Motobecane project of mine.

I got my old Motobecane out and fixed what I could today and even rode
it a bit, to find all the sqeaks and things that needed attention. All
is well except for a few odds and ends. One is stopping me from riding
it at all. The left pedal was bent and falling apart and had to be
surgically removed with the help of a Dremel carbide grinding disc.
After getting the pedal unscrewed I find that not only is it a reverse
thread (left side) but it appears to be a non-standard size. I have some
pedals from newer childrens bikes but they are a smaller diameter than
even my Mongoose and slip right on through. A pedal from my Mongoose or
Schwinn Super Sport 'looks' like the correct thread but will only just
engage and then binds. Does anybody know what a 1950-1960s Motobecane
would be likely to use? This bike is entirely European with non-drop
bars and 27" x 1 3/8 tires. It also uses the pin attach for the cranks
so I was able to use an old Schwinn vintage 1960s crank on the right
side, but had no such thing for the left. I am trying to get this bike
fixed up as a ridable museum piece, for lack of a better description.
The tech group might ask me why am I bothering. Even the 9 year old brat
next door said why am I working on junk, that he has new bikes. I don't
think he would have bought the Chinese junk thing I was about to lay on him.
Any help appreciated. E-bay or a junk shop is a last resort.
Bill Baka

"b_baka" wrote:

Schwinn Super Sport [pedal] 'looks' like the correct thread
but will only just engage and then binds. Does anybody know
what a 1950-1960s Motobecane would be likely to use?

A French bike of that era will have metric pedal threads - 14mm x 1.25mm.
That's close, but not close enough, to the modern 9/16" x 20tpi standard,
as you found out.

Your best bet is probably to replace the left crank with a non-French one.
Alternatively, you might be able to have the crank rethreaded.

Sheldon Brown has a useful page on older French bicycles that lists some of
the other incompatibilities you might encounter:

http://www.sheldonbrown.com/velos.html

James Thomson

James Thomson wrote:
"b_baka" wrote:


Schwinn Super Sport [pedal] 'looks' like the correct thread
but will only just engage and then binds. Does anybody know
what a 1950-1960s Motobecane would be likely to use?


A French bike of that era will have metric pedal threads - 14mm x 1.25mm.
That's close, but not close enough, to the modern 9/16" x 20tpi standard,
as you found out.

Your best bet is probably to replace the left crank with a non-French one.

I did that on the right side since I had a Schwinn with a bigger set of
gears that had the pin lock mount style. The original crankset was too
small so it was not a loss there. Unfortunately I have the bad habit of
only keeping the right crank with the gears and not the left, which
today proved, will be needed when you least expect it.

Alternatively, you might be able to have the crank rethreaded.

Sheldon Brown has a useful page on older French bicycles that lists some of
the other incompatibilities you might encounter:

http://www.sheldonbrown.com/velos.html

James Thomson



Thanks,
I always seem to be getting sent back to Sheldon Brown.
The bike does ride OK for an antique so now I am in a bit of a hurry to
get that last part done, with only the shifters to go, so single speed
for a while.
Going there now.
Bill Baka

Bill;

Have an old (real old) Gitane that I'm trying to get rid of. The cranks are
likely to fit (cotterpin cranks were OSFA?) and a pair of pedals come with.
You could re-build your pedals on the Gitane pedalshafts if the pedal
chassis aren't beat up too badly. Perhaps the Gitane pedals would fit your
Motobecane cranks? In any case, having an extra set of cranks and spare
pedals is a Good Thing if you intend to make your museum piece a daily
rider.

Brian

bouce me back, if you're interested...

Brian Sanderson wrote:
Bill;

Have an old (real old) Gitane that I'm trying to get rid of. The cranks are
likely to fit (cotterpin cranks were OSFA?) and a pair of pedals come with.
You could re-build your pedals on the Gitane pedalshafts if the pedal
chassis aren't beat up too badly. Perhaps the Gitane pedals would fit your
Motobecane cranks? In any case, having an extra set of cranks and spare
pedals is a Good Thing if you intend to make your museum piece a daily
rider.

Brian

bouce me back, if you're interested...


Brian,
I'm in northern Cal. Where are you?
Bill