Today we discuss what happens to a Tyrell frame - the process of welding, heat treatment, hand polishing and cold working.
The most popular Tyrell bike models are made using aluminum as a frame material. As mentioned in the second article in this series, aluminum is a popular frame material because of it’s relative strength and light weight.
Welding aluminum alloys can present quite a challenge due to it’s high thermal conductivity and low melting point.
Whenever aluminum is welded, it requires the utmost precision to ensure a strong bond and to prevent the risk of cracks at the welds.
Welding of titanium frames are even more challenging due to highly reactive nature of titanium to oxygen or nitrogen.
All Tyrell aluminum frames are subjected to heat treatment to increase strength. A two stage heat treatment process called T6 and T4 is used. The frames are annealed – a process of heating and softening the aluminium in an oven for a predetermined period and cooled gradually it to relieve any stresses caused by welding. This heat treatment also has the added benefit of strengthening the aluminum frame.
On some Tyrell frames, the frame material are extruded by cold working to achieve the unique shape or tubing thicknesses. This process also leads to weight reduction along with an increase in the material’s strength. Case in point are the hourglass shaped rear triangle that is visually appealing and offers vibration dampening.
Tyrell take the added step to hand polish all welds on its bike frames. This is a time intensive attention to detail that not only presents a seamless look, it offers the added benefit of a smoother surface when the frames are subject to paint.
So while many of us may never really know what goes into their Tyrell bikes, it is good to know that this is a product that has been manufactured to achieve the best possible performance, paying the most stringent attention to how the material in the frame is manufactured and manipulated results in a key reason why Tyrell mini-velos are among the best bicycles in the world.