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Threading/interchangeability Issues for Older Raleigh Bicycles

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by Sheldon "Nottingham" Brown
revised by John "Sure, would" Allen
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Raleigh Threading

The Raleigh bicycle company is one of the oldest in existence, going back to the early years of the 20th century. Back then, screw threads and other dimensions were not standardized to the same extent that they are now. Each manufacturer would develop its own proprietary "standards."

Over time, this caused so much confusion and difficulty that it led to a gradual movement toward industry-wide (or at least nationwide) standardization. In Great Britain, most of the builders wound up standardizing on the dimensions used by B.S.A. (Birmingham Small Arms), an important bicycle and firearms maker in the early 20th century. Indeed, the B.S.A. standards became adopted as the "B.S.C." (British Standard Cycle) dimensions, and ultimately formed the heart of the ISO international standard in use today.

At the time of this transition, Raleigh was the Microsoft of the bicycle industry, and did not choose to go along with the adoption of B.S.A./B.S.C. standards. Right through the 1990s, the bikes built at the mighty Nottingham Factory were made to Raleigh proprietary dimensions. Since Raleigh made virtually every part of these bikes, there was no compelling need to match standards used by other manufacturers. (We shouldn't be too hard on Raleigh about this. Making the change would have been very, very costly, and wouldn't have benefited the shareholders in any way.)

The main difference is that most B.S.C./ISO screw threads have a pitch of 24 threads per inch (TPI), while the corresponding Raleigh parts have a slightly finer 26 TPI threading.

How to tell the Raleighs from the others

raleigh dropout

The easiest way to identify Raleigh-built bikes is by looking at the rear dropouts. Almost all Raleigh-threaded bikes have the rear fender eyelets located directly behind the axle, instead of above it. (This doesn't apply to roadsters, which don't generally have dropouts or fender eyelets.)

Most Raleighs use a seatpost diameter of 1" (25.4 mm) while other British 3-speed bikes usually use 1 1/16" (27.0 mm)

Some sporty models have more conventional dropouts, but you can identify these by the distinctive Raleigh headset and bottom bracket cups.

The width of the bottom bracket shell is also an indication. Standard British (24 TPI) bottom bracket shells are 68 mm wide, give or take a mm. Raleigh 26 TPI shells are generally 71 mm or 76 mm wide.

Cottered Cranks=Raleigh 26 TPI Threading

In later years, higher-end Raleigh models such as the International, Professional, Competition, Grand Sport and other models built at the separate Carlton workshop used B.S.C. threading, as did models made in Asia and the United States. These bicycles all used cotterless cranks.

Generally speaking, Raleighs that use cottered cranks have Raleigh 26 TPI threading for both the bottom bracket and the headset. These include all Nottingham-built bicycles sold with a coaster brake or internal-gear hub, as well as lower-priced derailer-equipped models up through the Super Course, which had a frame of plain-gauge Reynolds 531 tubing. Although the diameters are the same as B.S.C., the different thread pitch makes the parts incompatible. This article will provide strategies for getting around this problem.

 

Upgrade or Restore?

With an older bike, there is often a question of whether to preserve it for posterity in "original" condition or to upgrade it for use. The answer to this question generally depends on rarity, age and condition.

Nottingham Raleighs were built in huge numbers, and they were so well-made that quite a lot of them have survived, so most of them don't really qualify as "rare."

Very few English bikes were imported to the U.S. before World War II, so it is unusual to see really old ones. That said, I'd generally consider anything from the 1960s onward to be fair game, with 50s bikes on the borderline. (I have a separate page about dating your Raleigh bike.)

To be a good candidate for restoration, a bike should already be basically complete, and free from rust.

Note that these issues are a moving target, and will change over time as these bikes become increasingly rare. I think of my father, who grew up tinkering with Model T Fords. When he was a young man, old Model Ts were basically throwaway cars, cheap and plentiful. Hot-rodding or otherwise modifying them was a popular avocation, and perfectly reasonable at the time...even though, now, a complete, original Model T is worth big bucks.

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Raleigh Bottom Brackets

DESCRIPTION

Raleigh bottom-bracket cups have raised ridges on their surfaces, which fit a 5/8" or 16 mm open end wrench. The best tool for them is the Park HCW-11 (TL7063). For information on servicing the stock cottered setups, see my articles on:

Upgrading to Cotterless Cranks

There are three ways to upgrade a Nottingham Raleigh to use modern cotterless cranks:

New Spindle, Old Cups

By far the cheapest option is to keep the original 26 TPI Raleigh cups, and install a new spindle with the tapered square ends needed to fit cotterless cranks. Because the inside diameter of the bearing cups is slightly smaller than for other brands, not all spindles will fit, unfortunately, unless you replace the standard 1/4" bearing balls with 15/64" or 6 mm bearing balls. Bicycle shops do not usually stock these sizes, but Internet vendors carry them.

You must check the fit of bottom-bracket spindle, bearing balls and cups before installing the bottom bracket. If the bearing tracks run too low on the spindle, the bearings will wear quickly.

Place some grease in the bearing cup, then assemble the parts, as shown in the photo below. Rotate the spindle, then take it out and examine it.

axle bearings assembled

The next image shows the bearing track too low, as is usual with a JIS spindle and Raleigh cups. The bearing balls actually ride on the little ledge on the low side of the bearing area of the spindle. This also pushes the bearing cup outwards and can deceptively look like a good fit in a wide Raleigh Twenty bottom bracket.

Bearign track too low

The next image shows a correct fit using 6 mm bearing balls and a JIS spindle. The bearing track is in the middle of the bearing area of the spindle.

Correct bearing track

Raleigh cups are no longer made, but they are extremely hard. Used cups in good condition may often be salvaged from a trashed frame.

Raleigh bottom bracket shells are wider than the standard 68 mm width of B.S.C./ISO bottom brackets, commonly anywhere from 71 mm to 76 mm. As a result, you'll need a longer-than-normal spindle. Japanese JIS-standard spindles are generally designated by a simple code consisting of a single digit followed by one or more letters.

You may check whether the assembly is wide enough by holding it up next to the bottom bracket. The combination that seems to work best is a 7 series spindle with 6 mm bearing balls, in a 71 mm bottom bracket. You could also install a crank loosely to run a quick check on the chainline.

Checking BB width

Just getting a spindle to fit into the frame is a start, but you may still have problems due to the overall length of the spindle. Older cranks used longer spindles than newer, "low profile" cranks. JIS axles are mostly available in longer overall lengths, which are likely to give poor chainline with newer cranks, though they will work. If you are spreading the rear dropouts of a frame to use a wider hub, you may want to increase the chainline anyway.

See my article on Bottom Bracket Sizes for information on spindle lengths for different cranks.

Cartridge Bottom Brackets

Modern cartridge bottom brackets are much easier to install than the old-style cup-and-cone design. There are three possibilities for running a cartridge bottom bracket in a Raleigh 26 TPI shell:

Re-tapping to B.S.C./ISO

This option is the most versatile, but also the most drastic. Only the top bike shops will have the necessary guided tap set required for this. The threads will not be as strong as they would be if the shell was made for standard threading, but this approach generally works well. You will still need to deal with the overall shell width. A shop that has the correct taps will also have the correct tool to face the ends of the shell, and this tool can be used to bring the width down to a more standard size (though it takes a lot of elbow grease! Beware, though, the welds to the bottom bracket shell of a Raleigh Twenty can be very hard, maybe harder than the taps.

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Raleigh Headsets

raleigh-headset

As with the bottom brackets, Raleigh differs from B.S.C./ISO in using 26 threads per inch instead of 24. Fortunately, all of the other mounting dimensions are the same between the two systems. The stock Raleigh headsets have proven to be unusually long lived, so it will rarely be necessary to replace one, unless you wish to install a non-Raleigh fork.

You can even mix and match. If your Raleigh headset cups are worn out or rusted on the load-bearing bottom section, you can replace just the bottom with any standard ISO 1" headset parts, and re-use the Raleigh upper assembly.

You can make it possible to ride a Raleigh Twenty no-hands by replacing the Nylon sleeve-bearing upper headset with a 1" threadless upper headset, such as the Aheadset. The original Raleigh top nut and locknut can be used to preload the bearing. You will need use a quill stem because the Aheadset does not leave enough room for the Twenty's stem clamp. You will need to add spacer washers and/or a cable stop to get enough headset stack height to preload the headset bearings. There's more about this on the Raleigh Twenty page.

Fork Ends/Dropouts

 

Brake Reach

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 my article on installing cantilever braze-ons. Or, you may use a home-made drop bolt.

The Raleigh Twenty has special brake-reach issues, as it was sold with either of two different wheel sizes.

Handlebars/Stems

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.

If you want to replace the handlebar, you should really replace the stem too, because it is unsafe to overspread the 15/16" stem to fit a standard 1" (25.4 mm) handlebar.

 

Fenders/Mudguards/Racks

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 .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.

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Links:

English 3-Speeds

Retro Raleighs

Raleigh Parts Threading/Interchangeability

Three-Speed Parts from Harris Cyclery

Sturmey-Archer Hubs

Sturmey-Archer Brochures 1935-38

You'll need a fast connection for this.

Sturmey-Archer 1902-1952

Evolution of the Raleigh Sports

The Raleigh Twenty

Some of My Raleighs:

New! Sturmey-Archer Heritage Site

Martin Hanczyc's roadster pages.

Tony Hadland's Sturmey-Archer Pages

Tony Hadland on the history of Raleigh

Thanks to Brandon Davis, Russ Fitzgerald and Martin Hanczyc for providing some of the data points for this page.

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