As a parts/accessories dealer, everyday, someone calls for help in selecting the right handlebar for their needs. Obviously they know the year/make/model of thier bike, but for the most part, there isn't a chart that says if you ride this bike and want the bike to feel like XYZ, you need ABC handlebars. So, how do you select the right handlebar?
The first decision is handlebar diameter. All off-road motorcycle handlebars are the same diameter out on the ends (where your grips are), but at the point of mounting (at the triple clamp), they are either 7/8 or 1 1/8" (AKA fatbars). The one exception that I can think of is the Easton EXP at 1 3/8". In the past, just about all stock handlebars were 7/8", but that's no longer the case.
7/8" Handlebar with crossbar
1 1/8" Handlebar
A key factor in this decision is how your triple clamp set-up currently is. There are two types of handlebar mounts. The first is a triple clamp where the lower handlebar mounts are cast into the top clamp itself. This is most commonly found on the Suzuki DR-Z and older Yamaha WR and YZ models for example. These are almost always OEM and come to think of it, I've never seen them from aftermarket suppliers. Typically cast handlebar mounts are 7/8", so if you want to run 1 1/8" handlebars, you'll need a set of 7/8" to 1 1/8" handlebar adapters (aka bar risers). It's important to note that when these are used, you have to factor the height they'll add into the total height that you want to achieve. For example, if you like the stock handlebar height and the adapters add 3/4" in rise, you'll need to find a handlebar bend that is 3/4" lower than stock to offset this. Outside of the standard handlebar adapters, some also come with a choice in height, adjustable height units and up/forward configurations.
7/8" > 1 1/8" Handlebar Adaptors
The second type of handlebar mounts are removable mounts. For this type, the lower handlebar mounts are secured by a stud that bolts through the top clamp (solid or rubber mounted) and are secured from underneath by nylon lock nuts and washers. The top bar mount bolts to the lower half and can be purchased in 7/8" or 1 1/8" sizes. Some mount the handlebar dead center while others have offset (usually 5mm or so), allowing you mount your handlebars fore (further from the rider) or aft of the center point of the bar mount.
7/8" or 1 1/8" Removable Handlebar
Mounts with 5mm Offset
There are also specialty mounts, like those from Rox Speed FX that are designed not only to accept standard or fatbars, have a choice a different heights, but they also pivot forward and aft. This offers riders another level of handlebar orientation flexibility, but is also something that has to be factored into the total handlebar mount and handlebar package.
The bike manufacturers know that there is a certain amount of cache associated with fatbars (perceived as an upgrade), but at least in my experience, I'm not sure the choice is that clear cut. Some maintain that 1 1/8" handlebars, which are typically crossbar-less (excluding the Renthal Twinwall Handlebar) have more progressive flex (less trauma to the hands/wrists and reduced arm pump), but outside of running Fasstco Flexxbars, I can't say that I've noticed any real difference between the stock Renthal 7/8's that came on my bike and the Pro Taper Easton Taperwalls that I've run in terms of feel and resistance to bending (both took some good hits). But, I'm 100% confident that you'll get different opinions here. However, I will say that having no crossbar seems to make the cockpit feel a bit more open and if you're running a top mounted steering stabilizer, its the only way to go.
Now that you've selected the handlebar diameter you want and how to mount them, you need to select the bend you want. In my experience, the best way to do this is to establish a baseline by confirming the key measurements of your current bars. The key measurements are width, height, rise, and sweep.
With the key measurements of your current handlebars, you can then compare the different values to the bend listing charts from the manufacturer for the handlebars you want. Think about how your bike feels and ask yourself what would make the bike more comfortable, both sitting and standing. For the most part, people that call us are looking for handlebars that are taller and with less sweep, as a number of handlebars come stock feeling like they are in your lap. Of course, the taller you are, the worse the problem.
It is important to note that changes in bar height greater than approx. 20mm+ will begin to cause some issues with your control cables. On my bike, when I installed a Scott's sub mount stabilizer, my bars were raised 25mm over stock. At full turn to the turn to the left, my throttle would not return to the closed position. I was able re-route the cable to avoid this, so be VERY careful with tall bar set-ups.
The right handlebar orientation is not only a comfort issue, it plays a key roll in allowing you to right in the right position on the bike. So, spend the time to get your set-up right for you. It really can help to make your bike more enjoyable and handle its best.