Stiff vs Flexing bike frames
Posted: 25 Nov 2014, 09:25
Came across this guy Jan Heine, a US-based bicycle journalist.
He claims that stiff bikes are not necessarily good. Says that an appropriate flex in a frame is often desirable. Heine refers to this as 'planing'. A term taken from boating. Have a listen to this podcast interview.
http://community.terrybicycles.com/medi ... laning.mp3
Heine claims (it is) "clear that many riders perform better on flexible frames, apparently because it allows them to apply their power more efficiently. Many riders and builders extol the virtues of a “lively” frame made from flexible tubing. When we tested different frame tubing in a double-blind test (Bicycle Quarterly Vol. 6, No. 4), we found that two of three riders preferred the most flexible frame both for constant efforts and for all-out sprints. (The third rider could not tell the – very small – differences between the frames in our test.)
Of course, the real story is more complex. There is more to bicycle performance than overall frame stiffness. Frames can be too flexible for a given rider and application. Some riders may even prefer very stiff frames. However, it is clear that the old mantra of stiffer = more performance is not true for most riders." (END QUOTE)
Heine's assumption is that for 'normal' riders, stiffness isn't necessary in a bicycle. A rider with limited power output is not optimised by a stiff frame. A flexible frame wouldn't work for a strong rider, but will work with a weaker one. Flexible frame 'returns' power back to the drivetrain. It is just a matter of choosing a frame with the right amount of flex for your power output.
http://janheine.wordpress.com/2011/10/0 ... stiffness/
He claims that stiff bikes are not necessarily good. Says that an appropriate flex in a frame is often desirable. Heine refers to this as 'planing'. A term taken from boating. Have a listen to this podcast interview.
http://community.terrybicycles.com/medi ... laning.mp3
Heine claims (it is) "clear that many riders perform better on flexible frames, apparently because it allows them to apply their power more efficiently. Many riders and builders extol the virtues of a “lively” frame made from flexible tubing. When we tested different frame tubing in a double-blind test (Bicycle Quarterly Vol. 6, No. 4), we found that two of three riders preferred the most flexible frame both for constant efforts and for all-out sprints. (The third rider could not tell the – very small – differences between the frames in our test.)
Of course, the real story is more complex. There is more to bicycle performance than overall frame stiffness. Frames can be too flexible for a given rider and application. Some riders may even prefer very stiff frames. However, it is clear that the old mantra of stiffer = more performance is not true for most riders." (END QUOTE)
Heine's assumption is that for 'normal' riders, stiffness isn't necessary in a bicycle. A rider with limited power output is not optimised by a stiff frame. A flexible frame wouldn't work for a strong rider, but will work with a weaker one. Flexible frame 'returns' power back to the drivetrain. It is just a matter of choosing a frame with the right amount of flex for your power output.
http://janheine.wordpress.com/2011/10/0 ... stiffness/