Sprockets and segments are small components with a big impact. Essential parts of any tracked machine’s undercarriage, they work hand-in-hand with the track chain to drive movement, transfer power, and keep your machine operating reliably. When sprockets wear out, everything from track tension to fuel efficiency is affected — and ignoring the early signs often leads to costly downtime.
This guide covers everything you need to know about sprockets and segments: what they do, why they matter, and how to know when it’s time to replace them.
What Are Sprockets and Segments?
Sprockets
Sprockets are toothed, circular components mounted to the final drive of a tracked machine. Their job is simple but critical:
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Transfer engine power to the track chain
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Propel the machine forward or backward
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Keep the tracks correctly aligned and tensioned
A sprocket’s teeth engage directly with the track links, meaning even minor wear can quickly affect overall undercarriage performance.
Segments
Segments serve the same purpose but come in multiple pieces instead of one solid sprocket ring.
They are commonly used on larger crawler dozers and excavators.
Benefits include:
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Easy replacement (single worn segments can be swapped)
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Reduced downtime
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Lower maintenance costs
Both sprockets and segments must mesh perfectly with the track chain, making compatibility and quality essential.
Why Sprockets Are So Important
A worn sprocket affects more than just smooth machine movement. Poor engagement leads to:
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Accelerated track wear
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Increased vibration and noise
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Higher fuel consumption
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Loss of traction
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Premature failure of rollers, idlers, and final drives
Choosing high-quality sprockets or segments — like MST’s ITR® range — helps preserve machine health and reduce long-term operating costs.
How Sprockets Wear Over Time
Sprocket wear is caused by the constant friction between the sprocket teeth and the track links.
Common wear factors include:
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Abrasive ground conditions (sand, gravel, clay)
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Misaligned or over-tight tracks
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Poor-quality track links
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High-impact applications
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Running the machine in reverse frequently
As the teeth wear down, their shape changes, which accelerates wear on the track chain, creating a cycle that only worsens with time.
Signs Your Sprockets or Segments Need Replacing
Catch the signs early and you’ll avoid unnecessary undercarriage damage. Look for:
1. Hooked or Sharp Teeth
The most common indicator.
Teeth should be symmetrical — hooked teeth mean they’re worn down and no longer seating properly with the track links.
2. Visible Wear Patterns
Flattened tips, cupped tooth faces, or uneven wear are all red flags.
3. Excessive Track Noise or Vibration
If the machine feels rougher than usual, the sprocket may not be engaging correctly.
4. Track Skipping or Jumping
A worn sprocket can cause the track to slip or skip under load — a serious sign it needs replacing immediately.
5. Poor Track Alignment
If the tracks are pulling to one side, the sprocket may be worn unevenly or out of sync with the chain.
6. Accelerated Wear on the Track Chain
If you’re replacing track links more frequently, the sprocket may be the root cause.
How Often Should Sprockets Be Replaced?
There’s no universal answer — it depends heavily on:
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Hours of use
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Ground conditions
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Track maintenance
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Machine size and workload
However, a general rule of thumb is:
Replace sprockets whenever you install a new track chain.
A worn sprocket paired with a new chain will cause rapid wear to the chain, shortening its life dramatically.
Sprockets vs Segments: Which Is Better?
Both perform the same function, but they fit different machine types:
| Component | Typical Machines | Advantages |
|---|---|---|
| Sprockets (single-piece) | Mini excavators, compact track loaders | Strong, simple, durable |
| Segments (multi-piece) | Dozers, large excavators | Easier & cheaper to replace, less downtime |
MST supplies both, covering everything from mini excavators to heavy mining equipment.
How to Extend Sprocket Life
A few simple maintenance habits can significantly extend the life of your sprockets:
✔ Keep track tension correct
Tight tracks increase sprocket stress. Loose tracks increase tooth wear.
✔ Clean the undercarriage daily
Mud and stones act like sandpaper.
✔ Rotate or replace worn components early
Treat the undercarriage as a system — one worn part affects the rest.
✔ Use high-quality track chains
Poor-quality chains wear sprockets prematurely.
✔ Avoid excessive reversing
Driving in reverse accelerates wear on sprocket teeth.
With a solid maintenance routine, sprockets and track chains will last significantly longer.
High-Quality Sprockets and Segments from MST
MST supplies the UK’s largest range of ITR® undercarriage components, including:
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Sprockets & Segments
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Track Chains
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Rollers, Idlers & Track Adjusters
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Complete Track Groups
With over 50 years of undercarriage expertise, our team can recommend the correct sprocket or segment for your machine, site conditions, and operating environment.
Need Replacement Sprockets or Undercarriage Advice?
MST stocks sprockets and segments for most major brands including Caterpillar®, Komatsu®, JCB®, Volvo®, Hitachi® and more.
Contact our team today for expert advice and rapid delivery across the UK.