He goes on to explain that Wacker's large roller gives the operator added versatility over its smaller counterparts. He says each vibratory drum offers a choice of high or low compaction force to fit a variety of conditions and applications. The lower centrifugal force is ideal for asphalt conditions whereas the higher centrifugal force is better suited for work in granular subbases.
Both Monical and Sirmons emphasize that drum vibratory versatility is one of the benefits that comes with larger machines. All their midsize units feature independent drum vibration to match the application and water systems that keep the drums free of asphalt buildup.
Before upgrading to a larger roller, Conrardy says contractors should ask themselves if there will be enough work to justify going to a bigger machine.
"They should ask themselves how long will it take to payback the incremental difference in price with additional work. If the time frames and upgrades are worth the extra work that can be done, then the answer is 'go for it.'"
Adds Monical, "Some contractors use smaller commercial jobs as stepping stones to larger projects. Others do a great job with the smaller jobs and are content to stay there. Before buying a new roller, it's important to know which type of contractor you are. If you're planning on moving up to even larger projects, then a higher-end midsize roller would be in order."
"Certainly, there is a direct relationship between size and cost, with more steel and a bigger engine, hydraulic system and vibratory system in larger units," Monical says. "Maintenance costs will go up, too, as contractors upgrade, but that expense is more directly proportional to use than it is to the size of the machine."
Another important question to ask is "will my new roller be compatible with my current equipment lineup?" Going up in roller size often means getting a bigger truck and trailer, and possibly a new paver. To get optimum use out of all your paving equipment requires that their capacities reasonably match.
Options. In terms of special "bells and whistles," manufacturers incorporate most of them as standard equipment, including ROPS and seat belts. Hamm, for example, offers only two options on its midsize units - a couple of additional work lights and a flashing beacon.
Durability. Sakai's Sirmons notes that in their search for a new roller, contractors will likely come across "cost-down" units. "The price may be attractive," he says, "but the long-run maintenance costs will more than likely make up the difference in a hurry. Make sure to buy a machine that is well built. Durability and technology can differ from model to model and manufacturer to manufacturer. Look for solid steel construction with heavy-duty components, and make sure you're getting a machine with the latest model engine that meets current CARB and EPA standards."
In general, manufacturers advise contractors to take it one step at a time while moving up the paving ladder. Fit your roller to the application, all the time considering how it will mesh with the rest of the equipment in your paving lineup. Glance into your crystal ball. Determine what types of projects are in your future. You don't want to buy a machine that you will outgrow tomorrow. You also don't want a machine that, as Monical says, will be too big or hit too hard for current projects.