You all know what I'm talking about: Its the "Why does my bike always make that clicking sound? Why do my brakes rub? Why does my chain keep falling off? Why does my bike 'ghost shift'?" type of questions that indicate that there is a problem. Often the problem is a simple tune-up. Other times it is simply poor component choice.
So, we all know that I spend way way way too much time researching bikes and bike related goodies... don't need to beat that horse. But, perhaps I can share some of the things that I have found out during my sleepless nights that can benefit you all.
I recently finished building up my new time trial bike for my upcoming triathlon season. Here is a gratuitous carbon shot:
Over the next few weeks, I am going to dissect each of the things that I chose to use on my bike and why... should be fun!
We'll start today with something small and often considered insignificant: cables and cable housing! All the same right? You just go to your LBS (Local Bike Store) and tell them you want new cables... WRONG!
All cables were not created equal! So, what are the important factors to consider:
- Steel vs. stainless steel
- Coated vs. uncoated
- Stretched vs. unstretched
Our bikes ride through mud, rain, sand, worm guts, etc... so the benefits of a stainless steel cable over a standard steel cable should be obvious. Stainless steel resists corrosion, so will greatly prolong the life of your cables and eliminate some need for frequent lubrication.
Next, some cables come coated with a low-friction substance (typically teflon). This decision is a bit trickier. Whereas the teflon can again help stop corrosion and help the cables run smoothly through the housing for precise shifting... the coating can often wear down and flake off causing a build up of teflon-gunk causing your bike to shift like crud. This is especially the case if you use SRAM road shifters, as I do. SRAM shifters force the cables though very tight bends within the shifter itself... and this makes a great place for teflon-gunk build-up. So, my vote here: non coated cables! Instead, I recommend simply lubricating your cables more often. Just use a light chain lube (not wax based... Pro-Link or Dumonde Tech are my choices) and coat the cables and squirt some into the housing as well. Do this once a month and you'll be set.
Third, stretched vs. unstretched cables. This one is mostly a thing of the past, as 99% of cables come pre-stretched these days... but still worth knowing about and looking into. Since our cables are simply wound up strands of steel and steel is malleable... it is prone to stretching out when tensioned. Now when a cable is mounted to a bike it is always under tension, so it will cause stretching to occur, which in turn will affect your bikes shifting... for the worse! So, pre-stretched cables do exactly what the name implies. The cables are tensioned and stretched in a machine before they are sold. This is a great thing, as it decreases the chances of the cables stretching out on our bikes, so cuts back on the need for constant derailleur adjustments. Pre-stretched cables are a good thing.
So, that explains a few things about cables. And don't forget that cables also come in a variety of types: brake cables are not the same as shifter cables, Shimano cables are not the same as Campagnolo cables, etc. So, make sure when you buy your next stainless steel, uncoated, pre-stretched cables that you know exactly which type you need!
The next foray in this blog is into cable housing! Just as cables have important differences, the housing around it does as well. The most important difference in housing is being able to differentiate between brake cable housing and shift cable housing... and that can be a deadly mistake! You see, housing is made up of an inner plastic liner, a reinforced steel layer, then an outer plastic layer. The inner liner helps reduce friction against the cable, the steel structure provides the strength, and the outer liner holds the steel in place and protects it from the weather. The difference between brake housing and shift housing is in the design of the steel layer. Brake cables/housing need to be withstand really high forces (think about descending down a steep hill and squeezing your brakes with all your might), so the steel layer in brakes housing is one really long straand of steel wrapped in a tight helix from one end to the other (see picture). This makes it extremely strong and ensures that the cable cannot break through the housing under high-load. This also makes brake housing very heavy. In comparison, shift cables/housing experience very low forces (just the strength of the springs in your derailleurs), so they do not need the 'beefiness' of the braking system. Therefore, the steel layer in shift housing consists of very thin strands of steel lined up next to each other in a circle that again run the length of the housing (again, see the picture).
Brake Housing - Shift Housing
Now, a couple of important consquences of housing design are flexibility, weight, and compression. Flexibility being the most important. You see with all that steel inside the housing, they become rather inflexible (especially considering some of the tight bends required for TT bikes, full-suspension mountain bikes etc.) and prone to kinking. If you housing gets kinked or pinched, your shifting and braking will be greatly affected and you'll need new housing! So, that is a major downfall. Then the weight factor, with all that steel, housing is heavy for us road biking weight weenies! Lastly, compression. Our bikes shift and brake because the cables pull against the rigid structure of the bike frame and the housing... so any 'give' in that system creates sloppiness in our shifting/braking. Which brings me to compression. Since our housing in made up of strands of steel and plastic liners, when placed under load, that system will 'give' just a little bit as the steel strands compress together. That little bit of compression can result in substantial losses in performance.
All this leads to my unique choice in housing: Nokon Cable Systems! The nokon system completely eliminates the steel and instead uses lightweight aluminum cylinders for the housing. Therefore, they are still extremely strong, but since they are small individual pieces they are much more flexible to make tight bends. In addition, the aluminum won't corrode, so the need for an external plastic layer is eliminated. Inside the the cylinders nokon uses a reinforced liner that still allows for an extremely smooth surface for the cable to run through. Lastly, since nokons use 100% solid pieces of aluminum, there is NO COMPRESSION! And again, no compression means noloss in shifting/braking performance.
In short, nokons are lighter, more flexible, and allow for more precise shifting than any other cable system on the market. And they look wicked cool too! :-)Next Blog: Shimano, Campy, or SRAM?
