How does a synthetic shift cable that will never rust, doesn't stretch, and is made of the same material that holds the wheels on a Formula One car on in the event of an accident, sound to you? With 10,000 PBO fibers hidden within the length of a single cable, Powercordz have brought high tech to our simple cables.
Who else out there thinks that it is bit odd that we are still using steel cables to control shifting (and sometimes braking
) on our advanced modern bicycles? While there are certainly arguments to be made in their favor, they're cheap and easy to work with, there are also drawbacks to the time tested steel wire based system. Any rider who has had their shifting go haywire shortly after having a new cable installed knows full well how much a standard cable is affected by stretch. One minute things are dialed and the next it's like your derailleur has a mind of its own. It may only need a quick adjustment, but it can be a pain in the ass regardless. The larger issue is how easily susceptible a steel cable is to contaminates, even when used with fully enclosed housing. The alternative is a cable that doesn't stretch and doesn't rust.
Powercordz in 1.2 and 1.5 mm sizes
The solution, according to Power Cordz, is their synthetic cables that are claimed not to stretch and require readjustments or rust and corrode from bad weather or washings. As a bonus the Power Cordz system is claiming 45-60 grams of weight loss overall, which sounds like a lot since we're just talking about a few cables. Too good to be true? The heart of the Power Cordz system is their use of Zylon HM fiber (also known as PBO
) that is encased within a thin layer of smooth nylon. The PBO fibers actually number around ten thousand per cable and each strand is amazingly thin but strong. When holding the 1.2 mm diameter cord on your fingers it is hard to believe that there are actually 10,000 separate fibers running lengthwise that are hidden within. The nylon coating protects the fibers from damage and also helps to keep the cord running as smooth as possible. Further helping matters is Power Cordz' supplied housing that uses a fluorinated polymer lining that works well with the cord's nylon coating. An anodized aluminum cable end is then bonded onto the end of the cord and is tested to withstand 600 lbs of force, the same as its steel counterpart.
• Available in both 1.5 mm and 1.2 mm diameters to fit 5 mm and 4 mm housing
• The 1.2 mm size is compatible with all common shift systems (SRAM, Shimano, Campagnolo
• The 1.5 mm size may require slight modification to work properly with some shifters
• Compatible with Rohloff shifters and Nokon aluminum housing
• 1.2 mm cable weighs 2 grams, 1.5 mm cable weighs 3 grams (standard steel gear cable weighs 14 grams
• Manufactured in the U.S.A.
• Two year defect warranty
• MSRP $69.95 CAD (includes two shifter cables, housing, ferrels, and barrel adjusters
), MSRP $37.95 (includes two shifter cables
I never really thought of a standard gear cable as being heavy, there really isn't much to it. But holding a 1.2 mm Power Cordz cable in the other hand makes it clear that there is certainly a big difference although the numbers themselves are quite small. A steel cable comes in at 14 grams and the 1.2 mm Power Cordz at 2 grams. That's only 12 grams between them per cable, but the Power Cordz is seven times as light. Most of you will scoff at the weight savings but there are those out there who will appreciate it. In my mind the real advantage is the system's claim of far greater reliability.Installation and Riding
I installed three Powercordz shift cables, one for my rear SRAM derailleur, one for my HammerSchmidt, and one to control my KS i950r adjustable seatpost. I used the supplied Powercordz 4 mm housing and sealed ferrel's for each one.
While not overly tricky, the Powercordz certainly do take some extra attention and care to install correctly. I would urge anyone who is going to put these on their bike to read the instructions and watch the installation videos on the Powercordz website
. Straight out of the package the very end of the both gear shift cables were slightly frayed and needed to be trimmed clean in order to be pushed through the housing. Not a big deal, but make sure you use a sharp set of cable cutters in order to get a clean cut. I installed the 1.2 mm cable with the supplied Powercordz 4 mm housing and their sealed housing ferrels. An awl, pointy spoke, or some other tool that can be used to open up the housing after trimming is mandatory in order to feed the Powercordz cable through. Take the time to make sure all your housing ends are cut straight and not on an angle for the best possible performance. The cable itself is not as rigid lengthwise as a braided steel shift cable and trying to force it through blocked housing will only kink the cable and render it useless. Care needs to be taken when feeding it through the ferrels as well because of the O-ring seals in each one. Because of the slick nylon coating on each cable they do require a slightly different technique when it comes time to clamp them down at the derailleur. More clamping force is needed (don't go overboard here!
) and they require you to wrap the cable back around the bolt in order to get more contact area. Despite reading the instructions and taking my time, I managed to damage a cable as I tightened the cable anchor bolt. The cause turned out to be the washer under the cable anchor bolt had rusted in place and was turning with the bolt. The washer stripped off the nylon coating and I was left with exposed and frayed PBO strands. Hardly the fault of the Powercordz, but it highlights the delicate nature of the cables. The second time around I made sure that the washer was moving free and I had no issues. With two shift cables alone costing $37.95 CAD, you'll want to check those sorts of things before you install!
A damaged Powercordz due to wrong installation technique
Once installed correctly, the Powercordz moved quite smoothly through the housing. My rear SRAM system's high spring tension does hide some of the extra smoothness that the composite cables add, but those with lighter action Shimano shifters and derailleurs will certainly instantly notice an improvement in perceived shift effort. The obvious telling factor for me was the improved action of my cable activated KS i950r telescoping post. Because the KS remote lever doesn't use a return spring (the only return spring is located at the actuation arm on the post's head
), the slightest amount of cable friction is instantly noticeable. With the Powercordz installed the remote thumb lever for the post snapped back quickly, something it's never done with a standard cable installed. Also, there was next to no cable stretch. In fact, I'm betting that the small barrel adjustment that I made only needed to be done due to housing caps seating in. It's all well and good that the Powercordz worked great when new, that's to be expected for the price, but the advantage of not using a steel cable was more obvious down the road. Countless rides in terrible conditions that were followed up by irresponsible power washings have done nothing to faze the PBO shift cables. They are moving as free as the first day I installed them. Forget about the minute weight savings, for those who ride a lot, especially in less than ideal conditions, the Powercordz do make a lot of sense simply for the fact that they require basically zero maintenance. They are far more resilient to contamination than even stainless cables could ever hope to be. After countless miles I have encountered only a single problem. One of my bike's housing stops turned out to be not quite open enough to let the cable pass through without it rubbing against the aluminum. The nylon coating was quickly peeled off in that small section, exposing the PBO fibers within. Funny thing though, my shifting is still flawless. I plan on leaving it for now just to see how long it will hold up, but it should be mentioned that one of the nylon coating's jobs is to protect the PBO fibers from harmful UV rays.
Tensile strength - the force required to pull something to the point where it breaks:
* PBO - 5.8 GPa
* Steel cable - 2.8GPa
Tensile modulus - the ratio of stress to elastic strain where more stress is required to produce a given amount of strain:
* PBO - 270 GPa
* Steel - 200 GPa
* PBO - 1.56 g/cm3
* Steel - 7.8 g/cm3
A bit hard to tell from this picture, but the cable is wrapped around and back on itself to keep from slipping
The facts are that they are costly, finicky to install, and don't take kindly to being handled roughly. They also happen to require essentially no maintenance or adjustment at any point. I can see a lot of riders, myself included, being attracted to these for those reasons. Many readers will scoff at the Powercordz cables, but how many of those people have bikes worth $2000 and up in their garage that aren't shifting up to spec due to rusty $3 cables? With each cable costing roughly ten times as much as a standard gear cable, you'll have to decide if the Powercordz cables are for you.Do the Powercordz cables make sense for you, or are they completely out to lunch? Powercordz.com