I’ve had my chain come off more than once. It’s not a regular occurrence. But when it does happen, it’s ruined my ride every time. It’s important to carry the right tools to make on-the-spot repairs. More on tools later.. This guide will take you through the exact process of how to tighten a dirt bike chain the right way.
How To Tell If Your Dirt Bike Chain Is Too Loose
The most obvious side-effect of your chain being too loose is that it can slip off while you’re riding. This can cause damage to the rubber on the swingarm and destroy the teeth on the sprockets. A loose chain can “stretch” out, reducing its durability and lifespan. In addition, the rollers and pins will begin to degrade. Once these are damaged you will need to replace them entirely.
Does A Chain Stretch?
I say “stretch”, because contrary to popular belief, chains do not stretch. Your bike’s engine does not cause the chain to stretch. A chain is comprised of a few core components. Link plates, pins, bushings, and rollers. “Chain stretch” is actually wearing in the form of increasing space between chain links as the pins and mating holes increase. Each link of a chain is given a limit to the amount of wear it can accumulate. This limit is stipulated by the manufacturer and is usually around 0.006″ per link. If you multiply that by the number of links in the chain (usually about 100-120 links) you end up with 0.6 inches of “stretch” or wear.
What Happens If The Chain Is Too Loose?
A dirt bike chain that is too loose is very likely to slip off the sprocket. When the chain slips off the sprocket, it doesn’t just keep spinning wildly. One of two things will take place. Either the chain will get stuck in the chain guard where it will continue to grind away until the wheels stop spinning. Or, the chain will bunch up, spinning up into the countershaft sprocket causing complete seizure. With so much rotating mass, and nowhere for all this rotating mass to go, the crankcase is likely to crack and destroy the transmission in the process. The tranny allows the dirt bike engine to spin freely of the wheels while idling as well as ensures the engine speed is running at the right range relative to the speed of the dirt bike.
Can you see how a loos chain could cause some serious problems?
What Happens If The Chain Is Too Tight?
If the chain on your dirt bike is too tight it can put immense pressure on the working parts of the engine and affect the suspension. The sprocket teeth will wear much faster as the engine is overworked. A chain that is too tight could snap and break when placed under enough force.
How To Check If Your Chain Is Too Loose or Too Tight
It’s critical that the tension on your chain is set correctly. Too loose or too tight could cause serious problems. Here are some simple steps to ensure your chain is set up properly.
How To Adjust A Dirt Bike Chain
Adjusting the tension on your chain is one of the more simple maintenance tasks, although it is often overlooked. There are a few tools you might need. But before you get to adjust your chain, you must give it a thorough wash. If your chain is caked with dirt, oil, grime, and all the other nasty sh*t, adjustment of the chain is going to be a seriously messy job. If your chain is in that kind of condition, it’s no wonder why you’re busy reading this guide. Cleaning your chain is a vital maintenance task that should be done after every ride.
Not all of these tools are essential, but they do make the job easier.
Steps To Adjusting a Dirt Bike Chain
These are the step by step instructions on how to tighten your dirt bike chain.
- On the rear wheel, loosen the axle nut just enough so that it is semi-tight.
- Locate the chain adjuster bolts and pay careful attention to the lines/thread as you will use these lines for reference when tightening or loosening the chain.
- If your chain is too tight, loosen both chain adjuster bolts equally.
- If your chain is too loose, tighten both chain adjuster bolts equally.
- The chain should loosen or tighten depending on which way you turn the bolts
- As described earlier, pull up on the chain until the distance between the chain and the chain guard is correct according to your owner’s manual – or follow the three-finger estimate rule (35-50mm).
- Tighten the axle nut back into place and you’re all set.
How Long Does a Dirt Bike Chain Last?
One cannot simply say that a chain will last X miles. Each chain manufacturer is different. You also get different types of chains – X-ring, O-ring, Z-ring. The degrading of a chain also depends on the type of riding and the terrain. Sand and mud will cause I chain to degrade much faster than street riding. Read our guide on how long a chain will last.
You can visually inspect the condition of the chain by placing your bike up on a stand and rotating the rear wheel. You want to pay attention to how the chain feels as it rotates. There could be links that have become rigid and stick together causing tight spots in the chain.
Grab the chain at the furthest point along the rear sprocket. Try to pull the chain off the sprocket. If it raises by more than the length of a sprocket tooth, you should replace the chain. Try to push and pull the chain from side to side on top of the sprocket, the chain has worn out and needs to be replaced.
What Else To Replace When Replacing The Chain
Whenever you replace your chain it’s a good idea to take note of the condition of the surrounding mechanical parts. Take a look at the chain slider, chain guide, guard, rollers, and most importantly, the sprocket. Riding your bike with a new chain and old sprocket can cause the new chain to degrade rapidly.
You can visually inspect the condition of your sprocket by observing the teeth. Over time, the engine and chain will cause the teeth on a sprocket to curve. If a sprocket is badly worn, the teeth can even shorten and become round.
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