{"id":3612,"date":"2026-04-03T08:57:28","date_gmt":"2026-04-03T08:57:28","guid":{"rendered":"https:\/\/motorcyclechain.top\/?p=3612"},"modified":"2026-04-03T08:57:28","modified_gmt":"2026-04-03T08:57:28","slug":"motorcycle-chain-sizes-explained","status":"publish","type":"post","link":"https:\/\/motorcyclechain.top\/pt\/motorcycle-chain-sizes-explained\/","title":{"rendered":"Motorcycle Chain Sizes Explained"},"content":{"rendered":"
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Motorcycle Chain Sizes Explained<\/h1>\n

The three-digit number on every chain’s outer plate encodes pitch and width. Both must match your sprockets exactly \u2014 one wrong digit means the chain won’t work. This guide decodes the numbering system and shows which size fits which machine.<\/p>\n

Find Your Chain Size<\/a><\/p>\n<\/div>\n<\/div>\n

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How to Read a Motorcycle Chain Size Number<\/h2>\n

Motorcycle chain sizes<\/strong> are encoded in a three-digit code stamped on the outer plate of every chain. The code is not arbitrary \u2014 the first one or two digits encode the pitch (the distance between adjacent pins), and the last two digits identify the inner width family. Under JIS B 1801, the standard governing all motorcycle chain dimensions in Japan and Korea, these two values completely define sprocket compatibility requirements.<\/p>\n<\/div>\n

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Decoding “428” and “520” \u2014 the two most common pitches<\/p>\n

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4<\/div>\n
Pitch = 4\/8 inch<\/div>\n
= 12.700 mm
\nApplies to: 415, 420, 428<\/div>\n<\/div>\n
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28<\/div>\n
Width code “28”<\/div>\n
Inner width = 7.85 mm
\nSpecific to 428 family<\/div>\n<\/div>\n
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5<\/div>\n
Pitch = 5\/8 inch<\/div>\n
= 15.875 mm
\nApplies to: 520, 525, 530<\/div>\n<\/div>\n
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20<\/div>\n
Width code “20”<\/div>\n
Inner width = 6.35 mm
\nSpecific to 520 family<\/div>\n<\/div>\n<\/div>\n

Note: width code numbers are identifiers \u2014 they do not convert directly to millimetres. Always verify against the published JIS B 1801 specification table.<\/p>\n<\/div>\n

The suffix letters after the base code identify the chain variant: no suffix = standard non-sealed; H = reinforced heavier plates; O = O-ring sealed; X = X-ring sealed; SX = Super X-ring sealed. So “525H-SX” is a 15.875 mm pitch, 7.94 mm inner width, H-grade reinforced Super X-ring sealed chain.<\/p>\n

The width code is not a decimal measurement. “20” does not mean 2.0 mm \u2014 it identifies the 6.35 mm inner width family of the 520 series. Always use the published specification table rather than deriving measurements from the code number.<\/p>\n

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The Five Main Motorcycle Chain Sizes in Detail<\/h2>\n

Two pitch families cover all five sizes: the 12.700 mm (1\/2-inch) family for smaller machines, and the 15.875 mm (5\/8-inch) family for mid-range and larger machines. Within each pitch family, inner width varies to match the torque capacity and sprocket geometry requirements of different engine classes.<\/p>\n

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420<\/div>\n

\"420<\/p>\n<\/div>\n

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420 \u2014 Lightest in the 1\/2-Inch Family<\/h3>\n

The 420’s 6.35 mm inner width makes it the narrowest of the 12.70 mm pitch family. At 0.57 kg\/m, a 100-link 420 chain weighs approximately 570 g \u2014 for a 65\u201380 kg scooter, this chain weight relative to the machine’s total mass is more significant than it would be on a 200 kg touring bike. Fitting a 428 where a 420 is specified would add 140 g of rotating mass for no measurable strength benefit at 50\u2013125cc power levels.<\/p>\n

Pitch:<\/strong> 12.700 mm<\/span>
\nInner width:<\/strong> 6.35 mm<\/span>
\nRoller \u00d8:<\/strong> 7.77 mm<\/span>
\nTensile:<\/strong> 15,6 kN<\/span>
\nWeight:<\/strong> 0.57 kg\/m<\/span>
\nTypical use:<\/strong> 50\u2013125cc scooters, mini bikes<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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428<\/div>\n

\"428<\/p>\n<\/div>\n

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428 \u2014 The Most Widely Used Worldwide<\/h3>\n

The 428 is the highest-volume single chain size in the global aftermarket. Sharing pitch with the 420, it adds inner width (7.85 vs 6.35 mm) and roller diameter (8.51 vs 7.77 mm), giving a larger tooth contact area. The standard 428 at 17.8 kN covers most 125\u2013250cc engines; the 428H at 20.6 kN handles the higher-output end without any sprocket change. Its versatility across dirt bikes, street bikes, scooters, dual-sports, and cruisers in the most populated displacement class makes replacement parts universally available.<\/p>\n

Pitch:<\/strong> 12.700 mm<\/span>
\nInner width:<\/strong> 7.85 mm<\/span>
\nRoller \u00d8:<\/strong> 8.51 mm<\/span>
\nTensile:<\/strong> 17,8 kN<\/span>
\nWeight:<\/strong> 0.71 kg\/m<\/span>
\nTypical use:<\/strong> 125\u2013250cc street, dirt, enduro<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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520<\/div>\n

\"520<\/p>\n<\/div>\n

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520 \u2014 Lightest in the 5\/8-Inch Family<\/h3>\n

The 520 moves to the 15.875 mm pitch family \u2014 longer pitch means larger roller contact radius at the sprocket tooth, distributing load over a greater arc. Its 6.35 mm inner width \u2014 the same as the 420 despite the longer pitch \u2014 makes it the narrowest and lightest of the three 5\/8-inch variants at 0.91 kg\/m. For sport bikes where minimising rotating mass matters, the 520 is the natural specification: a 520H-X at 34.0 kN gives sealed performance at a weight comparable to a standard 530.<\/p>\n

Pitch:<\/strong> 15,875 mm<\/span>
\nInner width:<\/strong> 6.35 mm<\/span>
\nRoller \u00d8:<\/strong> 10.14 mm<\/span>
\nTensile:<\/strong> 26,5 kN<\/span>
\nWeight:<\/strong> 0,91 kg\/m<\/span>
\nTypical use:<\/strong> 250\u2013600cc sport, naked, inline-4<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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525<\/div>\n

\"525<\/p>\n<\/div>\n

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525 \u2014 The Balance Point Between 520 and 530<\/h3>\n

The 525’s 7.94 mm inner width is 1.59 mm wider than the 520 and 1.59 mm narrower than the 530. That wider roller provides more tooth-face contact area than the 520 \u2014 distributing load across a broader band of the sprocket tooth at a given chain tension. The trade-off versus the 520 is modest: 0.98 vs 0.91 kg\/m, a difference of 70 g per metre. The 525 is typical OEM specification for adventure bikes, parallel-twin naked bikes, and sport tourers in the 650\u2013750cc class.<\/p>\n

Pitch:<\/strong> 15,875 mm<\/span>
\nInner width:<\/strong> 7.94 mm<\/span>
\nRoller \u00d8:<\/strong> 10.14 mm<\/span>
\nTensile:<\/strong> 26,5 kN<\/span>
\nWeight:<\/strong> 0.98 kg\/m<\/span>
\nTypical use:<\/strong> 400\u2013750cc adventure, naked twin<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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530<\/div>\n

\"530<\/p>\n<\/div>\n

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530 \u2014 Widest Standard, Highest Peak Strength<\/h3>\n

The 530’s 9.53 mm inner width makes the broadest tooth-face contact of the three 15.875 mm variants. At 1.09 kg\/m for the standard, it is the heaviest \u2014 but on a 250 kg touring machine this is not a meaningful consideration. The strength advantage of the 530 family appears clearly in the SX-grade: the 530-SX at 43,0 kN<\/strong> is the highest tensile strength in the Korea Ever-Power range. For a fully-loaded touring motorcycle where combined mass exceeds 450 kg, the 530-SX’s structural margin over the working load is both technically sound and practically reassuring.<\/p>\n

Pitch:<\/strong> 15,875 mm<\/span>
\nInner width:<\/strong> 9.53 mm<\/span>
\nRoller \u00d8:<\/strong> 10.14 mm<\/span>
\nTensile:<\/strong> 26.5 kN (530-SX: 43.0 kN)<\/span>
\nWeight:<\/strong> 1.09 kg\/m<\/span>
\nTypical use:<\/strong> 600cc+ cruiser, tourer, large naked<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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All Five Sizes \u2014 Complete Specification Table<\/h2>\n
\n\n\n\n\n\n\n\n\n\n
Tamanho<\/th>\nPasso (mm)<\/th>\nLargura interna (mm)<\/th>\nRoller \u00d8 (mm)<\/th>\nStandard Tensile<\/th>\nTop SX Tensile<\/th>\nPeso (kg\/m)<\/th>\nEngine Class<\/th>\n<\/tr>\n<\/thead>\n
420<\/td>\n12.700<\/td>\n6.35<\/td>\n7.77<\/td>\n15,6 kN<\/td>\n\u2014<\/td>\n0.57<\/td>\n50\u2013125cc scooter, mini bike<\/td>\n<\/tr>\n
428<\/td>\n12.700<\/td>\n7.85<\/td>\n8.51<\/td>\n17,8 kN<\/td>\n28.0 kN (SX)<\/td>\n0.71<\/td>\n125\u2013250cc street, dirt, enduro<\/td>\n<\/tr>\n
520<\/td>\n15.875<\/td>\n6.35<\/td>\n10.14<\/td>\n26,5 kN<\/td>\n36.0 kN (SX3)<\/td>\n0.91<\/td>\n250\u2013600cc sport, naked, MX<\/td>\n<\/tr>\n
525<\/td>\n15.875<\/td>\n7.94<\/td>\n10.14<\/td>\n26,5 kN<\/td>\n40.0 kN (525-SX)<\/td>\n0.98<\/td>\n400\u2013750cc adventure, naked twin<\/td>\n<\/tr>\n
530<\/td>\n15.875<\/td>\n9.53<\/td>\n10.14<\/td>\n26,5 kN<\/td>\n43.0 kN (530-SX)<\/td>\n1.09<\/td>\n600cc+ touring, cruiser, large naked<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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What You Can and Cannot Mix<\/h2>\n

Pitch determines sprocket tooth spacing \u2014 the 12.70 mm pitch chains (420, 428) will not engage correctly on 15.875 mm pitch sprockets, and vice versa. Within the same pitch family, inner width also must match the sprocket tooth gap. A 520 roller (6.35 mm wide) will not seat correctly in sprocket grooves designed for a 530 roller (9.53 mm wide) \u2014 the narrower roller sits between the tooth faces rather than against them, causing immediate abnormal wear.<\/p>\n

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\u2713 Change without new sprockets<\/h3>\n