Re-Imagining The Great American Road Bike

A Reader's Opinion

Editor's Note - When reader Phlip Buonpastore read last August's big touring cruiser test, he noticed something amiss with most of the bikes, and applying his engineering background as well as some liberal photoshopping to the problem, he came up with an elegant solution that would make for equally good-looking bikes with more luggage capacity and a lower center of gravity. -BB

As with any motorcycle made for travel, packing for the long haul is a necessity, and of course that goes for touring cruisers as well. With that in mind, there are certain choices in touring cruiser design that I have come to question somewhat over time. One such choice is the use of what is known as a "stacked exhaust" system, where both exhaust pipes are positioned vertically on the right side of the bike. In the recent Motorcycle Cruiser article entitled The Great American Road Bike-Big Bang with Bags Theory, this configuration is used on three of the six motorcycles tested. If you're an aficionado of cruiser styling, you know that this exhaust setup is common and not limited to full-sized cruisers. It is also used for many of the newer class of "mid-sized" touring cruisers (as well as cruisers not designed for travel) so observations here would apply to these bikes as well.

Publicity photos of motorcycles designed this way almost invariably show the right side of the motorcycle. Why? Because this side is more visually-appealing than the side without the exhaust. A photograph of the left side of the motorcycle, while still attractive, is less so, and the overall affect when both sides of the bike are compared is something of a visually unbalanced look. In photos featuring the left side of these bikes, you may notice as I do that the saddlebag looks somewhat abbreviated-that is, it is sized vertically shorter than the amount of room available for it. Of course, its size is dictated by the size of the bag on the exhaust side, which is shortened to fit above the stacked exhaust.

But what else does this engineering and style choice impact? Well, in the case of a bike designed for long distance travel, it impacts several important areas of the job that the motorcycle is designed to do. The first is to provide the necessary storage space for long-distance travel.

Using a bit of Photoshop magic, I have altered a PR photo of the Victory Kingpin Tour motorcycle to illustrate a few points. The first example is an image of the bike altered to show how it might appear with a common two-into-one exhaust used by other bikes in the comparison:

While some might say that this change in styling is not as flashy as the stacked exhaust, you can immediately see how a relatively minor change in exhaust configuration would allow an increase in the size of both saddlebags by nearly 50%. This would probably translate into somewhere near 33% overall increase in storage capacity (including the trunk), while eliminating the abbreviated look of the bag on the left side. The larger bags would also allow packed weight to be carried lower on the bike, bringing down the overall center of gravity, which would likely aid in slow speed stability. While those would all be pretty solid reasons for the change, what else might it accomplish? Well, just of the top of my head, I'd say it would allow for a slight upward relocation of the exhaust system, helping to increase cornering clearance and lean angle, one of the common complaints of almost all cruiser-styled motorcycles.

Taking it a step further, a company could also change the exhaust configuration to put one pipe on each side of the bike. For this rendering, I reversed the right side image and added the drive section from a Victory Vision, so while the mechanicals will not be 100% accurate, I think you'll see my point.

Besides the already increased saddlebag size, making this change would also create a look that is more visually balanced on both sides of the motorcycle, keeping the look of the bike essentially the same coming or going. Using two pipes would also eliminate the need for any engine tuning changes (to accommodate any change to muffler size, performance mapping for two into one exhaust, etc.), and upward repositioning of the exhaust pipes would again be possible here, again allowing better cornering clearance.

Finally, how about this idea? In the review, the Victory was the only motorcycle available with a trunk-passenger backrest. Mention was made of the convenience of being able to move the trunk-backrest forward and back 1.5 inches to accommodate passenger comfort. Well, what if you're traveling without a passenger? It's a very nice backrest. Why shouldn't the rider get some benefit from it? How about making it adjustable by 1.5 feet (see lead photo on page 63).

While the backrest cushion might have to be repositioned downward for it to be more usable for either rider or passenger, you get the idea. Putting the trunk on rails and allowing it to move it forward or back as needed would accommodate any rider and passenger size. It might even be designed so that it can be removed from the bike for more of a "standard bagger" look, should the owner not need the extra packing room. Just a guess, but I would imagine that with the trunk in its full forward position, a larger air envelope would be created around the rider, for a quieter ride with less buffeting.

While everyone has their own opinion on style choices and the modifications shown here might not appeal to everyone, most would probably agree that these changes would increase the functionality and purpose that the bike was designed to do. Most full-dressed touring models, including Victory's Vision, Harley's Road King and Glide series, and Honda's Goldwing already use an exhaust pipe on each side of the bike, and those bikes all gain the benefit of increased saddlebag capacity because of it.

As a guy with an engineering background, I have always been a big fan of the "form following function" idea. I think it would be a good day for motorcycling in general when manufacturers not only take a bike's style into account, but also incorporate design ideas that increase the usability of features and amenities for their prospective buyers. It is my guess that they would increase the number of prospective buyers in their dealerships because of it.

Photoshop customizing at its best with relocated box and 2-into-2 pipes. Better storage, weight distribution, a rider backrest, as well as ground clearance and a balanced look.
Stock Victory Kingpin Tour
Switching to a 2-into-1 exhaust on the kingpin makes for more storage and lean angle, like the Stratoliner above.
The two-into-one exhaust used on the Star Stratoliner allows for a larger bag on the left side of the motorcycle, which visually "balances" the left and right sides of the bike, and increases storage room as well.
The author's conception of a dual-sided exhaust and larger bags on a Kingpin Tour.