A motorcycle chain comprises two precision ground pins peened at each end as a rivet, two bushes, two rollers and two side plates. A further pair of outer side plates join each link to the next link. In O ring chain a round seal is fitted on the pin between the plates to retain lubricant. The seal is contoured for less drag in X ring chains.
The Number of links is measured by the number of pitches, which is the gap between each pin or rivet and includes a Spring/clip or Rivet link to give an even number.
Please note that we supply lengths of chain to fit standard sprockets. When using sprockets with 2 or more extra teeth a chain with more links is often needed. Feel free to call for any assistance.

Metric Dimensions

Chain Pitch Width Roller Diameter
415 12.70mm 4.88mm 7.75mm
420 12.70mm 6.35mm 7.75mm
428 12.70mm 7.75mm 8.51mm
520 15.88mm 6.35mm 10.16mm
525 15.88mm 7.85mm 10.16mm
530 15.88mm 9.53mm 10.16mm
532 15.88mm 9.53mm 11.10mm
630 19.05mm 9.53mm 11.91mm
632 19.05mm 9.66mm 12.68mm

Side plate thickness varies with grade and make of chain. As a rule, 1.5 to 2.6 mm. It is important for safety to join chain with the manufacturers correct Rivet Soft Link or Split Spring Link.
Size, Manufacturer, and grade are often stamped on some of the side plates.

British Classic Chain Sizes and Modern Equivalents

Classic Size Reynolds No Equivalent
1/2 x 3/16 Inch 110044 Similar Modern 420 - See Below
1/2 x 5/16 Inch 110046 Modern 428
5/8 x 1/4 Inch 110054 Modern 520
5/8 x 3/8 Inch 110056 Modern 530

BSA/Triumph Bantam/Cub and similar earlier lightweight British motorcycles need a Original 1/2 X 3/16 inch chain. This is because metric equivalents, although having the same pitch has different size rollers which will not correctly seat into the sprockets and will very quickly knock the tops off the sprocket teeth.
Many British bikes do not have sufficient clearance to fit Modern heavy-duty chains which tend to have very wide side plates.
Some British Classic bike run chains with an odd number of links. This is made possible by a special half link.

What's the Difference Between 50 and 530 Chains?

Nowadays there is little to no difference between 50 and 530 chains, but the difference originated from where 50 chains were used in industrial applications whereas 530 chains were used primarily for transport and vehicles. Therefore 50 chains were traditionally more durable but heavier and more expensive. To avoid confusion many chains these days are in fact marked as 50 (530) chains.

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