In an off-list email, Joel Metz suggested to me that there was originally some sort of guard disk on the bike. Since it seems a bit silly (in my estimation) to needlessly remove the guard, I couldn't rule out that the guard was replaced by a chainring as an "after-market" modification. That is, I don't think the original owner of this bike looked for Shimano's guideance regarding gearing setups. :-)
Considering the chain stay length, and the mere 3 sprockets on the freewheel, I thought it might be possible to use the small chainring without experiencing any interference from the larger chainring. But I'm merely speculating here, based on the photo. Obviously, I don't know for sure_. Sometimes you have to take a wild guess, just for the pleasure of it...
As for shifting with one's fingers while on the move... Riders
really did this? And for up-shifts as well as down-shifts?
I'm speechless.
Cheers,
Fred Rednor - Arlington, Virginia (USA)
> Richard , Dale , Ray, ....listers,
> having tapped into Norris's vast knowledge, and Frank Berta
> on things 'Francais,' i found that many prewar touring
> machines even with Triple rigs didn't have any mech at the
> chainwheels, they apparently tapped/moved the chain in with a
> deft finger, toe or a stick. i have done so on the move with
> my toe but its a practised art ...i didn't risk any digits,
> seems that this action would be more difficult with the
> reverse ring set up in this instance...... nice machine Ray,
>
> Willie Carton, from Coleraine N. Ireland
>
> r cielec <teaat4p@yahoo.com> wrote: Ahoy !
> OK - Seven blind men and the elephant speculation re: chain
> rings.
>
> Would how this rear mechansim pivots outboard vs. inboard
> affect chain ring location ?
>
> Richard Cielec
> Chicago, Illinois; U.S.A.
>
> Fred Rafael Rednor wrote:
> Dale,
> I was so intrigued by this bike - and so surprised by the
> crankset - that I spent a long time studying the photos.
> Which
> is to say that the chainrings _appear_ to be assembled in the
> correct sequence. You have to look very closely as the shape
> of the mounting "tangs" on the rings, as well as the munting
> bosses on the inside of the crank arms.
> Here's my theory: since there's no front derailleur on this
> bicycle, the chain is moved from ring to ring - by hand -
> when
> the bike is stationary. In this sort of situation, I think
> the
> task would be more easily performed when the smaller ring is
> on
> the outside. Also, is it possible that the crankset came with
> only a single chainring and that the smaller ring was added
> later? Or was there once a front derailleur that has been
> removed and misplaced over the years?
> Cheers,
> Fred Rednor - Arlington, Virginia (USA)
>
> --- oroboyz@aol.com wrote:
>
> > Very, VERY neat bike, Ray! Thanks for showing it to us.
> >
> > I have never heard of that marque but obviously a pretty
> > unusual early aluminum model.
> >
> > Looks like maybe the chain rings were reassembled at some
> > point in reverse?
> >
> > No obvious marks from f. der mounting so I have no idea on
> > that count.
> >
> > I am interested to see what others say.. (I love this list
> > just for such moments!)
> > Dale Brown
> > Greensboro, North Carolina USA
> >
> >
> > -----Original Message-----
> > From: rgoudey@mac.com
> > To: classicrendezvous@bikelist.org
> > Sent: Tue, 13 Feb 2007 4:32 PM
> > Subject: [CR]Metal Aviation Duravia
> >
> > Newbie question here.
> > I primarily collect Balloon Tire bikes from the late 30's
> to
> > the early 40's.
> > But I am becoming interested in the touring bikes that era
> > (approximately).
> >
> > Getting to my question. I recently picked up a "what
> appears
> > to be" a
> > French touring bike. The head tube badge reads Metal
> Aviation
> > Duravia.
> > The seat and the grips were replaced as the brake cables
> and
> > shoes.
> > Any information about this bike would be greatly
> appreciated.
> > Year made? It looks like early 50's ?
> > Correct seat? Ideal...if so what model?
> > Type of grip?
> > Light? Is it missing a bezel?
> > Would it have had a Simplex Front Derailleur?
> > I have the aluminum guard that mounts to the chain
> ring.(not
> > pictured)
> >
> > Click on link for pictures.
> > http://homepage.mac.com/
> >
> > Thanks for time,
> > Ray
> > --
> > Ray Goudey Illustration
> > 4017 Crescent Point Rd.
> > Carlsbad, Ca 92008
> > 760-729-8173
> >
> >
> > _______________________________________________
> >
> >
>
________________________________________________________________________
> > Check out the new AOL. Most comprehensive set of free
> safety
> > and security tools, free access to millions of high-quality
> > videos from across the web, free AOL Mail and more.
> >
> >
> > _______________________________________________
> >
>
>
>
>
>
____________________________________________________________________________________
> Bored stiff? Loosen up...
> Download and play hundreds of games for free on Yahoo! Games.
> http://games.yahoo.com/
> _______________________________________________
>
>
>
> ---------------------------------
> Never miss an email again!
> Yahoo! Toolbar alerts you the instant new Mail arrives. Check
> it out.
>
> _______________________________________________
>
>
>
> ---------------------------------
> Copy addresses and emails from any email account to Yahoo!
> Mail - quick, easy and free. Do it now...
>
> _______________________________________________
>
____________________________________________________________________________________
Need Mail bonding?
Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users.
http://answers.yahoo.com/