|Some thoughts on pedal design..||John-d|
Dec 17, 2001 7:53 AM
|Looking (no pun intended) at one of the topics below regarding pedals becoming unscrewed I am thinking that the design of pedals requires more thought.
Frames are stiffer, cranks are stiffer and the whole emphasis is on sraight power transmission with minimum flex. At the same time pedals have changed in that with the old toe-clip and wide platform design the load was applied to both pedal bearings more or less equally. Additionally there was plenty of give in the frame and crank.
Now the only thing that can flex is the pedal spindle, due to the fact that the cleat support is some way from the crank arm. This puts a huge load, especially with heavier riders, on the outside pedal bearing(s). This in turn can cause flex in the pedal shaft if it is of insufficient stiffness.
Spindle flexing will cause problems in the bearings, which could in turn cause the pedal thread to rotate due to partial seizure.
So you folks with the pedals that come unscrewed, do they have lightweight flexi-spindles, only one outside narrow point of contact bearing, long spindles to the cleat support?
If the above theory holds up the flexing could even drain of valuable applied power overcoming the drag.
What do you think or is it me that needs to do a bit more.