Sports Cycle

The History of Motorcycle Frame, Suspension, Wheels, and Tires

The frame, suspension, wheels, and tires on a motorcycle are basically the things that hold a bike together and keep it from falling down. In the past, that was pretty much all they did, but modern designers use them for much more. The frames on early motorcycles were just a collection of tubes holding all the parts together. In the 1970s, however, designers began to realize that the stiffness of the frame affected overall handling characteristics and began experimenting with stiffer designs.

Motorcycle frames looked more or less the same from the time Harley and the Davidson boys built their first motorcycle until the mid-1980s. As a result of developments over the past 15 years, the twin-spar aluminum frames found on most modern sportbikes resemble the single- or double-cradle designs of the past about as much as an F-16 fighter jet resembles the Wright brothers’ Flyer.


Suspension, which refers to the combination of forks, shocks, and to a degree, tires, also has come a long way during the same time period. Just having a suspension was quite an innovation at one time. Early bikes relied on sprung girder forks up front and a soft saddle in back. It wasn’t until the 1940s and 1950s that most motorcycle manufacturers began offering the hydraulic front forks and swinging-arm rear suspensions we now accept as the industry standard.

Once accepted, this setup became engraved in stone : it didn’t change for the better part of 30 years. During the 1970s, dirtbike manufacturers developed a variation of the swinging-arm rear suspension that used a single shock, and that system found its way onto streetbikes in the 1980s. The advantage of these systems is that they allow the wheel to travel farther up and down when the bike strikes a bump or other surface irregularity before the shock reaches the end of its travel and transmits a jarring thump to the rider. By incorporating variable-rate linkage into such a system, designers have introduced even more suspension travel into the shocks. This type of system is the most common in use today.

Cruisers usually use the older dual-shock setup. Because of this, cruisers tend to be a bit harsher to ride than other types of bikes, but this setup also gives these bikes the retro look cruiser buyers want.

A few manufacturers have attempted to market alternatives to the hydraulic fork front suspension, most notably Bimota, with its Tesi model, and Yamaha, with its GTS, but neither bike has sold well.

BMW, ever the innovator, produces the most successful alternate front suspension - the Telelever system. This takes the shock-absorption function of a hydraulic fork and transfers it to a shock absorber located behind the steering head. This brilliant system solves many of the chassis-dynamic problems associated with a traditional fork, but I believe that part of its success can be attributed to the fact that it still looks like a traditional fork.

Wheels and tires have also seen a surge of development since the early 1970s. The first technological advancement was the advent of cast wheels in the 1970s. These allowed bikes to use automotive-like tubeless tires, which provide a tremendous safety advantage because they are less likely to blow out than a tube-type tire. If you have ever had a tire blow out on a car, you know you don’t want it to happen to you when you’re riding a bike.

The tires themselves have come a long way, too. When I started riding in the 1990s, we were lucky to get 5,000 miles on a set of tires. Today’s touring tires can last three times that long. And today’s radial street tires provide grip unheard of even in racing tires back then.

What all this means is that you have access to motorcycles that ride better, handle better, last longer, and are safer than anything a motorcyclist could have imagined possible just a few years ago