your brake and shift cables connect you to your brakes and derailers and are what you use to tell your brakes and derailleurs what you want them to do most cables are open to contamination especially in wet conditions cables that are rusty dirty or clogged with the wrong lubricant disrupt the connection between you and your brakes and derailleurs and make even the best braking and shifting systems working consistently or not at all in this video we demonstrate in three easy steps how to cut trim and lubricate your cables to ensure precise reliable braking and shifting that will remain consistent through any condition depending on what you're trying to do you'll need brake housing brake wire and metal end caps also known as Ferrell's to put on the ends of the housing as well as shift housing shift wire and metal or plastic Ferrell's depending on the diameter of your shift housing you'll also need a good set of shear cutters like these Falco cutters or the park to a cable and housing cutter a tool with a sharp point in this case a sharp and spoke and finish line extreme fluoro a fully fluorinated low viscosity lightweight grease step one knowing your cables brake and shift cables differ from one another in a couple of ways they both comprise two parts an outer covering called housing and an inner wire that's inserted into the housing brake housing consists of a long coiled strip of wire that's protected from moisture by a plastic outer sleeve most modern brake housing also contains a plastic inner liner to reduce friction between the housing and the inner wire in the past before index shifting provided us with the clicks we all know brake housing was used for both brakes and shifters by contrast shift housing is designed for stiffness in response to the demands of index shifting systems that won't shift precisely with flexible brake housing the stiffness is the result of long strands of wire that run parallel to the length of the housing instead of being coiled into a spiral like brake housing shift housing is protected by a plastic sleeve and often contains an inner liner however you should never use shift housing on your brakes because it can burst under the high loads of braking next up is the inner wire here again we see a difference between brake and shift cables in fact braking or wire actually comes in two varieties one for road bike brake levers and one for mountain bike brake levers the two different respect to the small metal head that's found at one end of the wire some cable manufacturers actually sell wire that has a road head at one end and a mountain head at the other allowing you to clip off the head you don't need installing the inner wire into your brake levers perhaps the easiest step in installing a cable in the case of Road wire when you pull on your brake lever and look inside you'll see a small part with a specialty machine hole in it simply insert the end of the wire without the head through that hole and continue pulling the wire through the lever either from the back in the case of levers like this Shimano STI lever or at the top in the case of some older levers once you've pulled the wire all the way through use your fingers to seat the head of the wire into that specialty machine hole and let go of the lever to close it don't worry if the head doesn't stay seated you'll have plenty of opportunity to make sure it's seated before you finish installing the cable installing the inner wire into a mountain bike brake lever is very similar maybe even easier mountain bike brake levers have an opening for the head of the wire on the outside of the body and usually on the underside of the lever the body also has a slot in it as does the knurled insert that threads into the body and allows you to adjust the cable later and the lock ring that holds that insert in place to install the inner wire first line up the slots then insert the head of the wire into the opening in the lever body once you've done that guide the wire into the slots and last of all rotate the insert the lock ring or both so that the slots are no longer lined up this will keep the wire from falling back out as you complete the installation shift wire is the same for Road and mountain bike shifters in both cases a small cylindrical head at the end of the wire fits into a specially machined hole in the shifter on this Shimano STI lever you insert the end of the wire without the head into the side of the shifter then pull it out the other side and seat the head like you did with the brake wire if the wire won't go in check to make sure that the shifter has shifted all the way down to the smallest cog if it's a rear shifter or the smallest chainring if it's a front shifter insert the wire into a mountain bike shifter the same way first check to make sure that the shifter is shifted to the lowest position for the smallest cog or the smallest chainring and then run the wire through seating the head of the wire into the shifter with your fingers when you're done step2 cutting the housing this is where the right set of cutters can make your life a lot easier cutting break housing is actually very easy once you've correctly sized the housing place it in between the jaws of the cutter and squeeze the excess housing will come right off however if you look closely you might notice that the metal coil was cut in the middle leaving a spur of metal sticking out of the housing or that the inner liner was deformed as you made your cut obstructing the opening of the housing and the path of the inner wire in this case you might need to cut the housing again slightly further down where the coil cuts cleanly or even use a rotary tool with a cutting disc like a dremel to remove the spur once you have a clean cut insert your pointed tool into the inner liner and widen the opening so that the inner wire can pass through without obstruction shift housing cuts the same way you'll recall that shift housing is straight not coiled so there's no problem with Spurs however cutting flattens the opening a lot more than it does with break housing so you'll need to take more care to widen the opening sometimes it even helps to pinch the outer plastic sleeve back into shape step 3 lubricating the housing some mechanics don't lube cables because they believe that the inner liner of the housing is slick enough and that Lube will only cause drag and slow the inner wire down however because it's fully fluorinated with a higher lubricity than teflon finish line extreme fluoro is slicker than the inner liner and it's low viscosity guarantees that the wire will move into housing without any drag it also provides protection against corrosion for the life of the cable a large part of why you Lube them in the first place to apply it simply insert the tip of the syringe into the opening where you'll be inserting the inner wire and squeeze you don't need much and once you see grease beginning to come out you're done then take a metal ferrule and place it over the end of the housing pushing it down so that it's as tight as possible if you'd like you can place the ferrule between the jaws of your cutter and gently squeeze this is called crimping and leaves an indentation that helps hold the ferrule in place once you've done that all that's left to do is insert the inner wire into the housing as you do so the I will distribute the grease along the length of the housing shift housing is lubricated the same way as brake housing take your finish line extreme flora insert the tip of the syringe into the open end of the housing and squeeze until you see grease begin to come out around the tip then if you're using five millimeter shift housing which is the same diameter as brake housing take a metal ferrule place it on the end of the housing and run the inner wire through many modern shift systems use four millimeter housing which is slightly narrower the only difference here is that once you've lubricated the housing you place an hour or plastic ferrule on the end that's usually already crimped the two sizes are actually interchangeable and many mechanics prefer to use five millimeter housing for added stiffness you