gitaneusa.com :: View topic - Vintage

joe v

Took off the cranks - no markings at all on that fixed cup; I don't have the necessary tools to remove the cups, but they look absolutely pristine on both sides (as do the bb-shells) - no exterior signs of anything having been forced, neither is there any 'play', looseness or roughness in the spindle when turned ...

verktyg

The "forced fit" would be in the threads inside the bottom bracket. The BB cups and spindle are made of hardened steel, probably around 58 Rc to 62 Rc hardness (Rc = Rockwell C Hardness scale).

By comparison, soft, fully annealed steel could be under 20 Rc and a metal cutting file is about 56 Rc.

The threads in the bottom bracket are probably no more than about 30 Rc hardness. The hardened cups could act as a thread forming tap in the softer steel of the BB shell.

A British adjustable cup can screw about 4 to 5 threads into a French bottom bracket before the thread mis-match blocks further EASY turning.

Also as I mentioned before, the BB could have been re-tapped to British threads or... VERY MUCH less likely the bike came with a British threaded bottom bracket. The headset would likely be British too.

That said, the frame pictured below is probably a 1976 Tour de France and has a British threaded fork and British BB cups. That may be because the bike came from OZ.

If there's no play in the BB spindle and it rotates smoothly then the old adage "If it ain't broke, don't fix it" applies. At some time in the future when the BB needs to be overhauled then you'll be able to figure out what was changed.

Most better quality BB cups have the thread size marked on them or have some kind of code on the fixed cups such 1 or 2 rings machined into the flat surface to indicate the thread size. Nervar French threaded fixed cups have no markings, same with most economy cups.

Additionally, going back a few messages, the picture of my blue frame (ex sandman, ex wisey) was intended to show the position of the Reynolds 531 decal on the down tube and the gold bar at the bottom of the decal. This style Reynolds decal appeared from 1974 on into the 80s.

This particular decal indicates that only the 3 main tubes were Reynolds 531. Your Reynolds decal on the seat tube states that the tubes, forks and stays were made of Reynolds 531.

In addition, this style of cutout lugs appeared several years later than the probable date of manufacture of your frame. Same thing with the semi-sloping fork crown. Your bike has a really nice Wagner fork crown that I only recall seeing on a few Gitanes.

One other possibility concerning decals, some bike shop could have replaced the newer style yellow decals with the older foil decals but not likely.

Gitane switched to new colors after they discontinued the the foil decals in 1974 plus they improved the cosmetics a little at the same time.

They dropped the aqua blue green color on your frame and brought out the deep blue color on the frame above.

Your bike is an early 74 Olympic model, I'll stick by my pronouncement on that (having never seen one in the flesh)! Mad

Chas.

joe v

Chas, thanks again for all the info. As to the fixed-cup matter : no markings on the surface at all and yes, I was going to stick to that same adage as well - for the time being. Looks like it will take a british BB then (and unscrew clockwise on the drive-side) when the time comes to replace it, or?

Joseph

verktyg

Joseph,

When it comes time to repack the BB, remove the adjustable cup, pull out the axle, clean out the old grease and inspect the threads in the BB.

Check for any sign that the threads have been stripped or damaged and the cup goes in and out easily.

You can clean the fixed cup from the left side. If the bearing race on the spindle is in good condition and the fixed cup is also good, there's no need to remove it.

I have a long pair of industrial tweezers that I use for replacing the balls through the adjustable cup side.

It's very difficult to determine whether the fixed cup is RH or LH thread. Check the headset. If it has British threads then the fixed cup is probably LH.

Hope that this helps.

Chas.

joe v

Chas,

having just discovered that someone simply shimmed a standard stem to fit the 22.0 size headset, I think it's safe to say you're more than probably right on the BB having been 'adapted' to English thread by a less than subtle approach as well! Luckily it's a very thick-walled stem, so there's plenty of thickness left; would definitely have worried me on a standard (thin-walled) stem though!

Joseph

verktyg

Joseph,

The stem looks like it's a Cinelli. Imperial size stems have 22.2mm diameter quills. Metric stems are 22.0mm.

I've seen "22.2mm" stems that ranged from close to 22.0mm to 22.3mm and metric stems from 21.0 to 22.0mm.

Same thing with the hole with the steering tubes.

BTW, an easy way to tell the threads on a steering tube:

Metric tubes are 25mm and British/Italian threads are 25.4mm in diameter.

British threaded headset parts will loosely screw on to a Metric steerer but Metric threaded parts wont even start to thread on a British threaded steerer.

BTW, the old style Cinelli stems take a 26.4mm Cinelli bar. Don't try to use a smaller diameter bar.

Chas.