Most disappointing vintage-parts purchases are good parts that don't fit. A 1970s or 1980s road frame can be English, Italian, French or Swiss threaded, spaced from 120 to 130 mm at the rear, and built around a freewheel or a cassette hub. Measure your bike, match the numbers below, and ask the seller for any dimension a listing leaves out.
Freewheel or cassette
A freewheel screws onto threads on the right side of the hub and carries its own ratchet. A cassette slides onto a splined freehub body, and the ratchet is part of the hub. You can't use one in place of the other without changing the hub.
- Shimano Uniglide was Shimano's original cassette system, used until the late 1980s. The smallest cog screws on rather than sliding onto a spline, and all the splines are the same width.
- Shimano Hyperglide replaced it. Every cog is splined, one spline is wider than the rest, and a lockring holds the stack together. Older Uniglide cogs fit a Hyperglide body. Hyperglide cogs won't fit a Uniglide body unless you grind off the wide spline.
- Dura-Ace was the exception. On older Dura-Ace Uniglide hubs, the threaded top cog used a different thread from other Shimano models so it could be an 11-tooth cog. Those hubs need Dura-Ace-specific top cogs or freehub bodies. Keep that in mind before you buy a Dura-Ace 7400 hub set to supply spares for a non-Dura-Ace bike.
- Campagnolo 8-speed cassettes use a different spline pattern from Campagnolo's later 9- and 10-speed hubs. Campagnolo also spaced its 8-speed cogs 5.0 mm apart, against Shimano's 4.8 mm. So Campagnolo and Shimano 8-speed cassettes won't index with each other's shifters, even where you can get one onto the other's hub.
Freewheel threads vary too. ISO, older British and Italian threads are all about 1.37 in x 24 tpi and generally interchangeable. French hubs and freewheels use 34.7 x 1 mm. A French freewheel may start onto an ISO hub and then bind, and an ISO freewheel on a French hub only catches the tops of the threads and can strip. Never force a freewheel on.
Rear dropout spacing
Measure the gap between the inside faces of the rear dropouts. These are the usual figures for derailleur road bikes:
- 120 mm: 5-speed freewheels, plus SunTour's narrow-spaced Ultra 6.
- 126 mm: 6- and 7-speed road.
- 130 mm: 8-speed and later road.
A steel frame can be cold set, which means bending the stays to a new width. On steel that's a routine job for a frame builder or an experienced mechanic. Don't cold set aluminium, titanium or carbon. If a magnet won't stick to the frame, leave the spacing alone and buy a hub that fits it.
Bottom bracket threading
- English (BSA/ISO): 1.37 in x 24 tpi, usually in a 68 mm shell. The fixed cup on the drive side is left-hand threaded, and the adjustable cup is right-hand.
- Italian: 36 mm x 24 tpi in a 70 mm shell. Both cups are right-hand threaded, so the fixed cup can unscrew itself in use and has to be tightened very firmly.
- French: 35 x 1 mm in a 68 mm shell. Both cups are right-hand threaded.
- Swiss: the same 35 x 1 mm thread as French, but the fixed cup is left-hand threaded.
To identify a shell, start with its width: 70 mm points strongly to Italian. Thread sizes marked on the old cups settle it. Otherwise try a known cup by hand. French and Swiss shells look the same, and only the direction of the fixed cup's thread tells them apart.
Spindle taper matters too. Campagnolo and most older European cranks use the ISO square taper, while Shimano uses JIS (older Dura-Ace excepted). An ISO crank on a JIS spindle sits about 4.5 mm further out, and a JIS crank on an ISO spindle about 4.5 mm further in. Mixing them often works if you choose the spindle length for the chainline, so check before moving a Nuovo Record crankset onto a Shimano bottom bracket.
Pedal threads
The standard for adult cranks is 9/16 in x 20 tpi, and the left pedal is reverse-threaded. Older French cranks used 14 x 1.25 mm, and French-thread pedals are often stamped D (right) and G (left). Don't try to thread French and non-French parts together.
Headsets
- ISO/Campagnolo 1 in: 24 tpi, a 26.4 mm crown race and 30.2 mm frame cups.
- Italian 1 in: also 24 tpi, but the threads are cut at 55 degrees. An ISO headset can still be used.
- French: 25 x 1 mm threads on a 25.0 mm steerer, with a 26.5 mm crown race (sometimes 27 mm).
- Raleigh: 26 tpi, with a 27.0 mm crown race.
Stems, bars and seatposts
A quill stem for a 1 in threaded steerer is 22.2 mm (7/8 in). French stems are 22.0 mm, 0.2 mm narrower, so a French stem is loose in a standard steerer and a standard stem is too big for a French one.
Handlebar clamp sizes:
- 25.4 mm: the ISO size, used on many drop bars.
- 26.0 mm: the Italian standard, used by most Italian bars and stems.
- 26.4 mm: older Cinelli and Cinelli copies. Cinelli moved to 26.0 mm in 1998.
- 25.0 mm (and 23.5 mm): old French sizes.
A pre-1998 Cinelli Giro d'Italia bar belongs in a 26.4 mm Cinelli stem like the 1A. Other Italian bars and stems, such as the 3ttt Competizione and Mod. 1, are normally 26.0 mm, but measure before you pair them. Forcing an oversized bar into a clamp can crack it.
For seatposts, measure rather than guess. The size is often stamped low on the post. Quality steel frames with 28.6 mm seat tubes often take 27.2 mm, but thicker tubing takes smaller posts: 27.0, 26.8, 26.6, 26.4 mm, and Sheldon Brown's database lists a 1963–73 Cinelli Super Corsa at 26.2 mm. French seat tubes are 28 mm outside, so French posts differ again. Front derailleur clamps follow the seat tube too: 28.6 mm on most non-French steel frames, 28 mm on French ones.
Derailleur capacity and largest cog
A rear derailleur's total capacity has to cover (big chainring minus small chainring) plus (largest cog minus smallest cog). A 52/42 crank with a 13-21 freewheel needs 10 + 8 = 18 teeth, which any road derailleur handles. A 52/42/30 triple with a 12-28 needs 22 + 16 = 38. Separately, every derailleur has a largest cog it can clear.
- Shimano rated the Dura-Ace 7400-series rear derailleurs at 26 teeth total capacity.
- Disraeli Gears records the SunTour Superbe Pro 5200 with a 26-tooth maximum cog in its first version and 23 teeth in a later, lower-slant version. Check which one you're buying.
- The Nuovo Record is usually quoted at about 26 teeth, but that's shop lore rather than a Campagnolo specification.
Friction versus index shifting
Friction shifters work with anything, as long as the derailleur has the range. Indexing only works when the shifter's cable pull, the derailleur's movement and the cog spacing were designed together.
- Dura-Ace made before 1997, which includes the 7400 series, used a shorter cable pull per click than other Shimano groups. Dura-Ace 7402 levers won't index a 600 or Ultegra rear derailleur correctly (or the other way round) without an alternate cable routing.
- Campagnolo 8-speed Ergopower is built around Campagnolo's 5.0 mm cog spacing, not Shimano's 4.8 mm.
- Campagnolo's first indexed system, Syncro, had too little cable travel and too much cable tension to index reliably.
- SunTour's indexed shifters were designed around SunTour derailleurs and cogs, so treat any cross-brand indexed setup as unproven. Friction levers like the Nuovo Record avoid the question.
Before you bid
- Write down your frame's bottom bracket thread, shell width, rear spacing, seatpost size, seat tube diameter and headset thread.
- Ask the seller for the thread or size markings on cups, stems, bars and posts, and for the freewheel or freehub type and speed count.
- Match taper type (ISO or JIS) and work out derailleur capacity before you build a drivetrain from mixed brands.
For condition checks, see inspecting used vintage road components. To place a part in time, see dating vintage Campagnolo and Shimano components.
