EK Z3D RIVET MASTER LINK 520

This is the genuine EK rivet connecting link (MLJ) for the 520 Z3D ThreeD chain, supplied with its seals and grease and available in a choice of finishes. It looks like a simple part, and it is. The difficulty isn’t fitting it, it’s buying the correct one, because 520 is the size where more links get ordered wrong than any other.

Why 520 Is the Easiest Size to Get Wrong

EK produces more chain series in 520 than in any other size. The ThreeD Z3D, the ZVX3, the SRX2, the RV3D, the MVXZ2 and others all exist in 520, and every one of them uses its own connecting link.

They are not interchangeable. The plate thickness, pin length, and seal profile are specific to each series. A 520 ZVX3 link will not do the job on a 520 Z3D chain even though both are 520, both are EK, and both look similar in a photograph.

There’s a second trap. Some of those series offer clip-type or screw-type links as alternatives to riveting. The Z3D does not. If you’ve previously owned a chain where a clip link was an option, don’t assume the same applies here.

So before ordering, identify the series, not just the size.

Identify Your Chain in 60 Seconds

Look at the side plates. EK stamps the chain designation onto the plates. On a Z3D chain you’ll find ThreeD or 520Z markings. Clean a section with a rag first, since grime hides the stamp.

Check the shape of the plates. The Z3D has a distinctive three-dimensional curved outer plate with a dimple, not a flat plate. If your chain’s outer plates are flat, it isn’t a Z3D.

Find the box. If you still have the packaging, the ThreeD box and the part number on it settle the question instantly.

Check your purchase record. The invoice or order confirmation from when the chain was bought will name the series.

Still unsure? Send us a clear, close-up photo of a clean section of your chain’s side plates and we’ll identify it for you before you order. That takes two minutes and saves a wrong purchase.

What’s in the Package

The connecting link. One inner link section with two hollow-tipped pins, plus the separate outer plate that gets pressed and riveted on.

Four O-ring seals. Two per pin. They sit between the inner and outer plates and hold the lubricant around the pin. Without them in the right place, the joint is unsealed and the grease escapes on the first ride.

A grease sachet. This is the lubricant that lives inside the sealed joint for the life of the link. It is applied during assembly, not afterwards, and there’s no way to add it later once the link is riveted.

Everything in the package is needed. If a seal is missing or a pin has been dropped and lost, buy a new link rather than improvising.

One Use Only

A rivet link is fitted once. The riveting process permanently spreads the hollow pin tips to lock the outer plate in place, and that deformation cannot be undone and redone safely. If a chain has been removed, the link that came off goes in the bin, not back on the bike.

The same applies to the seals. Compressed seals don’t recover, and re-used seals leak.

Fitting It, Step by Step

You need a chain riveting tool. There is no clip or screw version of this link, so there’s no way around the tool. If you don’t have one, this is a workshop job.

1. Clean the chain ends. Both ends of the chain should be clean where the link goes in. Grit trapped in the joint defeats the seals immediately.
2. Grease the pins and seals. Open the sachet and coat the pins and all four seals before you assemble anything.
3. Fit two seals onto the inner link. One over each pin, seated flat against the inner plate.
4. Push the pins through both chain ends. The inner link joins the two ends of the chain together.
5. Fit the remaining two seals. One over each pin on the outside, before the outer plate goes on.
6. Press the outer plate on with the tool. Press it until the link is the same width as the chain’s other links. Compare against a neighbouring link rather than guessing. Pressing too far binds the joint.
7. Rivet both pin ends. The tool spreads the hollow tips to lock the plate. Work both pins evenly and check your tool’s instructions for the correct flare.
8. Test the movement. The finished link must flex as freely as every other link. Any stiffness means it’s over-pressed and must be corrected, because a stiff link creates a tight spot that wears the chain unevenly.

Common Mistakes

Ordering by size alone. “520” is not enough. The series matters just as much.

Skipping the grease. The sachet is not an optional extra. The joint is sealed for life, so this is your only chance to lubricate it.

Seals in the wrong position. Four seals, two per pin, between the plates. Getting the order wrong leaves the joint unsealed.

Over-pressing the outer plate. The most common cause of a stiff link. Measure against the chain.

Riveting unevenly. Both pins need the same treatment. One under-riveted pin is a failure waiting to happen.

Reusing the old link. The single biggest mistake, and the most dangerous.

Order Yours

The right link, matched to your exact chain. Order now with fast delivery across Saudi Arabia and all Gulf countries. Send us a photo of your chain’s side plates if you’d like us to confirm the series before you buy.