The frame of the roller ski has to provide strength to support the skier between the wheels with enough ground clearance to roll over the desired trail surface. Also, it has to provide a way to connect a ski boot or a person’s shoe to the frame. The frame can also have characteristics that can reduce road vibration and smooth out a few of the trail imperfections from effecting the ride of the skier. Frames are designed to mimic the feel of real skis. That is why most roller ski manufactures have separate frames for classic roller skis and skate skiing.
Current frames are constructed of a variety of materials including wood, fiberglass, kevlar, carbon fibers, and aircraft quality aluminum. The composite skis are generally more expensive, as they have greater strength to weight ratio. Some frames are also referred to as drop frames, with the axel of the wheels being above the top of the frame. The drop frame provides a lower center of gravity and is common on skis that use 6-inch and 8-inch pneumatic tires.
Over the past half-century, most roller skis have brackets for mounting the wheels on either end of frame shaft. Some have holes and slots machined into the actual frame shaft for mounting the wheels. A few manufacturers are designing the mounting brackets with a shock or dampening system to smooth out the ride, eliminating some of the road vibrations. Skike has just started selling an open-frame design that can be used with different size wheels. Them, along with other manufactures like Powerslide and SRB have frames that are also referred to as cross skates. TheSkike version has a binding system that can be used with a standard athletic shoe and contains a built-in calf brake.
Different types of frames have a different feel and handling characteristics that one skier may like and value, while another may not. It is good to roller ski with others so you can have the opportunity to try different skis before adding them to your quiver. Do keep in mind, you should try a ski multiple times before making that decision, as it may take your body a few times to adjust to some of the differences between a roller ski and a traditional ski. Many inline skaters find the skate feel of skis different and may be reluctant to roller skiing as they are not initially as efficient with them.
The fundamental design of roller skis has not changed much in the past 30 years, with the exception of braking systems, frame materials, road dampening vibration systems and the addition of the cross skate frame design that allows one to use a regular shoe. It is worth considering some of the benefits of these changes, especially when deciding which ski is best for the conditions that you will be roller skiing on most.