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(Please see edit below; problem might actually be with brake lever)

I'd like to know if a temporary resolution is possible for my stuck rear brake cable.

From https://drive.google.com/file/d/1JceR28W6Pot9i5v5Y_v3WtEV49UXqhvD/view?usp=sharing

Video: https://drive.google.com/file/d/1EmGB78BphkK4k27j4BNouMpIK31A31ST/view?usp=sharing

I'm taking it into the shop but the soonest they can take my bike is Tuesday. I have no experience in bicycle repair. The bike is only half a year old, but I've been riding it in winter. I clean the brakes (excluding the pads) every one or two weeks with a soft bottle brush and diluted dish soap. I have never lubricated any brake parts yet, though.

Edit: I might have been wrong on the location of the malfunction. The brake lever seemed stuck, and I assumed that was because the brake was stuck, but after squeezing it very hard it seems to work to some extent. It makes a creaking noise and doesn't move as freely or with as much range as the front brake.

Edit 2: The problem was the cable or housing, not the brake lever.

  • Yeah, probably the cable is gummed up. Sometimes this is due to rust/dirt in the housing, sometimes due to a bad kink in the housing, sometimes due to simply having the cable misrouted. – Daniel R Hicks Mar 2 '19 at 20:24
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    Has anyone noticed the cable is rusted to hell? It’s approaching a tomato red color and this would cause massive friction imho – Swifty Mar 2 '19 at 20:31
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    I've shrunk and brightened the image, and then added it in-line. Can't do anything to inline the video link though. If it were uploaded to youtube then inlining is possible. – Criggie Mar 2 '19 at 22:28
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    I'll note that the cable lube I prefer for recalcitrant cables is a Teflon-based lube such as Tri-Flow. WD-40 isn't anywhere near what you need. – Daniel R Hicks Mar 2 '19 at 23:10
  • The principle law of engineering commands the use of WD40 here. – Peter - Reinstate Monica Mar 3 '19 at 16:53
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As others have said, looks like rust/corrosion increasing friction.

To repair teporarily You could try dripping some solvent and lubricant onto the inner cable so it weeps up into the outer. This might get it moving slightly better, but is not really a fix.


To Repair PROPERLY: replace the inner cable completely, and depending on the condition the outer sheathe too. This is not too hard and can be done by the home mechanic.

You'll need a replacement inner cable with the right mushroom head. Look inside your brake lever to see what the end looks like. I'd be 99% sure its a MTB or off-road design, which is a cylinder shape with the wire coming out the curved side (right in image). The road one is a double cylinder with the wire coming out the centerline vertically. (left in image)

enter image description here

You simply undo the retaining bolt/nut at the brake, feed the wire out, undo from brake lever, and then Haynes it back in.

If the new cable is hard to get through the old outer, you might have corrosion or wear in there too.

A kit with enough to do a whole bike is less then the cost of lunch, and will contain two inners and enough housing to do the lot. Example:

https://www.wiggle.co.nz/lifeline-essential-brake-cable-set-mtbhybrid-1/

As for tools a cable cutter would be nice, but not required. Trimming the excess inner can be hard - check the answer at How to cut a brake/derailleur cable? for tips and techniques there.


Prevention I can't see in your video or image, but rust is caused by water and aggravated by salt. So keep your bike dry and wash off any road salt after wet rides. Also helps if your bike is stored in the warm and dry overnight. Outside in the rain will certainly accelerate rust.

It is possible your rear brake is poorly routed too. If the lowest point is not an end then water will pool inside the cable. If this is the case consider rerouting the cable on the frame, perhaps up the chainstay. You can also use longer lengths of outer housing and skip some of the frame stops. Water can't get through the outer housing, it only goes in the ends.

Another thought is to protect the end of the cable better. You could possibly put a squirt of marine grease up the outer before fitting the inner. This should provide some level of seal to reduce water ingress, but it reduces water egress too.

Last thought, a V brake noodle-boot may provide additional coverage if threadded over the inner, where it exits the outer down by the caliper. I'm talking about the black rubbery bit here - (its only half the cost of lunch)

https://www.wiggle.co.nz/lifeline-v-brake-guide-pipe-with-boot/

All this is within reach of the home spanner wielder. Any questions do ask here or check in [chat]

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    Regarding the brake noodle rubber: I’ve always wondered if it might actually make matters worse by trapping dirt. – Michael Mar 3 '19 at 8:29
  • @Michael fair thought - but we use them for this exact purpose on the exposed inners of V brakes, which are right over the dirty tyre and suffer from water and dirt exposure. – Criggie Mar 3 '19 at 12:29
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    The problem was indeed the cable and/or housing. Thanks. I'm riding on lots of road salt. I clean the bike with (dish) soapy water every week or two, but either that's not enough or it was a critical failure to not re-oil the exposed part of the brake cable after cleaning salt from it. I don't think it's realistic, in my case, to wash the bike after every ride. I realize that means increased wear on the bike. I'll have to learn how to inspect my bike for signs of impending failure. – Ranen Ghosh Mar 5 '19 at 1:42
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From the video, it looks like the cable has frayed inside the outer housing or something like that. I doubt there's anything you can do except get the bike shop to replace the cable.

Although most of the braking comes from the front brake, I woudln't recommend riding the bike in this state: you'd have no back-up if anything went wrong with the front brake.

  • I might have been wrong on the location of the malfunction. The brake lever seemed stuck, and I assumed that was because the brake was stuck, but after squeezing it very hard it seems to work to some extent. It makes a creaking noise and doesn't move as freely or with as much range as the front brake. – Ranen Ghosh Mar 2 '19 at 19:47
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    +1 for suggesting to not ride without braking contingency. – Swifty Mar 2 '19 at 20:28
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    Are you really always braking early and softly enough that the rear brake alone would be enough to stop you? For fast, accurate braking you need the front brake. The rear brake won’t safe you. In the unlikely case that the front brake fails you’ll crash, but that’s also true for a lot of other components (e.g. handlebars). – Michael Mar 2 '19 at 21:59
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    @Michael You're only thinking about "external" emergencies but brake failures can cause emergencies in situations that would otherwise be safe. Suppose you're going down a hill that's not very steep, controlling your speed with your brakes. If your front brake fails, you can still use the rear brake to bring yourself to a controlled stop. With no brakes at all, you have no safe way to stop. Even in an external emergency, I'd much rather have a rear brake than no brakes at all: sure, I'm not going to be able to perform an emergency stop but I'll be able to scrub off some speed. – David Richerby Mar 2 '19 at 22:12
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In addition, that cable looks dirty to me in the picture and video. Maybe it's just the lighting? But if you have anything like WD-40, you can spray it on the cable and see if it loosens up. It's worth trying as it won't hurt anything.

If water gets into the cable housing when you're cleaning the bike, something like this could happen as the insides of the cable might rust up.

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Looks like excessive friction between cable and cable housing. Probably caused by a frayed cable or a kink in the housing. Is the cable housing damaged somewhere?

I’d try unclamping the cable at the brake and then check if the brake moves freely. You can then also unhook the cable at the brake lever and check if it moves freely as well. This would prove that the cable (or its housing) is the culprit. Light, penetrating oil (e.g. WD-40) could temporarily help to get it moving again, but if it’s damaged it could fail completely at any moment.

You could replace the cable yourself, it’s quite easy. Replacing the housing is a bit harder and works best with special tools. It’s a bit easier if you are only replacing it since you already know where it should go and how long it has to be.

Riding without a rear brake is relatively safe (as long as the front brake works properly). Just make sure you remember that you don’t have a working rear brake, especially when indicating a left turn (assuming your rear brake is on your right hand).

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    Note that riding without means of stopping the rear wheel would be illegal in certain countries because it’s a bad idea – Swifty Mar 2 '19 at 20:29
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    When the rear brake looks as bad as this the front brake might be not far from malfunction either. – gschenk Mar 2 '19 at 21:42
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    I disagree with your last paragraph, but all the rest is spot-on. – Criggie Mar 2 '19 at 22:30
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    Thanks for the help. I tried unclamping the cable at the brake: brake actuator on the brake moves freely but brake lever at the handle does not. I then unhooked the cable at the brake lever; the brake lever then moved freely. So the cable or housing are the culprint. – Ranen Ghosh Mar 5 '19 at 1:36
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    @RanenGhosh: Thanks for the confirmation. You could change to hydraulic brakes (+levers) to avoid this problem completely in the future. – Michael Mar 5 '19 at 9:41

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