A ratio of unitless measure? How could something be measured if there are no units to measure?


actually yes, in engineering there are lots of instances where dimensionless number appear. when you want to find your gear ratio, by dividing your chainring by your cog, that is a unitless value. the units cancel out. its pretty common


OK. How much does it oscillate? At what amplitude? At what frequency? For what duration? What mode do they oscillate... radially, laterally?


the ocsillate radially when absorbing impulses. asking for specifics like whats the amp, freq, etc it a bit rediculous. they can be determined if you have a laboratory take measurements, or you can simulate it on an assortment of programs.


OK. So how long will any bicycle wheel, when it impacts a stationary object, oscillate. With the load of a bicyclist on it? And a compliant rubber tire between the rim and the ground?


from my experience with mechanical/electrical control systems the settling time of damped oscillations will vary greatly from system to system. bridges for instance can have very high settling times with a high percent overshoot, while electrical and other mechanical systems will have a settling time in milli or micro seconds.


OK. In the case of a bicycle wheel, on a bicycle, with a rider, suspended by a pneumatic tire, how long will the twisted spoke wheel oscillate compared with, say a 3x laced wheel?


thats what this whole thread is about... dont you know?


The twisted spoke thing gets tossed around usenet every once in a while, with some adherents anecdotally claiming it makes for a stiffer wheel. And generally debunked by the likes of Jobst Brandt.

It seems for even the most oscillation prone wheel (and I'm not convinced that oscillation is at all a issue for any reasonably built wheel), the very weight of a rider and damping of a air filled rubber tire would make oscillation a non issue. With all due respect to Schraner, the "highly praised damping effect" sounds like pseudoscience.

whether oscillation IS an issue, its still there no matter what. but IMO theoretically the damping ratio is effected, but whether it relates physically, who knows. all i know is that twisted spokes look cool