Product Highlight – Top Gun KLR650 Chainmaster

KLR-650 Chain Master Upper Chain Run Control Device*
(*Engineered using a stock KLR-650 with properly adjusted chain.)

 

You know we are big fans of the KLR-650 and we think it’s one of the two finest big-bore multisurface motorcycles on the market. For some reason though, the folks at Kawasaki have produced a motorcycle for off-road use with minimal lower, and absolutely NO upper, chain run control. Look at any other off-road bike, like the DR-650, and you’ll find some sort of chain control, most commonly rollers. Elden noticed this problem more than ten years ago and installed his own chain roller. The only problem with Elden’s method was that it required some nifty handiwork to drill precisely through the sub-frame to provide a location for installation. Fast forward to 2006, and we asked Old Top Gun to take another look to find an easier solution. What you see here is the culmination of a lot of research, a lot of time with a KLR-650 up on the lift, some fine work by the good folks at MacDonald Products in San Diego, and another tangible example of Elden’s innovative problem solving ability. This is our first “neccessory” for the KLR-650. A great term coined by Elden, it describes those items that may be aftermarket upgrades, but are vital to the long-term health of your ride. In our minds, there are four neccessories for the KLR-650: upgraded balancer lever (we prefer the 08+ OEM lever) and tensioner spring with an inspection port; a properly sized straight-wound rear spring; a MacDonald Products upgraded shift lever; and now the Chain Master. All of these products share one thing in common – Elden conceived or collaborated on every one – and all can be found at MMP.

Why do you need a Chain Master? There are three main reasons that any KLR-650 rider needs a Chain Master:

  • Protect airbox vent
  • Reduce chain slack at full rear suspension compression
  • Allow better engagement of the counter-sprocket by the chain during rear suspension compression

On the KLR-650, the airbox vent tube lies directly above the chain and bears the brunt of this omission. In the picture to the left, the airbox vent-tube cover has been torn by the chain. This damage obviously defeats the purpose of the vent cover by creating a larger opening for dirt and dust to enter the airbox. Over time, the damage is more dramatic, as evidenced by the picture to the right. Here, the cover for the vent tube has been completely torn away, and the abrasion damage from the chain to the tube itself is easy to see. The Top Gun Chain Master is designed to take advantage of existing frame fittings to place a chain roller in the proper position to control the upper-chain run. The Chain Master comes with simple to follow instructions, as well as all hardware necessary to complete installation. It is made with only high quality components; even the fasteners included are significantly stronger than those installed by the factory. By installing the Chain Master, you will effectively upgrade your lower left subframe bolt!

Many KLR-650 riders are unaware of this problem, but even street-only riders will benefit from this protection. We gave a Chain Master to an experienced rider associated with a major motorcycle publication for testing. During a stop, he struck up a conversation with a fellow rider who happened by on another KLR-650. The conversation soon turned to our product, and the other rider commented that he didn’t think the KLR needed a chain roller. After a quick explanation of its benefits by our test rider, they walked over to the other rider’s KLR, only to find that the vent-tube cover had already been torn off!

The following pictures were taken using a KLR with a properly adjusted chain. If your chain is loose, or if you have installed lowering links without properly adjusting your chain slack measurements to account for your new swingarm position, you will have more chain slack than depicted. The two pictures below are taken with the swingarm at stock-shock close. That is to say, with stock shock and links, your swingarm should not rise any higher than this. The picture on the left shows the Chain Master engaging the chain (note: actual product has a black chain roller; the white roller was for testing purposes only but is the same size). The picture on the right shows the same swingarm position without a chain roller, and with maximum upward deflection, as occurs with a low throttle position while the suspension is fully compressed. Notice that the chain is more than capable of hitting the airbox vent-tube cover.

We designed the Chain Master using a stock KLR-650 with stock rear suspension and a properly adjusted chain. We still wanted to see what would happen at maximum swingarm travel. In this case, the muffler on the right side of the bike is actually contacting the swingarm. We would like to think getting to this point would be impossible. Unfortunately, we have seen KLR-650’s with modified suspensions – particularly, improperly installed lowering links – where the muffler was indeed impacting the swingarm. Notice in the next figure that the Chain Master is still able to control the upper chain run.

Even at chassis contact, past normal shock close, the Chain Master is working.

Even at chassis contact, past normal shock close, the Chain Master is working

As we mentioned, the Chain Master can also help reduce chain slack during swingarm movement. Take a look at figures 1, 2, and 3 below. Since the swingarm pivots at a point that is not co-located with the counter-sprocket, the chain will be at its tightest when the counter-sprocket, swingarm pivot, and rear sprocket are aligned (figure 1). Our test bike had 15mm of slack at its tightest point. Figure 2 depicts a “normal” condition, as when a rider is sitting still on the bike. On our test bike, the chain had approximately 25mm of chain slack at proper ride height. Notice that the distance from counter-sprocket to rear sprocket is shorter than in figure 1, as represented by the triangle formed by the counter-sprocket, swingarm pivot, and rear sprocket. The same thing happens in figure 3. Even though the swingarm has passed above the tightest position, it still follows the arc defined by the swingarm. As the swingarm travels further from the position in figure 1, ever-increasing slack will be present in the chain. At stock close, our test bike had 41mm of slack. When we installed the Chain Master as in figure 4, our test bike had only 26mm of slack at stock close. Notice that the chain slack has been reduced to approximately the same amount as during normal riding. What can this do for you? Think about anytime you’ve worked with a rope. If you and your friend each hold one end and your friend tries to jerk it out of your hand, there’s a big difference in apparent force when there’s slack in the rope as opposed to when it’s taut. The same thing happens to your chain, and that jerking force contributes to chain stretch and sprocket wear.

As mentioned above, chain slack contributes to the wear and tear on your chain and sprockets. Another advantage to the Chain Master is that it helps guide the chain onto the counter-sprocket earlier, allowing it to more fully engage the sprocket. This earlier engagement helps spread-load the forces acting on the sprocket, which should reduce wear. The pictures below depict the ability of the Chain Master to help guide the chain onto the counter-sprocket. Notice the change in the angle of the drive chain between these two photos.

We won’t try to sell you something you don’t need. This product has been tested on our own bikes (as well as by experienced, objective test-riders), ridden hard both on the street and off-road in Baja. We have been extremely pleased with its performance, and we honestly believe you will too! You can find yours here, courtesy of MMP.