Motorcycle seats are made up of three essential parts: the baseplate, the foam and the cover (sometimes these are also referred to as the pan, the cushion and the top).
Before describing these three layers of a seat, you should know that some aftermarket or custom seat makers may use one or more parts of the original (stock) seat rather than actually provide you with all-new components. For instance, many custom seat shops simply take your stock seat off your bike and recover it with a different cover, just as an upholstery shop would recover your living room couch in a different fabric. Other custom seat shops might reshape the foam on your original seat and add their own cover.
If you and your passenger are comfortable on your stock seat and just want to change the look of your motorcycle, changing the cover on the stock seat is a reasonable way to go.
But for the large number of riders who do not find their stock seat comfortable, the best solution is a new seat “from the bottom up.” There are a few aftermarket seat manufacturers that create seats from scratch. The following describes these three basic seat components:
Seats are constructed on a single baseplate (both the driver’s seat and the passenger’s seat are built on the same, single baseplate) or a two-piece baseplate (two distinct seats). Both of the pieces on a two-piece baseplate can be attached for two-up riding or separated to ride as a solo seat.
Most stock seats and a number of less expensive aftermarket seats are built on plastic baseplates which are cheap to build but are far less sturdy than other materials. Higher quality baseplates used by aftermarket manufacturers are constructed of either marine-grade fiberglass, finished with a high-gloss gel-coat, or black, epoxy powder-coated 16-gauge steel.
The baseplate is the starting point in the design of a motorcycle seat. Ideally, the baseplate is designed to mount the motorcycle using the exact same mounting holes or brackets as the stock seat. (Nobody wants to drill new holes in their frame or fender.)
The notion behind creating an aftermarket seat is to make it far better than the original. That requires a good seat designer to roll the motorcycle into their studio, remove the stock seat and set it aside. Then, starting from scratch, the designer creates a baseplate as the foundation for a great seat.
One of the best ways to assess the quality of a motorcycle seat is to turn it over and examine the baseplate area or “underbelly.” When you pick up a premium seat, feel the weight and balance. That alone should show you how substantial a custom seat is compared to most stock seats.
It can be difficult to determine whether a baseplate is fiberglass or steel, but it’s pretty easy to tell if the baseplate is plastic. In some cases, you can actually flex a seat made on a plastic baseplate and literally snap it in two with a little effort.
Whether your new custom seat is built on a fiberglass or steel baseplate, be sure to look for the following features:
- All exposed brackets (visible when the seat is mounted on the bike) should be chrome plated.
- Polyurethane rubber bumpers should be strategically located and riveted to the baseplate to protect the paint and minimize vibration. (Bumpers made of polyurethane are ozone protected and will not crack with age.)
- The edge of the cover material should be hemmed, not just cut off and left ragged.
- The cover should be riveted to the baseplate at close intervals around the edges. (Most stock seat covers are merely stapled on.)
- Although not readily visible, if you were able to lift up the cover, you would notice that a steel-reinforced, impact-absorbing vinyl edgetrim had been secured to the edges of the baseplate to protect the seat cover material from wearing.
- A label specifying what make/model/year of bike the seat is designed to fit should be visible as well as the manufacturer’s name, warranty and contact information.
- Finally, complete mounting information should be attached to a replacement seat.
The most important component of seat comfort is the foam — and that includes both the shape and the quality of the foam itself. This is truly a case of “it’s what's inside that counts."
After creating the baseplate, an experienced seat designer will hand-sculpt the initial shape of the foam to carefully contour the shape to support your body and align your spine at the best angle possible to relieve back stress. And your mother had the right idea — sit up straight. It alleviates back pain.
Most seats are built as a single piece of foam that makes up both the driver’s and the passenger’s seat. Other seats are built as entirely two distinct parts — the solo seat for the driver is separate from the passenger seat. This two-piece seat allows for the removal of the passenger seat so that the driver can truly ride solo. Finally, a one-piece seat (built on a single baseplate but able to carry both driver and passenger) is sometimes designed to look like two separate seats.
Once the foam shape is created, a heavy-duty fiberglass (non-shrinking, isothalic resin) mold of this shape is created in which to “cast” the foam. The liquid foam solution is poured into the mold, which is then securely closed up. Within minutes, the chemicals react and the liquid is solidified within the mold in a process reminiscent of a giant waffle maker.
The chemical compound of the liquid foam is as significant as the shape. The structure of foam can be described as either open-cell or closed-cell. Think of the difference between types of foam, sponges or cushions on couches. Some foam is really soft and can be easily squeezed and almost flattened (open cell construction) while other foam is really firm and can barely be compressed (closed cell).
For a motorcycle seat to be comfortable, the foam compound must be carefully formulated to be soft enough for comfort but resilient enough to stand up to those "thousand-mile" days. The best aftermarket manufacturers use their own formula of controlled-density, polyurethane foam — a highly proprietary recipe, like those 13 mystery herbs and spices in KFC’s secret recipe.
A soft seat provides no support and is just as bad as riding on the bare baseplate. On the other hand, a really hard seat can make you feel like you’re sitting on a piece of plywood. Either way, your bottom will be in agony at the end of a day’s ride.
First-rate foam usually feels firmer than stock but it shouldn’t feel hard; it should offer “gentle” support. A good test is to stand next to the seat and press down on the foam. It should depress by about a third.
Most important, there should be no extended “break-in" period before you are comfortable. (Have you ever bought a sofa and been told you’d have to wait a month or so before it was comfortable?) A new motorcycle seat should compress and mold itself to your body shape within the first 15 minutes. The first ride should be as comfortable as the 100th and the foam should retain its shape and support for years.
Many riders ask about the use of gel in place of — or in addition to — foam. Gel displaces rather than compresses like foam. If you push down firmly on gel, it doesn’t compress. It just changes its shape (imagine a tube of toothpaste), which doesn’t do anything for your comfort. Foam compresses to supports your weight evenly over as large an area as possible.
Gel may be suitable for very high-pressure, thin applications in a limited area such as in bicycle seats or the soles of your shoes. However, to be fully supported and comfortable all day, your posterior needs the cushioning of high-quality foam — whether you are sitting in an office chair or on a motorcycle seat.
Most stock seats are covered with molded vinyl. The good news is that this prevents water from seeping inside. The bad news is that stock covers don’t provide a perfect fit when it comes to the contours of the foam mold or cushion. That means any discrepancies will result in wrinkles or bulges.
As with a custom suit or the upholstered cover on your couch, well-designed covers on aftermarket seats must be meticulously pieced together and sewn to fit tight contours for a true custom-looking seat. The best aftermarket seat covers are individually hand-sewn, not mass-produced.
Keep in mind that, unlike the molded vinyl cover on a stock seat, the process of stitching the covers of aftermarket seats creates tiny holes. While these can be filled with a waxy substance, water can still seep through. On a quality seat, water will not deteriorate the foam; it will just drip out through a hole designed for that specific purpose in the baseplate. To avoid damp rear ends, riders may fill the stitch holes with Pledge or another clear waxy substance. A note of caution here: Never apply wax to the entire seat — you do not want to be sliding right off the seat when going around a tight corner!
The most popular seat cover materials are leather or vinyl and there is a range of quality within each of these categories. Riders should choose the material that best meets their needs, preferences and budget.
Leather is more likely to be used by a smaller custom seat builder. It is premium priced and can be dyed in a variety of colors. Consider the type of riding you will be doing, where the bike will be stored, how long you want the seat to last and how much time you will devote to maintaining the leather on your seat. Many of us have leather jackets, gloves, purses, briefcases or leather seats in our cars, but few people leave these leather items outside, exposed to the elements.
Many major aftermarket manufacturers build seats with a vinyl cover. Depending on the grade, vinyl can be surprisingly similar to leather. The highest-quality expanded vinyl has the appearance of leather but has the durability and resistance to the elements that exceed original equipment standards for motorcycle seats. Maintenance shouldn’t ever be an issue with a premium vinyl — no fading, no treating or oiling. Just wipe it clean when you wash your bike. Unlike leather, top-grade vinyl will not dry out and crack, nor do you need to worry about it getting wet. It doesn’t fade and it requires practically no maintenance.
Whether made of leather or vinyl, look for the following features on the cover of a quality seat:
- All seams should be sewn twice for strength.
- The bottom edge under the seat that is attached to the baseplate should be hemmed.
- The edges of seats with skirts should be finished with braid.
- Pillow top seats should be tufted with covered buttons, which are double-tied with four cords, not two, so as to not lose their buttons.
- The cover and stitch pattern for each model and style should complement and enhance the shape of the seat and the flow of the motorcycle.
- Stitching should be evenly spaced, uniform and tight.
While some riders like seats that are plain, others prefer the look of decorative studs and Conchos on their seats. The best studs to use are chrome-plated brass that won’t rust. Top-quality Conchos are made of heavy die-cast zinc (not a thin stamping) and are hand tied with genuine leather straps.