I took my wife’s back wheel apart yesterday to check the bearings. I cleaned out the free wheel body in the process, cleaned everything, lubed the proper surfaces and put everything back together. That took about fifteen minutes – and the bearings in her Ican wheels are still fast, tip-top and silky smooth after several years of everything she could throw at them.
After putting the rear wheel back in the dropouts, I instinctively gave the brakes a squeeze (I always do this to see how the brakes feel). The front brake was fantastic. The rear felt gritty and sluggish. The cause is typically dirt in the system somewhere that makes the pull on the lever seem sluggish and harder than it should be.
Now, I’m talking about an internally routed cable here, so to the budding mechanic, this might seem it isn’t a simple fix. Unless you know the shortcut: cable liner. Not cable housing, cable liner.
Loosen the screw that holds the brake cable to the brake caliper. Use a pair of toothless pliers to remove the cable end cap, then pull out the rear housing. At this point, for internally routed rear brakes, you should have a bare cable. Thread the cable into a piece of cable liner that’s long enough to come out the front hole of the frame. Once the liner is through the frame, you won’t have to worry about trying to thread the cable through the frame (btw, if you run into a problem, say you accidentally pull the housing out of one of the holes, use a magnet to thread the new cable through the frame).
Once you’ve got the cable exposed at the front of the bike, depress the brake lever and pull the cable out of the hood, but not all the way out. I like to leave an inch exposed from the end of the housing. Now, clean everything of dirt and debris. Cable ends, cable stops (the stops are the thing that the cable housings “stop” at where the cable enters the frame), clean everything. Then, depending on the weather you’ll be riding in, my wife’s bike is her warm weather bike, pick a lube to suit the conditions – a light spray lube for cold weather, a heavier lube for warm (because the more viscous lube will tighten up in the cold – for warm weather I like Finish Line Ceramic Wet Lube… that $#!+ is slippy) and lube the cable. Pull the cable back through the housing, reroute it through the liner and reconnect the cable end to the brake caliper. Set your brakes and you’re done.
To finish this up, give the brakes a test squeeze. If that holds, give it a fairly tight squeeze to make sure everything was seated properly. Check the where the cable goes into and exits the frame to make sure the cable ends are seated properly. If all is well, that’ll do.
Now, this isn’t a permanent fix. It’ll last a season. After you’ve lubed the cable a time or two, though, it’ll be time to change the housings and cables.