How To Check Motorcycle Chain Wear

To check motorcycle chain wear, first lay the big ladder or side ladder of the car and put it in neutral. Squat down on the back tray, find the rearmost position (that is, 3 o’clock), and try to pull the chain back.

If you can easily pull the chain away from the tooth plate and expose half of the teeth or more, then the chain is basically useless and you have to replace it with the tooth plate. A healthy chain should cling to the tooth plate with almost no gap.

This simple test, which requires no tools, is your most important first checkpoint. It can tell you immediately whether the chain has “stretched” to the edge of danger—this situation means that the internal pins and rollers have worn out, resulting in a larger spacing between each.

This video demonstrates how to check for chain wear:

Understanding The Pull Test

This trick is commonly known as “pull test” in our maintenance circles. Although some complicated methods are to use vernier calipers to measure the length of a specific section, this is the most efficient “field” method to judge whether the chain is dead or not when actually repairing cars or running mountains.

This test works because it isolates the tension of the chain and directly tests the bite of the chain and the teeth of the back tooth plate. The pitch of the new chain (Pitch, the distance between two segments) and the tooth pitch of the cone are perfectly matched. As the chain wears, the pitch becomes longer. If you pull hard at the end, you will physically test whether this “matching degree” is still there.

Detailed Explanation Of Inspection Steps

Step 1: Preparatory Work: Side Ladder And Neutral Gear

The neutral gear must be engaged. If you are in gear, the tension from the gearbox will limit the movement of the chain, and you will not feel that kind of openness when pulling, resulting in misjudgment that the chain is still very tight. Side ladders provide a stable base for you to safely squat over the rear wheels and look closely.

Step 2: Find The “3 O’Clock” Position

The test point must be the very end of the posterior tray (at 3 o’clock). This is the point farthest from the anterior dental tray. It is only in this position that the chain is completely wrapped around the teeth and is not affected by the direct pulling force caused by the geometry of the rear rocker arm. Don’t drag above or below, that’s not allowed.

Step 3: Action: Pull Straight Back

Hold the link chain in that position and pull it directly away from the center of the axle. Don’t use the strength of sucking. If there is a gap, pull it with a little force and it will show its original shape.

How To Read That Gap: Safety Vs Danger

The feeling on the hand and the feedback seen by the eyes are the most direct binary diagnosis:

• Health chain (safety): When you pull the chain, it should not move, or move very little. It should be deeply stuck in the base of the dental tray teeth. This means that the internal components of the chain are still tight and the pitch has not changed significantly.
• The “half-tooth” rule (danger): If you can see light through the middle of the chain and the tooth plate, or more specifically, half the height of the tooth or more, then the chain is dead. At this stage, the chain has been unable to bite all the teeth at the same time to evenly share the tension. On the contrary, the torque of the engine is fully pressed on the last teeth before the chain leaves the chainset. This leads to a sharp increase in the risk of breaking the chain or skipping teeth (off-chain) during the ride.

The Mechanical Principle Of The So-Called “Elongation”

We need to find out a concept, what is often said about the “elongation” of the chain. The metal side panel is not a rubber band, it will not really be stretched.

In fact, the “elongation” is the result of the loss of metal wear between the pin and the roller inside the chain. There is constant friction between the pin and the casing. Over time, the metal is worn away, the pin becomes thinner, and the hole in the roller becomes larger. Each section produces a micron-scale “Slop.” When you add up the tiny amount of more than one hundred chains, the total length of the whole chain increases significantly. You can pull the chain away from the tooth plate when you are doing the test, precisely because it is empty.

Why Must It Be Replaced

If your test results show a “half tooth gap”, don’t expect to adjust the adjustment screw on the rear rocker arm to solve the problem. The regulator can only eliminate the slack of the overhang, it cannot repair the already long pitch.

The chain and the tooth plate must be changed together. This is not negotiable in the rules of the trade, for 2 reasons:

• Safety: The elongated chain structure is fragile and may break at any time.
• Economic account: A worn chain must have worn your old tooth plate teeth into a hook shape. If you save money only to change the chain and install the new chain on the old tooth plate, the mismatch in pitch will ruin your new chain in less than 500 miles.

Author: Jake Reynolds

With over 14 years of experience turning wrenches on bikes, I believe safety starts with the drivetrain. I specialize in teaching riders practical, tool-free diagnostics to catch issues like chain stretch before they become dangerous failures.