Besonderheiten bei Gewinden/Austauschbarkeit bei älteren Raleigh Fahrrädern: Unterschied zwischen den Versionen

Die Breite des Tretlagergehäuses ist auch ein Unterscheidungsmerkmal. Standardmaß für britische Innenlager (mit 24 TPI Gewindesteigung ist die Breite von 68 mm. Raleigh 26 TIP Tretlagergehäuse sind im allgemeinen 71 oder 76 mm breit.

Normalerweise ist es nicht möglich, ein Raleigh Twenty freihändig zu fahren, weil die obere Lagerbuchse des Steuersatzes aus [[Nylon]] gefertigt ist (s. Bild) und eine hohe Reibung hat. Man kann Sie gegen einen gewindelosen 1 Zoll Steuersatz tauschen. Die originale obere Mutter und Kontermutter können benutzt werden, um das Lager vorzuspannen. Man sollte jedoch einen Schaft[[vorbau]] benutzen, weil der Ahead-Ser Vorbau nicht genug Raum für die Vorbauklemmung des Twenty lässt. Man muss einige [[Spacer]] und/oder Zugklemmungen einsetzen, damit man genug Säulenhöhe am Steuersatz zum Vorspannen erhält. Mehr dazu kann man bei Sheldon Brown [http://sheldonbrown.com/org//raleigh-twenty.html in seinem My Raleigh Twenty Artikel] lesen.

The forks used on most Nottingham Raleighs have keyhole-shaped axle slots. These are designed to fit Raleigh hubs, with thin (5/16") solid axles and wheel retention shoulders on the cones. The spacing between the inner faces of the fork ends is less than the modern 100 mm standard. If you wish to mount a modern hub on a Nottingham Raleigh, be prepared to do some filing on the fork ends, to enlarge the lower part of the slots to fit the modern axle. Use a good sharp file, and, if possible, have the fork end itself clamped into a sturdy vise. If you don't, vibration of the fork will make it difficult to file. Make sure you file both sides the same amount, so the axle will not go in crooked.

The fork blades should be spread to match the over-locknut dimension of the hub. The dropouts will need to be realigned as well, to avoid bending the hub axle after the blades have been spread. The fork rake of Raleigh three-speeds is rather large, and so trail is less than optimal, and unbending the fork blades a bit can improve handling. I hesitate to advise realigning a fork unless you have access to a proper jig. You could just replace the fork instead.

Most Nottingham Raleigh rear dropouts have narrow (8 mm) slots intended for the flat-sided axles common on Sturmey-Archer and other older British hubs. This still works with modern Sturmey-Archer and SRAM internal-gear hubs which have flatted axles. Most other modern rear hubs are 10 mm, some are even 10.5 mm, so you will need to file the rear as well. Shimano internal-gear hub axles are flatted, but the anti-rotation washers place the flats at an angle to the dropout slots. We recommend doing all of the filing on the bottom of the slot. This eliminates the risk of making one side higher than the other.

Dropout spacing on bikes made for 3-speed applications is typically 114 mm (4 1/2 inches). 5-speed derailer systems usually used 120 mm. Many upgrades will call for a wider dropout spacing.

The typical Raleigh-built 3-speed comes with 590 mm (26 x 1 3/8) rims, with long-reach brakes, around 75 mm at the front and 80 mm at the rear.

If you switch to 622 mm (700c) wheels, you'll need brakes with a reach of about 60 mm at the front and 65 mm at the rear (but measure -- this may vary). 700C wheels are a recommended upgrade, both for the greater variety of available rims and tires, and for better braking. Modern dual-pivot sidepull brakes with the required reach, such as the Tektro R556, will work. The larger wheels will raise the frame by 10-18 mm depending on the width of the new tires, an issue if the frame already borders on being too large.

700C wheels risk interference with the original steel fenders, but modern, adjustable plastic fenders will work fine. They also are much lighter.

If you switch to 559 mm (26" MTB size) you'll need very long-reach brakes. Such brakes are often a bit anemic due to the long arms; also, the bottom bracket will be low, reducing cornering clearance.

If you wish to use 559 mm wheels, it is often a good idea to replace the fork with a MTB fork with cantilever bosses. You then have the option of raising the front end of the bicycle, and with it the bottom bracket too, especially if you use a suspension fork. If you're handy, you can even braze cantilever mounts onto the rear. See the article on installing cantilever braze-ons. Or, you may use a home-made drop bolt.

As mentioned above, Raleigh forks are completely standard except for the thread pitch. Thus, any standard stem with a 7/8" (22.2 mm) quill will fit into the forks.

There is an issue, however, at the top end of the stem. This is not a Raleigh-specific issue, but applies to older British bikes from all makers. The handlebar clamp diameters on older British bicycles depended on the material of the handlebars, rather than what type of bars they were. Specifically, steel handlebars (and the stems made for them) used a 15/16" (23.8 mm) clamping diameter at the middle of the bar. Most Nottingham Raleighs have this type of bar/stem.

Thus, if you wish to replace the stem and keep the handlebar, the hole in the new stem will be too large to clamp properly. You can get around this by using a shim to make up the difference, though this is a bit inelegant.

The eyelets in the fork ends, where the fender/mudguard stays attach to the frame, also use a non-standard, Raleigh-specific threading. It is common to tap these out to the standard 5 x 0.8 metric size.

The location of the eyelets at the back of the rear dropouts calls for shorter fender stays than normal at the back of the fender, and longer at the top of the fender. This is not a problem with most newer fenders because they have adjustable stays.

 

The eyelet position can also be an issue with some rear luggage racks, because the legs may not be long enough to let the rack clear the top of the fender. Racks designated as being for "hybrid" bikes will usually work.

* [[Sturmey-Archer 50 Jahre führend]]

Dieser Artikel basiert auf dem Artikel https://www.sheldonbrown.com/raleigh26.html Threading/interchangeability Issues for Older Raleigh Bicycles] von der Website  [http://sheldonbrown.com Sheldon Browns]. Originalautor des Artikels ist [[Sheldon Brown]].

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