<
[email protected]> wrote in message
news:ubwIa.3962$%[email protected]...
> Kraig Willett writes:
> > What would be good info to have would be the actual EI data for forks (at least every inch or so
> > along the length) so that fork leg curvature and its effects on wheel deflection could be better
> > quantified.
>
> That isn't interesting for the question at hand, that of wheel deflection and its ability to take
> such loads. By making it so all encompassing you make it so difficult that it won't be done at
> all, leaving us with a dangling question.
Fair enough. However, you were the one that suggested the experimental determination of the fork
effect. I am simply suggesting a more rigorous method of doing the task that you suggest.
From what I have seen and read, no one has actually gone to the trouble of actually doing what I did
on my apartment floor a couple of years ago for a completely separate purpose than what is being
discussed in this thread. I am trying to utilize this data for the purposes of this thread. I have
made the data and methods available for critique - have at it!
You have still not commented on the methodology I employed/ assumptions I made when trying to
estimate dynamic side loads based on measured static and dynamic deflections. Until that is
addressed we really can't progress any further. I am unconvinced that all of the deflection I
observed is from a pure side load - are you convinced that it is?
> > This type of data is more difficult to come by than slapping a $10 dial indicator and some band
> > clamps on my bike.
>
> Let's just isolate the variables. Determine the deflection as measured at the fork crown for the
> same side loads on the tire and on the axle. This would enable separating fork flex from
> fork-wheel flex.
Address the potentially poor assumptions I used in my experiment, then we can move forward with
separation of the variables to determine relative contributions. I executed a protocol, which to me,
seems reasonable (admittedly with poor instrumentation) for determining dynamic side loads.
Point out the deficiencies in my process, methods, instrumentation.
For me, the contribution of this particular fork doesn't really matter since it was held constant
for the several different wheels tested. The magnitude of the flexible boundary condition was
interesting to me having a large amount of experience testing wheels in a similar manner as Damon
Rinard (fixed boundary condition).
IMHO, fixity-ness plays a huge role in wheel deflection - just as it does in the beam equations.
As far as lateral wheel strength goes, you have addressed this already. Your experience (from what I
selectively remember reading) is similar to my lab and field test experience.
--
==================
Kraig Willett www.biketechreview.com
==================