Picture of Rieju Marathon Pro 125 12 Chain DID Heavy Duty

Part Description

Rieju Marathon Pro 125 12 Chain DID Heavy Duty

Supplied with one spring link. More spring links, and rivet links, are available.

DID Logo

DID 428 HD Heavy Duty Chain

As well as using solid bushing, which can last 1.2 to 4 times as long as chains without, DID's HD Heavy Duty chain features thicker plates than the standard chain, and its tensile strength is roughly 20% higher. As with all DID chains, it is made with the latest chain manufacturing technology by DID's experienced engineers in Japan, at the high quality DID is so renowned for.

Pin Length Roller Diameter Plate Thickness Weight Tensile Strength Colour
18.90mm 8.50mm 2.0mm 1.00kg per 100 links 23.4KN Plain

If the original equipment chain was an O-Ring or X-Ring chain, it must be replaced with a sealed chain of equal or greater strength.

For more information about transmission chains, take a look at our Chain Maintenance Guide or our Chain Dimensions Guide

Related Products

Chain Adjusters

Chain Lube

Chain Tools

Delivery and Returns

We want you to be happy with your purchase. If you're not, just return the products to our warehouse. Unless faulty, we'd like this to be within 30 days of purchase. Exceptions apply to certain products.

Read our full returns policies


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.

... Read more » Chain Dimensions

Replacing The Drive Chain

The chain will naturally stretch as it wears. On a non-sealed chain this should not exceed 3% of its original length. Sealed chain stretch should not exceed 1% of its original length. If the stretch exceeds this it needs to be replaced.

Tension Adjustment

A drive chain that carries too much tensions speeds up wear by excessive amounts of pressure being placed on the sprocket teeth, chain joints and the gearbox main-shaft bearings. One that is too loose is at risk of a whip action that may cause it to snap. Having an incorrect tension can also cause the chain to stretch.

Normal sag is 3/4"; to check, press down on the top strand of the drive chain with your fingers. Tighten or loosen to achieve the desired sag. Note this should be performed with the weight of the rider on the bike. It is advised to check your manufacturer's handbook for your particular machine.

Sprocket alignment

Misaligned sprockets can greatly reduce chain and sprocket life. Check sprocket alignment periodically to ensure they are straight.

... Read more » Chain Maintenance

Instructional DVD- A Guide For Replacing Your Chain and Sprockets

The complete guide to checking, removing, replacing and maintaining your chain and sprockets. Professionally filmed in our studio, Nick Hine shows you exactly how to do each job - with clear, close-up shots, tips, advice and techniques that enable you to get a professional finish - even if you have no experience.

All DVDs start and end with the bike on the ground, They don't miss out any steps and always use standard home garage tools where possible and show you how to make your own special tools where necessary. We explain why you need to do each task and try to give you a good understanding of the principles behind each job.

  • Check and assess your chain and sprockets for wear
  • Safely jack and support your bike
  • Correctly remove different types of chain
  • Replace each component independently
  • Fit your new split link correctly
  • Adjust and maintain your new chain
Swift Chain
Motorcycle Drive Chain
Swift SX-Ring Chains

Cutting edge design, specially heat treated materials and competitive pricing is the winning combination for the increasingly popular Swift Chain.

Swift Chain is produced in Taiwan by the same manufacturers that make original-equipment chain. High quality specially heat treated steel is used to make each chain, resulting in an exceptional tensile strength.

The Swift range includes Standard, Heavy Duty, Heavy Duty O-Ring and Heavy Duty X-Ring chains; listed to over 10,000 different models and available in a variety of pitches and cut lengths.

Swift chains can also be purchased as part of a kit to include JT front and rear sprockets.

The full specifications for Swift Chain can be found on the Swift website.

Swift Chain Group


Supplying quality after market motorcycle parts direct to the trade