Motorcycle Chain Loose Symptoms and Solutions

The most typical signal of a loose chain is usually a loud “bang” sound, or the sound of a metal flapping back rocker (Swingarm), especially at low speeds. What follows is often the uncomfortable feeling of frustration when you give or receive oil, and even shifting gears becomes jerky and sloppiness.

If you look at it with the naked eye, you will find that the chain is hanging down so much that it can sometimes even touch the exhaust pipe or the big brace. If you start to pull the chain on the back tooth plate, you can even pull the chain directly to expose the tip of the tooth inside. If your car has any 1 of the above situations, to be honest, its current operating state is beyond the safety range.

But don’t panic. After so many years of repairing cars, I have seen too many such situations. Sometimes it only takes 10 minutes to tighten up. But I also have to put the ugly words in front—sometimes, this is the precursor to changing the chain. Next, I will show you how to quickly do a “physical examination” of your car in 30 seconds using only your eyes, ears and hands.

The Sound Check

When the chain is loose, it flings like an uncontrolled metal whip. The most obvious symptom is the so-called “chain slap” (Chain Slap).

What do you want to listen for: When you are riding at low speed, rolling your car to stop, or crossing a speed bump, listen carefully for the “click” or clap of metal impact.
What’s going on: The chain slack is so big that it physically hits your back arm or the plastic chain guard.
Novice trap: a lot of people will think, “hey, I ride fast sound is gone, is it okay?” Don’t be fooled. As the speed comes up, the centrifugal force will force the chain to straighten, and the noise will naturally disappear. The problem has not been solved. The pulling force only temporarily covers up the hidden danger, but may be brewing a bigger failure.

The “Feel” Test

If you can’t hear clearly in your full helmet, your right hand (throttle hand) will tell you the truth. In my opinion, the chain is the bridge between the engine and the wheel. If the bridge is loose, how can traffic be smooth?

“Lag and Slam” (Lag and Slam): When you twist the throttle, do you feel an extremely short delay, followed by a violent “crash” or “forward jump”? This is the engine in the real drive wheels before the first, have to consume the chain of those excessive empty position.
Slow down and rush: the reverse is also true. When you quickly collect the oil and slow down, does the car feel rushing and rushing, like “booing”? This kind of rush of the transmission system (Driveline lash) is a classic symptom of loose chain.
Technician’s warning: listen to my 1 advice, if this feeling of frustration is accompanied by a loud “click” sound, or if you feel that the chain has slipped on the gear (jumping teeth), pull over immediately and stop riding. You may be a few minutes away from the chain falling off, which is no joke.

The Visual “Pull Test” (No Tools Required)

You don’t need a micrometer to know if you’re in a danger zone. Stop the car (with big support and big support, no big support and side ladder) and squat down to look at the back tooth plate.

Diagnosis key: find the rear end of the disc (that is, the 3 o’clock direction). Hold the 1 link chain with your fingers and try to pull it back away from the tray.
Criteria: If it is a healthy chain, you can hardly pull it. But if you can pull it apart and even see half or more of the tooth tips of the tray sticking out, then your chain is not just “loose”—it is “stretched” and completely worn out. This kind of situation, how tight all useless, directly replace it.

Measuring Correctly

Step 1: Find the “Tight Point”

Many riders do not know this detail: the wear of the chain is always uneven. Put the frame up and turn the rear wheel. You will find that the chain is loose in some positions and tight in some positions. Be sure to adjust based on the tightest point. If you adjust it at the loosest point, when the wheel turns to the tightest point, the chain will be too tight, either breaking the chain or directly destroying your countershaft bearing (Countershaft bearing).

Step 2: Measure

Move the lower half of the chain up and down to measure the total distance from the lowest point to the highest point.
Street car: usually requires a swing amplitude of 25mm – 35mm mm (1.0 – 1.4 inches).
Off-road/ADV models: Because of the long suspension stroke, it usually needs to be looser, about 35mm-50mm.
Note: The specific value is always subject to the sticker on your owner’s manual or rear rocker arm.

Adjustment vs. Replacement

Look at your chain adjusters (those bolts or scale blocks near the rear axle).
If the rear axle has been moved to the end of the adjustment slot of the rear rocker arm;
Or the scale of the regulator has reached the “red zone” and exceeded the last scale line;
This means that the pin shaft inside the chain has worn too much, causing the chain to become longer in physical size than when it was new. It is very dangerous to force the tightening at this time. Don’t save this money, it’s time to buy a new set of chain teeth set.

About the Author
“I’m Mechanic Matt, a repair shop owner and avid rider with over 14 years of wrenching experience. I have seen every breakdown imaginable, so I write these guides to help you diagnose problems early, save money on repairs, and keep your rubber side down.”