"Carl Fogel" <
[email protected]> wrote in message
news:[email protected]...
> "onefred" <
[email protected]> wrote in message
news:<
[email protected]>...
> > "carlfogel" <
[email protected]> wrote in message
> >
news:[email protected]...
> > > Onefred wrote:
> > > > "carlfogel" <
[email protected]> wrote in message
> >
news:XUS_-
> > > >
> >
[email protected]:
[email protected]
> > > > etserver.com...
> > > > > Wayne Pein wrote:
> > > > > > from velonews.com Wayne Stetina, Shimano's R&D manager,
says,
> > "If
> > > > > > you remove the chain when it is only halfway worn out and
flip
> > it
> > > > > > over," he says, "you will double your chain life." In other
> > words,
> > > > > > your chain will now be turned inside out. The other side of
the
> > > > > > rollers will now contact the gears, and the derailleurs will
now
> > > > > > be laterally bending the chain the
> > opposite
> > > > > > direction. Stetina says that Shimano engineers discovered
this
> > > > > > phenomenon quite by accident. Any credence to this crud?
Wayne
> > > > >
> > > > >
> > > > >
> > > > > Dear Wayne,
> > > > >
> > > > > Oh, what a fool I've been!
> > > > >
> > > > > By heavens, next time that I measure my chain to see if it's
worn
> > out,
> > > > > I'll try measuring it from the other end.
> > > > >
> > > > > Carl Fogel
> > > > It would be interesting to see if the chain measures different
lengths
> > > > by seeing how far each side wrap around a cylinder. Dave
> > >
> > >
> > >
> > > Dear Dave,
> > >
> > > I could measure no difference when I looped my handy badly worn chain (about 1.4%) both ways
> > > around the base of a 36-inch circumference
cable
> > > drum on a flat surface.
> > >
> > > The marks made opposite the center of the start and finish pins still matched as closely as I
> > > could align them.
> > >
> > > This is unsurprising. Rollers presumably roll.
> > >
> > > It seems unlikely that any difference in length could be observed by wrapping the chain around
> > > gears, since the gear teeth remain an inch apart, even during wear.
> > >
> > > Carl Fogel
> >
> > But Carl, Wayne never said to use a badly worn chain, only one that's "halfway" worn. To me this
> > means a slightly worn chain that is still
quite
> > useable. Using a badly worn chain I don't doubt your findings.
> >
> > Dave
>
> Dear Dave,
>
> My guess is that if the strange wear pattern suggested in this thread doesn't show up on a badly
> worn chain, then it won't show up on a slightly worn chain, either.
>
> You can test this a fortiori theory by removing your current chain, wrapping it around any large
> circular object on a garage floor, and marking where the start and finish pins end up with a fine-
> point sharpie.
Well, my current chain has been removed and installed several times without paying attention to how
it was intalled and re-installed, etc. With my next chain I will pay attention to this issue and see
if I can measure a difference. Also, the direction the chain is coiled around the cylinder will
matter. Because of the chain line, one side of the chain will have greater wear than the other (rear
& left of the rivet passing over the cassette, front & right of the rivet passing over the crank).
> I used a handy cable spool, but a plastic bucket lid will do nicely. Flip the chain over and see
> where the pins end up. A chain worn to 1/32" per foot is mildly worn and would be 3/32" longer
> than a new chain over 36 links, an easily noticed difference.
>
> I expect that, after flipping, any chain's length will be indistinguishable over a three foot
> span. It's necessary to flip and measure the same 36 links, since there are in fact measurable
> wear differences between different sections of the same chain.
>
> If I'm wrong, then someone should be able to draw a quick free-hand diagram of either a bushed or
> bushingless chain showing an asymmetrical wear pattern that would somehow change a chain's length
> (or some more subtle dimension) when curved one way and then reversed.
I swear I will try to give this some thought on my next chain. I am curious to know if this truly
is a valid argument. If true, I don't think there will be a doubling of chain life or anything
dramatic like Chris Zacho thinks there will be but anything is better than nothing (when a chain
costs $20-$35).
> Here's a link to a chain diagram to get the artists started:
>
>
http://www.vikinginternational.com/about.htm
>
> I'd be glad to host any pictures, whether they make sense to me or not--just email me.
>
> Carl Fogel
Dave
