Französische Fahrräder: Unterschied zwischen den Versionen

Französische Fahrräder sind oft von hoher Qualität. Sie haben jedoch ihre Eigenheiten und Probleme mit Austauschbarkeit von Koponenten. In diesem Artikel sollen die Fallen aufgezeigt werden, in die man stürzen kann, wenn man französische Fahrräder wartet oder aufrüsten will. Zu den üblichen Problemen werden Lösungsansätze aufgezeigt.

Während des ersten Fahrradbooms in den frühen bis mittleren 1970er Jahren wurden viele französische Fahrräder weltweit verkauft. Die meisten waren einfache [[10 Gang]] Fahhräder mit weichen [[Stahl]]rahmen, Stahlfelgen und [[Kurbeln mit Splintbefestigung]]. Diese einfachen Modelle waren im Allgemeinen kaum wart, weiteres Geld zu investieren, außer man hatte eine starke sentimentale Bindung zu einem solchen Modell aufgebaut. Diese Fahrräder sind gut als Transportmittel für kurze Strecken (z.B. zum Bahnhof und zurück) geeignet und es wäre nicht allzuschade, falls sie gestohlen werden.

{{Ergänzung|Anmerkung von John Allen|Ich glaube, dass Sheldon hier stark generalisiert. Manche der einfachen Modelle fahren sich sehr gut, wenn sie mit besseren Komponenten nachgerüstet werden. Ich (John Allen) bin nicht der einzige Fahrradfahrer, der das exzellente Handling des UO-8, Peugeots Einstiegsmodell der 1970er Jahre mit 10 Gängen, lobt. Es gibt sicherlich auch andere einfache französische Modelle, die genau so gut sind. Der UO-8 Rahmen hat normalerweise lange [[Kettenstrebe]]n, um reichlich Fersenfreiheit zu sorgen, wenn man einen [[Gepäckträger]] am Heck montiert. Die unkonifizierten Rahmenrohre mögen etwas schwerer sein als moderne Rahmenrohre, jedoch kann die zusätzliche Verwindungssteifheit gut unterstützen, wenn man schwerere Lasten auf dem Gepäckträger transportiert. Unkonifizierte Rogre bekommen auch nicht so schnell Dellen wie deutlich dünnere konfizierten Rehmenrohre. Ein UO-8 ist das bevorzugte Reiserad von mir (John Allen). Da hast Du's!}}

Höherwertige französische Fahrräder mit Kurbeln ohne Splintbefestigung und [[Aluminium]]felgen sind es zumeist Wert, Sie zu restaurieren und aufzurüsten. Diese Fahrräder sind oft auch gut geeignet für den Umbau als [[Fixed Gear]]. Unglücklicherweise machen es manche Dimensionen und Gewindestandards älterer französischer Fahrräder schwer, passende Bauteile für die Reparatur oder die Aufrüstung zu finden.

AVA Death Stem

Many higher-quality French bicycles of the '70's came with AVA brand bars and stems. These have a reputation for failure, and should be replaced.

French stems differ both in the size that fits into the steerer, and the size of the part that clamps on to the handlebar. Thus, if you want to replace the handlebars on a French bicycle, you will probably also need to replace the stem.

French stems are 0.2mm narrower than others where they fit into the steering column. A standard 7/8" / 22.2mm stem won't usually fit. In many cases, the limiting factor for fitting the stem in will be the headset locknut, rather than the steerer itself. Try removing the locknut before sanding down a stem. If the headset locknut is slightly tighter than the steerer, it can be enlarged easily with a small grinding wheel.

In cases where the stem really won't fit into the steerer, a few minutes' work on the stem with sandpaper will usually do the trick. Wrap the sandpaper around the stem, grip it with your hand, and turn the stem round and round until it fits. You only need to remove 0.1 mm, which is 1/250", not much at all! [This needs to be a quill-type stem, which inserts into the steerer tube, and an aluminum alloy stem, not a steel one -- from which you would be removing chrome plating, leaving it vulnerable to rust. Another approach is to replace the fork and the headset with ones with standard British/ISO dimensions. This is possible, as French head tube bearing race dimensions are 30.2mm, the same as British. You could use a standard 22.2 mm quill stem, or a threadless headset and a 1-inch Aheadset-type stem. Also, an adapter is available as of 2014 to fit a 1 1/8" Aheadset-type stem to a French fork.-- John Allen]

If you convert from a French stem to a standard one, you will also need to replace the handlebars, which are a different diameter.

The threaded parts of a French headset are non-standard, but the press-in parts are conventional. If you have a worn-out headset, it is most likely the lower races that are damaged. If you have trouble finding a French headset, you can replace the bottom races with ones from a standard headset, and keep the old parts on top.

French-thread bottom bracket cups use 35 mm x 1mm threads. They are getting hard to find. If you have a French bicycle with sound bottom bracket cups, you may want to re-use them, even if you wind up changing the axle. Since French bottom brackets are normally the usual 68 mm width, British/I.S.O. bottom bracket axles will sometimes work.

French bottom bracket cups usually have thinner walls than Japanese ones, so the bearing ridges on the spindles are farther apart. If you use a standard Japanese spindle, the adjustable cup won't be able to screw in far enough to snug up the bearings, or if it does, it will sink into the bottom bracket shell so that you won't be able to install the lockring.

The good news is that a Japanese spindle made for an Italian size (70 mm) bottom bracket will usually fit! In the J.I.S. marking system, these are the spindles that are marked with a "5" code. Spindles for 68 mm bbs have codes beginning with 3. This trick often makes it possible to upgrade an older bike from cottered to cotterless cranks, at a reasonable cost, or replace a worn French cotterless spindle that is no longer available -- but see warning below about French crank extractors.

Few cartridge bottom brackets are available in French thread, but Phil Wood retaining rings are available in French size. They work with Phil Wood bottom brackets and Shimano UN72 units. Velo Orange makes a cartridge bottom bracket which uses expanding sleeves instead of threads, and also will work in a French-threaded frame.

French-thread bottom brackets, like Italian, use regular right threading on both sides. This means that the fixed cup will have a tendency to loosen up in use. The best prevention is to make sure it is really tight. In some cases, a thread adhesive may even be called for.

Some French bicycles, notably many Motobécane models, used Swiss thread bottom brackets. These have the same thread and diameter as French, but use a left thread for the fixed cup. This makes life interesting when you need to remove the fixed cup and don't know which way to turn it. Good luck. Phil Wood and velo Orange offer the same options as with French bottom brackets.

Newer French bicycles commonly use Italian or British/I.S.O. bottom brackets.

The usual cotter diameter for French cottered cranks is 9 mm, rather than the 9.5 mm more commonly used on British and Asian bicycles.

Older TA and Stronglight cranks each had their own unique thread for for the crank extractor, and you will need to get the correct puller for the crank you are working on. TA used a 23 mm extractor, Stronglight used 23.35 mm until 1982, when it converted to the standard 22mm diameter. You must use the correct crank extractor. Be especially careful not to use a TA extractor on a Stronglight crank. It will thread in, but it may strip the threads in the crank.

Some J.I.S. Japanese spindles have studs on the ends threaded for nuts to hold the cranks in place, instead of bolts that thread into ends of the spindle. Many TA or Stronglight crank extractors do not work with a stud-end spindle, because the plunger can not be retracted far enough. You could use a gear puller (sold at auto parts stores) to remove a crank if you don't have an extractor that will work. Next time, use a bolt-type spindle!

Some French bicycles (and many early Treks!) came with Maillard "Helicomatic" rear hubs. This was the first cluster that could be removed without a big, powerful tool. It came with a cute little pocket-size tool that incorporated a spline wrench for the cassette lockring, a spoke wrench, and a bottle opener. The Helicomatic was a nice idea on paper, but poorly executed. These hubs are losers.

Both hub flanges were 1mm farther to the left than those of a normal hub, causing increased dish in the rear wheel, and persistent spoke breakage problems. Many loyal Helicomatic fans tout the ease with which the cassette may be removed for spoke replacement as a great virtue, but if the hub were better designed, it wouldn't break so many spokes!

Most of the French bicycles that flooded the U.S. in the '70's had plain rear fork ends, and used rear derailers with bolt-on adapter claws, secured by the rear axle.

French spoke gauge numbers are lower for thinner wires, while the U.S./British gauge numbers are larger for thinner wires. The crossover point is right in the popular range of sizes used for bicycle spokes:

*    U.S./British 14 gauge (.080", 2 mm) is the same as French 13 gauge

*    U.S./British 13 gauge (.092, 2.3 mm) is the same as French 15 gauge

Most French bicycles imported into the U.S. before the mid '80's used 630 mm (27 inch) wheels. This size was never in use in France, and was only supplied on export models.

 

*   Sport bikes would use either tubulars or 622 mm (700 C) clinchers.

*   Utility bikes, loaded tourers and tandems would generally come with the 584 mm size commonly known as 650 B or "demi-ballon." This latter size has traditionally been quite difficult to find in the U.S., and is an endangered species in France. Schwinn used this size on a few MTB models. In Schwinn nomenclature, it is called "26 x 1 1/2".

*   Some French folding bikes use 490 mm (22 X 1 3/8") tires. There are also several other specific French sizes used mainly on juvenile bikes.

For more detailed tire size information, see my article on Tire Sizing.

[[Kategorie:2008]]