There are three central questions about size you'll need to ask in your search for a skid steer loader.

The first major consideration is the physical size of the machine: carefully measure any gates, garages, or in other small spaces your skid steer needs to fit through. Typical skid steers range in width from about 3' to over 6', while heights are usually between 5' and 7'. Knowing your height and width limitations is a very simple way to narrow your choices.

A second point to address is how high you need the loader to lift: if you need it to fill a 9' high dump truck, make sure the model you choose has the appropriate dumping height. This is usually measured as the "height to hinge pin," meaning the pivot point between the arms of the loader and the bucket. It can range from around 8' on smaller models to over 10' on the largest.

Most skid steer purchases are driven by these two factors - physical size and dumping height - because they're often inflexible. The third main consideration is lifting capacity, also known as operating capacity. It's also very important, but you'll usually have more flexibility here. As lifting capacity increases, the physical size will increase as well. If your primary consideration is access to tight places, you may have to settle for slightly less carrying capacity.

According to Compact Equipment magazine, the most popular size is the 1,750 lb to 2,200 lb range. Generally, anything over 2,200 lbs is considered a heavy-lift skid steer. In recent years, several manufacturers have introduced skid steers that can handle over 3,000 lbs, but businesses that require that much capacity often turn to full-size front end loaders or other heavy equipment instead.

Tires
The main choices for skid steer tires are pneumatic - hollow rubber tires filled with either air or polyurethane foam - or solid rubber tires.

• Air-filled tires are the best at smoothing the ride on bumpy or uneven surfaces, but you run the risk of getting a flat. They're also the least expensive.
• Foam-filled pneumatic tires are impervious to flats, but are more expensive: they can cost $400 each. In addition, since foam-filled tires are so much heavier than air-filled, they put additional strain on the skid steer's transmission and can lead to breakdowns.
• Solid rubber tires are typically much thinner, so they don't have the weight problems, and also never go flat. However, they do give the roughest ride.

If you plan to use your skid steer primarily on paved roads or smooth surfaces, or if your operating environment has lots of puncture hazards (such as a recycling center with lots of broken glass), solid rubber tires can be a good choice for longevity. In most general-purpose use, though, air-filled tires are the most economical and comfortable choice. By reviewing what multiple providers can offer, you'll get a clearer idea of which steer loader tires are the best fit.

Skid steer alternative
A near relative of the skid steer loader is the compact track loader. Also known as a multi-terrain loader or rubber track loader, it's basically a skid steer body mounted on dual treads -- like a tank or bulldozer -- instead of wheels. The main advantage of a compact track loader is that treads get better traction than wheels in mud or loose terrain. Also, because the weight of the loader is distributed across a much larger surface, track loaders often do less damage to the ground they're used on than wheeled loaders.

Overall, track loaders tend to be bigger, with more capacity and correspondingly higher prices, so they're generally purchased either as part of a fleet of construction vehicles that also includes skid steers, or for applications where they'll be used on loose terrain most of the time. If you only need tracks occasionally, it's possible to buy conversion kits that let you attach treads to a standard skid steer - they fit right over the wheels.

Evaluating multiple models
Once you've narrowed down your choice to some models that are the right size for your needs, try them out. Evaluate these aspects of each one:

• Comfort. A skid steer loader operator may be in the cab for hours at a stretch. Is the seat comfortable? Are controls easy to reach? Is it easy to get in and out?
• Visibility. Good vision can speed work and reduce accidents. Can you see the edges of the bucket from the seat? Can you see reasonably well to the sides?
• Maintenance. While tough, skid steers do require constant maintenance. How easy is it to access the engine and hydraulic pumps? What is the recommended service schedule like?

Operating capacity for a skid steer is set at 50% of the tipping load - the point at which the rear wheels lift off the ground. The industry classifies skid steers into nine categories: