After our previous blog posts about extending your motorcycle cables and brake lines, and another about measuring for comfortable bars, we thought it’s about time to take on the topic of cables all by themselves.
Let’s start with HD throttle cables. In this modern era we use a two-cable system, something that was mandated by the government to preclude sticking throttles. In case the throttle does stick, the two-cable system has a positive action when the handgrip is closed, closing the throttle.
Through the decades, we’ve experimented with three types of cables. The first cable was used on “butterfly” type Keihin carbs that were common on Big Twins from 1976 to ’89 and XL’s from 1976 through 1986. The second cable was used on CV-style Keihin carbs found on Big Twins from 1990 to 1995 and XL’s from 1987 to 1995. The third cable type was used from 1996 to 2008 on all models, and from 2009-10, all model except FLT Fly-by-wire systems.
First, a look at the differences: Most cables are measured in outer housing length only. Something to remember is that what’s standard for one model bike may be plus-6 for another model. For example, the difference between the butterfly Keihin cables and the CV Keihin cables is the internal wire length. Later style cables have a longer internal wire. On models up to 1996, both cables have a threaded portion that screws into the switch housing. Pull cables (throttle) have different thread diameters than Push (idle) cables, so it’s pretty difficult to install them incorrectly. Another identifying feature of an idle cable is a quarter-inch-long spring at the bottom of the cable. Those dating from 1996 and up are no longer threaded and instead use a clip to hold the cable in place. Wire length and different diameters are the same for models 1996 and up.
Who cares, you ask? Why do we even need to know this? A popular modification for bikers these days is to convert to the S&S Carburetor. When this carb was designed, the butterfly Keihin was in use, so the designers at S&S set their carb up to accept the stock cables of the era. This was fine until 1987 on XL’s and until 1990 on Big Twins when the carburetor changed. The cables used on the CV were not compatible with the S&S. Because of the way the cables screwed into the switch housing, the easiest solution was to retrofit the stock butterfly Keihin cables to the later model bike. But in 1996, there were no stock cables that could clip in with the proper wire length to use with the S&S. But the aftermarket was quick to jump in with special cables for this application. These special cables worked just fine. Then in 1999, S&S redesigned the cable bracket on the carburetor to allow for the use of the “CV” type cables.
Now there are a ton of carburetors out there that can still work on later model bikes if this updated bracket is installed. The S&S (J&P) Part Number for this bracket is 400-684. To help identify the two brackets, the earlier unit has relatively flat tubes for the cables while the later bracket has tubes that are raised about an inch.
Once again, the dimension given for clutch cables is the housing length (with the adjuster fully collapsed). What’s really great news for the consumer is that on Big Twin models from1987 through 2003, the clutch cables interchange between models. Once you have determined the length of cable you need, look at the various models and select the length you need. Since 2004, the FLT series bikes and the XL cables use the same design, so cables in these families interchange.
Each manufacturer has different designs on the various models. While Harley cables interchange between models, the metric cables cannot be interchanged. This makes things a bit harder, but you metric riders need not despair. We have some previous posts regarding selecting cable length. You can find that here. Once you have determined the proper length, you can call your friendly J&P tech and he can place a special order to get whatever cable length you require. A couple of things you must know about special order cables: Measure carefully! The only way to return a special order cable is if it’s defective, so again, please measure carefully. There are no returns if it’s the wrong length. The second thing you need to know is that it’s going to take four to six weeks for the cable to arrive. That’s because these cables are custom made to your dimensions.
That concludes today’s blog post. I hope you have a better understand of how to order cables. As always, your questions are welcome.