buttings and shapes that we requested. These Smartwall tubesets are exclusive to Cervélo - no other bicycle manufacturer uses them. They exceed all other available steel tubesets (including Foco) in stiffness-to-weight ratio.Below, please find the technical information from Columbus regarding the Thermacrom alloy, while the specifics on the individual tubes can be found further down.
Thermacrom is a steel micro-alloyed with manganese, chrome, molybdenum and vanadium. These elements produce a marked increase in temperability, a reduction in sensitivity to overheating which ensures that a fine-grain metal structure will be obtained after welding, more able to withstand fatigue stresses, better characteristics of strength and tenacity and better characteristics of resistance to corrosion and wear. After mechanical deformation working and drawing, Thermacrom undergoes a heating and cooling cycle that gives the steel its particular microstructure. The treatment, which only ends at the time of welding by the frame-maker, enhances the mechanical characteristics of the material by giving it high breaking loads permitting completely safe reductions in thickness.
To increase the stiffness of a tube, we need to increase the diameter. Decreasing the diameter decreases the stiffness. The top tube provides stiffness in two basic directions:
- It provides lateral (sideways) stiffness. Think of a bicycle, and what happens to the frame when you push on the pedal and pull on the handlebar. This is an attempt to torque the frame, pushing the top tube to one side and the downtube to the other. Looking at both tubes, it can be seen that this torque attempts to move both tubes laterally, be it in the opposite directions. To counter this, both tubes need lateral stiffness. For the downtube (which is in a complicated load situation of combined torque and bending), we achieve this with differential butting or bi-conicalization. For the top tube (which is in a simpler load situation of almost pure lateral bending), we can achieve this by increasing the diameter in the lateral direction.
- The top tube provides in-plane (vertical) stiffness. Thanks to their structure, all double diamond frames have ample in-plane stiffness. We would even like to decrease this stiffness, which can be achieved by decreasing the vertical diameter.
ThermacromSmartwall When we started designing the Renaissance our goals were simple: it had to be light, stiff, comfortable and steel. It took us about a year to design a tubeset that met these criteria, but unfortunately there was no tubing manufacturer that could make the tubes to our specifications. That all changed when Columbus developed their Thermacrom alloy, which is truly a step above the competition. Using Thermacrom (which they use for their own Foco tubeset), Columbus was able to produce the custom Smartwall tubeset for us with the wall thicknesses, buttings and shapes that we requested. These Smartwall tubesets are exclusive to Cervélo - no other bicycle manufacturer uses them. They exceed all other available steel tubesets (including Foco) in stiffness-to-weight ratio.
Below, please find the technical information from Columbus regarding the Thermacrom alloy, while the specifics on the individual tubes can be found further down.
Thermacrom is a steel micro-alloyed with manganese, chrome, molybdenum and vanadium. These elements produce a marked increase in temperability, a reduction in sensitivity to overheating which ensures that a fine-grain metal structure will be obtained after welding, more able to withstand fatigue stresses, better characteristics of strength and tenacity and better characteristics of resistance to corrosion and wear. After mechanical deformation working and drawing, Thermacrom undergoes a heating and cooling cycle that gives the steel its particular microstructure. The treatment, which only ends at the time of welding by the frame-maker, enhances the mechanical characteristics of the material by giving it high breaking loads permitting completely safe reductions in thickness. As the table shows, Thermacrom is far superior to any other steel alloy, as can be seen in the figure below:
ComfortToptube To increase the stiffness of a tube, we need to increase the diameter. Decreasing the diameter decreases the stiffness. The top tube provides stiffness in two basic directions:
- It provides lateral (sideways) stiffness. Think of a bicycle, and what happens to the frame when you push on the pedal and pull on the handlebar. This is an attempt to torque the frame, pushing the top tube to one side and the downtube to the other. Looking at both tubes, it can be seen that this torque attempts to move both tubes laterally, be it in the opposite directions. To counter this, both tubes need lateral stiffness. For the downtube (which is in a complicated load situation of combined torque and bending), we achieve this with differential butting or bi-conicalization. For the top tube (which is in a simpler load situation of almost pure lateral bending), we can achieve this by increasing the diameter in the lateral direction.
- The top tube provides in-plane (vertical) stiffness. Thanks to their structure, all double diamond frames have ample in-plane stiffness. We would even like to decrease this stiffness, which can be achieved by decreasing the vertical diameter.
Bi-ConicalDowntube For an extremely light steel bike such as the Prodigy, it is very important to use the material in an optimal way. This means using a large diameter thin wall downtube. Unfortunately it is not possible to use differential butting on a steel tube the way we do on our Aluminum aerotubing, but there is another way to increase the stiffness of the downtube: through bi-conicalization.
This means that near the bottom bracket, where we need lateral (sideways) stiffness, we have ovalized the downtube so that the biggest diameter is in the lateral direction. Near the front, the downtube is ovalized to become as wide as possible while still fitting on the headtube. The transition between the oval cross section near the bottom bracket and the one near the headtube is fluent, so that the stresses are transferred through the tube optimally. This means that the downtube isn’t just locally ovalized, but it is ovalized throughout the entire length, thereby slowly changing shape from one extremity to the other.