"Educational" is a very gentle way to phrase it, Jerry.
There were indeed two different dimensions used for at least some of the Stronglight cottered axles and cranks.
Those intended for British dimensioned crankarms - for the export market (presumably with British pedal threads, too) - used 5/8" axles to match the British bores. French domestic axles were 16 mm. diameter which is ever so slightly larger to match a 16 mm bore on their crank arms.
There is just enough difference that the French axles will not fit into the smaller British crank arm bores... I don't know if this is making any sense or whether this is your particular issue.
Here are some photos of a very nice old Stronglight crank set:
http://www.flickr.com/
Notice the photo showing the two axles alone. You can see an "A" prefix stamped into the longer axle. This stood for "Anglais" (English) and the diameter differs from the standard French axle beside it. In this case it is a slightly loose fit into the French crankset and the shorter French axle is a noticeably nicer fit.
To complicate matters even further, by the 1970s, I know that at least NERVAR was making cottered cranks for either: French axles & pedals ... British axles & pedals... AND... combinations of BOTH - on the same crank arms! So, if you were cheap (or insane) you could cobble together a crank and pedal set with a variety of parts which you simply had on hand in your shop... and then drive the next owner nuts trying to figure out what they had on the bike.
It is also possible that with the particular chainring set you are using, the crank arms required a slightly longer Stronglight double length axle. There were a couple lengths available, and I assume this would be for different "styles" of double chainrings which could be fitted - to either the 3-arm or the 5-pin steel cottered cranks.
Again, refer to the photos to see how the outer chainring on this particular example seats the outer chainring on the same plane as the 3 arms,... although fitted with the additional 6-pin bridges.
Some chainrings, if fitted directly to the "insides" of the three crank arms would have required additional spacers between the rings - which would have pushed the chainrings further inward toward the chainstay.
So many confusing variables... Oui?
BOB HANSON, ALBUQUERQUE, NEW MEXICO, USA
-------------------------------
Jerry Moos a ecrit:
Well these pre-60's projects are always educational, though maybe "fun" only if one has a masochistic bend.
Tore down the BB today on the 1954 Duravia. This went surprisingly smoothly. With the cottered BB cleaned, greased, reinstalled and adjusted, checked the fit of the old slender Stronglight steel cottered crank I plan to use. The Stronglight arm would not go on.
Searching the parts bin, found a Stronglight BB (missing the fixed cup) bagged with a different Stronglight cottered crank. Happily, the Stronglight axle worked with the cups in the Duravia. However, the original Stronglight crank I tried would not go on the Stronglight axle either. The Stronglight arm the axle had been bagged with did go on, but there was not enough chainstay clearance for the double chainrings. And even this Stronglight arm would not go on the original axle from the Duravia frame.
Sutherland's is no help here, as it implies all French cottered BB's used basically the same axle dimensions. But clearly Stronglight themselves used two different cottered axle diameters, and neither one is the same as the unknown brand BB in the Duravia, which one presumes is French made - at least it's French thread.
Does anyone understand this? Did Stronglight use two different axle diameters for cottered steel arms that appear to be otherwide identical? Were both different from typical French cottered axle diameter?
Anyone have for sale a double-length Stronglight cottered BB?
Regards,
Jerry Moos Big Spring, Texas, USA
**************An Excellent Credit Score is 750. See Yours in Just 2 Easy Steps! (http://pr.atwola.com/promoclk/100126575x1222377040x1201454360/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=62&bcd=Jun eExcfooterNO62)