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Bicycle chain

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  • #31
    Sorry error on my part. It seems MOST bicycle chains are a variation of #40. There have however been other pitches introduced from time to time.

    Here's a quote from Wikipedia:
    The chain in use on modern bicycles has a 1⁄2 inch (12.7 mm) pitch, which is the distance from one pin center to another, ANSI standard #40, where the 4 in "#40" indicates the pitch of the chain in eighths of an inch; and ISO standard 606 (metric) #8, where the 8 indicates the pitch in sixteenths of an inch. Its roller diameter is 5⁄16 inch (7.9 mm).

    1976: Shimano briefly made their own 10 pitch Dura-Ace track-specific system with 10 mm (3⁄8 in) (approximately) pitch from about 1976[13] to 1980[14]—called Shimano Dura-Ace 10 pitch. The Shimano 10 pitch system is incompatible with ANSI standard #40 (1/2") e.g. chains, sprockets and so on,[15][16] and was outlawed by the Japan Keirin Association, helping in its demise.[13]

    Chains come in 3⁄32 in (2.4 mm), 1⁄8 in (3.2 mm), 5⁄32 in (4.0 mm), or 3⁄16 in (4.8 mm) roller widths, the internal width between the inner plates. 1⁄8 in (3.2 mm) chains are typically used on bikes with a single rear sprocket: those with coaster brakes, hub gears, fixed gears such as track bicycles, or BMX bikes. Chains with 3⁄32 in (2.4 mm) wide rollers are generally used on bikes with derailleurs such as racing, touring, and mountain bikes.[17] Fixed sprockets and freewheels are also available in 3⁄32 in (2.4 mm) widths so fixed-gear and single-speed bikes can be set up to use the narrower and lighter 3⁄32 in (2.4 mm) chains. Finally, chains with 5⁄32 in (4.0 mm) wide rollers are used on cargo bikes and tricycles.

    With derailleur equipped bicycles, the external width of the chain (measured at the connecting rivet) also matters, because chains must not be too wide for the cogset or they will rub on the next larger sprocket, or too narrow that they might fall between two sprockets. Chains can also be identified by the number of rear sprockets they can support, anywhere from 3 to 13, and the list below enables measuring a chain of unknown origin to determine its suitability.
    • 6 speed – 7.3 mm (932 in) (Shimano HG), 7.1 mm (932 in) (SRAM, Shimano IG)
    • 7 speed – 7.3 mm (9⁄32 in) (Shimano HG), 7.1 mm (9⁄32 in) (SRAM, Shimano IG)
    • 8 speed – 7.3 mm (9⁄32 in) (Shimano HG), 7.1 mm (9⁄32 in) (SRAM, Shimano IG)
    • 9 speed – 6.5 to 7.0 mm (1⁄4 to 9⁄32 in) (all brands)
    • 10 speed – 6.0 to 7.0 mm (1⁄4 to 9⁄32 in) (Shimano, Campagnolo)
    • 10 speed (Narrow) – 5.88 mm (7⁄32 in) (Campagnolo, KMC)
    • 10 speed (Narrow, Direction) – 5.88 mm (7⁄32 in) (Shimano CN-5700, CN-6700, CN-7900)
    • 11 speed – 5.5 to 5.62 mm (7⁄32 to 7⁄32 in) (Campagnolo, KMC, Shimano CN-9000)
    • 12 speed - 5.3 mm (13⁄64 in) (SRAM)
    • 13 speed - 4.9mm wide - Campagnolo Ekar[18]

    The Wikibook, "Bicycle Maintenance and Repair", has more details on this topic.
    Last edited by projectnut; 06-19-2022, 09:42 AM.