What Are Excavator Tracks and How Do They Impact Performance?

Excavator tracks are the two continuous belts, rubber or steel, that carry the machine's weight, convert motor torque into travel and decide how much of the machine's rated performance ever reaches the ground. They are also the component most often blamed for faults that started somewhere else: a track that slaps, wanders or keeps riding up the sprocket is usually reporting a tension, fitment or undercarriage condition rather than a defect in the belt itself - the same reason a track comes off during use.

Last updated: October 5, 2026

This page covers what the two track types do differently, where a track decision shows up in fuel, ground damage and cycle time, how to tell a track fault from an undercarriage fault, and what to have in writing before you order.

What excavator tracks are actually doing

An excavator track is a continuous belt - rubber with embedded steel cords, or linked steel plates - running around a drive sprocket, a front idler and a set of rollers. Its three jobs are traction, flotation and stability: it spreads the machine's weight across a long contact patch and holds that contact while the machine digs, lifts and turns. Choosing the right type of track affects excavator durability, ground protection, operator comfort and operating costs, which is why the rubber-or-steel decision is worth making deliberately rather than by habit.

The two types are engineered for different work. Rubber tracks are flexible and comparatively light, made with reinforced rubber and embedded steel cords, and suited to sensitive surfaces and urban work because they cause minimal ground damage and run quietly - which is also why rubber tracks suit noise-sensitive sites. Steel tracks are heavy-duty linked steel plates with superior traction and durability in rough, abrasive or off-road conditions, at the cost of damage to soft surfaces and noticeably more vibration.

Feature	Rubber tracks	Steel tracks
Weight	Lighter, lower ground pressure	Heavier, contributes stability
Noise and vibration	Quieter, reduces operator fatigue	Louder, transmits more vibration
Surface impact	Minimal, protects pavement and turf	Can scar and compact soil
Durability	Less resistant to sharp debris	Highly durable on rough terrain
Traction	Good on firm, smooth surfaces	Superior on loose, muddy or uneven ground
Maintenance	Easier and less costly	Requires more frequent checks and repairs

Rubber tracks excel in landscaping, urban construction and indoor tasks; steel tracks dominate demolition, forestry and extremely rugged ground. Neither is a compromise for the other's work, and the decision is usually settled by what the machine has to cross, not by what it has to dig.

Where a track choice shows up in performance

Track specification and condition reach four things owners watch: fuel, ground restoration, downtime and operator hours. Tracks that hold full ground contact stop the machine scrubbing and re-climbing, which is where fuel goes when traction is poor. They reduce repair and ground-restoration costs, because a track that marks or compacts a finished surface costs money to put right. They cut downtime by failing predictably rather than suddenly, they lower operator fatigue through reduced vibration and noise, and they lift productivity because a machine that tracks straight and holds its line covers more of the job per shift.

Ground pressure is the number underneath all of that, and it is arithmetic rather than a specification. Ground pressure equals machine mass divided by total contact area. Take a 3,000 kg mini excavator with two tracks, each 250 mm wide and 1,600 mm of ground contact: each track has 0.25 m x 1.6 m = 0.40 square metres of contact, so the pair has 0.80 square metres. The machine's weight is 3,000 kg x 9.81 m/s2, about 29.4 kN, giving an average ground pressure of 29.4 / 0.80 = roughly 37 kPa, or about 0.37 kg/cm2. Fit a 300 mm track to the same machine and the average falls to around 31 kPa while the machine also becomes harder to pivot on a finished surface. Treat both figures as a model, not a measurement: substitute your own machine mass and your own measured contact length, and remember that the pressure under the front idler rises sharply whenever the bucket is loaded and the centre of gravity moves forward.

That mechanism explains the usual advice. A wider track spreads load, improves flotation and stability, and increases the effort needed to turn. A narrower or harder track puts more load into a smaller patch, which bites better in mud and rock and damages turf and asphalt. Steel tracks also tend to give greater traction on uneven and slippery ground, while rubber gives more controlled traction on flat or sensitive surfaces - a difference of tread pattern and construction, not of quality.

How to tell a track fault from an undercarriage fault

Four checks separate the two, and on most machines they take less time than a fuel stop.

Tension first. Lift the machine so the track hangs clear, then measure the sag where the manual specifies it - at the defined height, over the defined number of links. A track out of tension will not run straight whatever else is wrong. Then the sprocket. Creep the machine forward and watch the teeth: hooks worn to points, or a tooth pitch that no longer matches the track, will make a perfectly good track climb and skip. Then the idler and rollers. Flat spots, seized rollers and a worn idler face all produce a thump at walking pace, and every one of those thumps is transferred into the track. Then the track itself - cracks, torn lugs, exposed cord, and uneven side wear, which is the signature of a machine that pivots on abrasive ground.

Do all four on both sides. The two tracks stretch and wear at different rates, and a machine running one tight and one loose track steers badly and destroys the tight one first. A track that has visibly lost tension overnight is a separate case again: the usual cause is a leaking tensioner seal, and a cheap repair becomes an expensive one if the slack track is left running against the sprocket and idler.

When excavator tracks need replacing

Replace a track when you see deep cuts, large cracks or exposed steel cords; significant tread wear that has taken traction with it; frequent derailments or misalignment; or vibrations and noises that come from the undercarriage rather than the engine or hydraulics. None of those appear gradually enough to plan around. By the time the cords are visible the track has already stopped protecting the parts around it, which is why timely replacement protects overall machine health and keeps the machine working safely.

If you are doing the swap yourself, a replacement walk-through on a Bobcat 331 is a fair picture of the sequence and the tools involved on a small machine, and the order of work does not change much across models.

Maintenance that changes the outcome

Rubber tracks rarely fail from age. They fail from tension, cuts and contamination, and the routine that prevents all three is short.

Clean the undercarriage after abrasive work: packed material wears both the track and the frame, and gravel trapped in the tread cuts rubber from the inside. Check track tension on a schedule rather than a hunch, which on a busy machine means weekly. Inspect for cracks, tears, exposed cords and worn sprockets or rollers as part of the same walk-round. Replace worn idlers, sprockets and rollers as they appear, because they change how the track runs and how long it lasts.

Installation follows the same logic in reverse. Inspect the undercarriage components before the new track goes on, clean the mating surfaces, align the track carefully so it does not go on twisted, set tension strictly to the manufacturer's figure, and run a short test to confirm it tracks straight before the machine goes back to work. Daily cleaning and routine inspection from that point are what separate a set that reaches the end of its design life from one that does not.

Rubber, steel and the machine that does both

Some excavators do switch between rubber and steel depending on the job, and that is a reasonable way to keep one machine flexible. Running the two types together - one side rubber, one side steel - is not. Each track type is designed around specific terrain and performance characteristics, and a machine with mismatched tracks steers and wears unevenly.

If you change type, change the fitment question with it. Width, pitch and link count still have to match the machine and the drive sprocket, and the tread pattern still has to suit the ground, whether the belt is moulded rubber or linked steel. A track that is the wrong size for the undercarriage performs worse than a worn track that fits.

What to have in writing before you order

Track prices differ far less than the engineering behind them, and the difference is invisible in a listing photo. If you are still deciding between the two belt types, the comparison of rubber and steel track construction covers where each one is actually built to work. Six items are worth getting in writing, whichever supplier you use.

The cord construction - steel cord type and the number of metal inserts, because those are what hold the track's shape under load. The tread specification - pattern, purpose and depth as supplied, not as described. The joint - whether the track is vulcanised, and how the joint is inspected before it ships, because joints are where rushed manufacturing shows up first. The tension figure for your machine and the procedure for setting it. The published temperature band for the compound, since rubber tracks lose flexibility below the range their compound is rated for, and that band is a specification you can ask for rather than a rule of thumb. And a compatibility cross-reference naming your machine, its width, pitch, link count and the part number, plus warranty terms stated as a period and an operating-hours cap, whichever comes first.

Documents a supplier can produce on request - a specification sheet, a batch or mould record for the set actually shipped, a cut section showing the cord construction - are worth more than any claim printed in a listing. If a supplier cannot supply any of them, treat that as information about the supplier rather than as a gap in your own research. And if you are still choosing between sellers, the same three dimensions are what a track supplier working near you should be asked for before price is discussed.

This article is part of the rubber tracks guide, which covers how the size code works, tread patterns, compounds and buying a set in Canada.

FAQs

What are the tracks on an excavator called?

They are called tracks, and the assembly they run on is the undercarriage. The parts you will see named in a parts listing are the rubber or steel track itself, the drive sprocket, the front idler, the bottom track rollers and the top carrier rollers.

How much do excavator tracks cost?

Price follows width, pitch, link count, tread pattern and reinforcement level, so a single figure is meaningless without the fitment - a 250 mm standard track and a 450 mm heavy-duty track are different products built on different tooling. The comparison that means something is cost per operating hour against your own duty cycle, using the hours you recorded on the set you are replacing, plus whatever ground restoration and downtime the previous set caused.

Where can I find rubber tracks for my excavator?

Track manufacturers and their direct channels, authorised distributors, and general online marketplaces all sell them, with the same trade-off in each case: control and traceability at one end, price and convenience at the other. Start with the three measurements of the track you are removing, and treat any listing that does not state pitch and link count as unusable.

Do excavator tracks have to be replaced in pairs?

Not always, but the machine decides rather than the budget. If both tracks have run the same hours on the same ground, replacing one leaves the machine with two different wear states, and the newer track does the steering work. Replacing a single track is reasonable when the other is genuinely sound - check tension, lugs and cord condition on both before you decide.

What should I do with old excavator tracks?

Judge first whether the set can serve as an emergency spare: a track that still holds correct tension with intact lugs has a second life in that role. If it is stretched, cut or down to the cord, send it to a tire or rubber recycler rather than general waste, and keep the dimensions, link count and hours of the failed set on file - that record is what turns the next purchase from a guess into a calculation.