Skid steers are one of the most versatile machines in the construction world, but on wet, uncompacted soil, it doesn’t take much to spin the tires. When that happens you might as well cease work until conditions improve.
For the past 30 years, many contractors have done an end run around the problem by strapping steel or rubber tracks over the wheels of their skid steers and plowing back into the mud. OTT or over-the-tire track systems are a versatile, low-cost technology that is still popular despite the creation of dedicated compact track loaders with rubber track undercarriages.
“Compact track machines in some parts of the country are getting 50 percent of the skid-steer sales,” says Roddy Mears, regional sales manager for Loegering. “But there are always going to be rubber-tired skid steers and there will always be people who need an over-the-tire track they can take on and off.”
The biggest selling point for OTT tracks is they can add 30 to 40 work days per year to a contractor’s schedule – days he would otherwise lose to rain or sloppy conditions. “You start equating that with dollars and it’s quite a bit,” Mears says. Productivity is also enhanced. “Over-the-tire tracks make the machine more stable and act as a counterweight so the machine can pick up more,” he adds.
OTT tracks help lower the center of gravity of a skid-steer loader, says George Zafirov, marketing manager, McLaren Industries. “It reduces the possibility that the skid steer will turn over or flip forward or backward, especially if you are on a hill,” he says.
Another benefit you gain from OTT tracks with replaceable pads is that you can protect your tires from severe applications, says Zafirov. Steel or rubber pads can be easily replaced and prevent rebar, sharp rock and other obstacles from puncturing a tire.
Deere’s solid rubber tracks boost flotation and protect the tires from debris.
Hard or soft, solid or open
Before you buy tracks, know what sorts of jobs you are going to do, advises Zafirov. Do you need flotation, traction, tire protection, turf protection? Solid rubber track systems have integral lugs, similar to the tracks on small excavators and dedicated track machines. Open track systems have rubber or urethane pads or steel bars linked together. The solid rubber systems prevent debris from hitting the tires, but pad and bar systems are rebuildable. When you damage a pad or bar segment you just pull the individual piece and replace it with new.
Use rubber (pads or solid rubber tracks) anytime you are going to operate on concrete or asphalt to avoid scuffing the surfaces. You can drive a steel track over hard surfaces and not damage anything if you’re careful, says Gary Luther, sales manager, Grouser Products. But even the slightest turn or slippage will cause some grinding of the surface. In addition to rubber you can also find urethane pads that are non-marking, a requirement Mears says some municipalities now write into their specs.
Traction vs. flotation
The narrower the bar or pad, the more aggressively it bites into the ground. But it is possible to get too aggressive using OTT tracks. “There is the perception that a big aggressive track has more traction,” Mears says. “But you can take any track and drive it into the pile hard enough and you’ll kill the machine. You’re not going to spin the track.”
Operationally the biggest difference is once contractors put on a set of steel tracks, they usually don’t take them off again unless they move to a hard surface. Soft or rubber tracks are more like attachments, Mears says. You put them on for specific applications and take them off as soon as possible to prolong their life.
Quick change artists
Tracks can be put on in the field in 10 to 20 minutes regardless of the type. There are a couple of ways to do this.
You can lay the track out on the ground in front of your skid steer and then drive onto the tracks, says Laufenberg. Then flip the front and back ends of the track over the tops of the tires, ratchet the two ends together and secure them with a steel pin or hasp. This can be done by one person, but having two people makes it quicker and easier, he says.
For one-man installation of a heavy track, Mears and Luther recommend putting the track upside down on the ground with a rope or chain hooked to the first pad. Pull the front of the machine up to the track and wrap the rope or chain over the top of the tires and then under the rear tire. When you put the machine in reverse, the tires driving over the rope or chain will pull the track onto the tops of the tires and you can pin the track together where the ends emerge on the front tire.
Once they have the tracks off a machine, some contractors roll them up and scoop them up into the bucket for transport. Mears says contractors can save a little time at the jobsite by laying the tracks out flat on the trailer and rolling the machine on top of them. That way the tracks are secured for transport and you can install them on the trailer or drive off without them as conditions warrant.
One complication that may require additional time is if your skid steer’s tire-mounting position does not allow sufficient clearance between the inside of the track and the body of the machine. If you don’t have enough clearance, a wheel spacer can be bolted to your hubs to position the tire further out, says Luther. Bolting the spacers to four hubs may take an additional 10 minutes. Mears cautions that you should make sure the manufacturer’s literature mentions whether or not your brand of skid steer needs spacers or not, and that the cost of the spacers is included in the quote you get from the dealer.
Run loose for best results
The manufacturers we talked to will all recommend you install OTT tracks with between 1 and 3 inches of sag on the track between the wheels. A loose track does not degrade performance and a track installed too tight will pull the axles together, resulting in machine damage. Or, should a rock wedge itself between the track and the tire, the force – if there is not some slack in the system – could also damage the axles or bearings.
Mears also cautions that an aggressive track can be aggressive to your machine. “You have to remember you’re still on a skid steer. When you are spanning those two tires and not letting them slip, that strain is going to be taken out in other places, usually in the axle, the chain or the sprockets. Be careful of the material you’re turning on. Instead of counter-rotating 360 degrees, you need to think about making three point turns.”
For one-man track installation, hook a rope or chain to the first pad, pull the machine up to the track and wrap the rope or chain over the top of the tires and under the rear tire. Then put the machine in reverse so the tires driving over the rope or chain will pull the track onto the tops of the tires.
Running any rubber-tracked machine on a side slope can be tricky. Gravity pulling the machine downhill puts a lot of lateral force on the tracks, causing them to try to spool off the undercarriage.
Here OTT systems often outshine their compact-track loader cousins. The side guides on OTT tracks wrap around the sidewall of the tires, some almost to the rims, making it difficult for the tracks to move downhill.
Maintaining the manufacturer’s recommended air pressure in the tires is key to preventing detracking and avoiding tire damage, says Luther. “If you’re running an under-inflated tire on a sidehill, the tire is not only bellying out at the bottom, it’s rubbing against the tracks on the sidewall,” he says. “Pretty soon you’re going to wear through the rubber and into the cords. If you turn uphill in some cases you could pop the bead on the tire. But if you maintain the proper air pressure it’s pretty hard to throw a belt.”
Calculate the cost
Rather than view OTT tracks as just a rainy-day backup system, Mears suggests you calculate your hourly machine cost for a skid steer with a track system and compare it to a dedicated compact track loader. Make allowances for rebuilding the compact track loader undercarriage if you plan to keep the machine past its first lifecycle. If your skid steer with an OTT track costs $5 per hour to run and a compact track loader costs $11 per hour, that makes a big difference in the profitability of your jobs, he says.
But also keep in mind how much you’re using your OTT tracks and if that might not indicate you need a dedicated machine. “The over-the-tire track is a great stepping stone for somebody who is thinking about getting a designated track loader and wants to get a rough idea of how a machine’s performance can be enhanced,” Mears says. Choosing between a compact track loader and a skid steer with OTT tracks may also depend on how many machines you run, Zafirov says. If you have just one multi-purpose machine, unless you’re going to use it exclusively for landscaping or dirt work, you’re probably better off with the skid steer. “Sometimes you need tires,” he says.
And check with the manufacturer or dealer of your brand of skid steer before purchasing a track system. Most OEMs work with specific brands of tracks and you may run into warranty issues if you fail to follow the manufacturer’s guidance.
Comparisons with dedicated machines
OTT tracks and dedicated rubber-track undercarriages have some similarities, but their differences are important to note.
- Versatility. You put OTT tracks on or take them off as needed when conditions change. With compact track loaders the rubber is on for life – so they’re better suited to applications where you don’t spend much time on abrasive surfaces like concrete or asphalt.
- Flotation. You get the best flotation from compact track loaders. These dedicated undercarriages have rollers that help distribute the weight of the machine, says Doug Laufenberg, product marketing manager, John Deere Construction Equipment. Next best in the flotation department are solid rubber OTT tracks followed by OTT tracks with pads and finally OTT tracks with bar segments. Of the tracks with pads, the amount of space between the pads determines the level of flotation, says Zafirov. Less space equals more flotation.
- Cost. Compact track loaders can cost as much as 40-percent more than equal-size skid-steer loaders. But OTT systems are much less expensive, generally in the $3,000 to $5,000 range.