“No housing? No problem”: Cyclist baffled why brakes no longer work after shocking DIY cable botch job – then complains mechanic charged him too much; Van der Poel returns to racing – but no Strade Bianche, team says + more on the live blog

How true is the wheel though?
You can rotate the wheel to check for any spots where the rim catches the block. As long as you have only one or two places, then careful use of a spoke tool will fix it. However if it is too far out or too many spots, best to take it to a shop otherwise you could easily make it worse

Hub brakes have their own trade-offs.  I actually liked the one I had for its particular application - in a "utility" bike where I didn't care about "speed".  Very infrequent maintenance, it didn't care about rain / road slush / banging the bike.  Maintenance wasn't hard but did involve some dismantling.  With adjustment it was not underpowered e.g. could lock the wheel.

However it was heavy metal and lacked the finesse of e.g. hydraulic discs.  Plus I imagine it would get very hot in the mountains.

Brakes working on rotating surfaces are all the same - if the distance to the surface varies at some point there will be problems.  Brakes at the hub are no different, just less likely to get out of alignment in common situations.  All of 'em need some adjustment at some point.

Disc brakes avoid the perils of wheels getting out of true, but if you bash the rotor it may be stuck wheel - and new rotor time.

It's fine for it to be bare between two points that are fixed in relation to each other and covered by straight lengths of cable, because it will always require the same amount of cable to cover that distance. Where you have parts that move in relation to each other, or an unfixed turn that needs to be made, you need the outer to maintain the distance of the cable run. Otherwise, when you try to apply tension to the cable, the unfixed sections will simply try to straighten out a bit, instead of transmitting it all the way to the other end.

That sounds very old-fashioned!  And pretty rubbish - cables break, stretch, there are losses in the system, it's not digital ... we need to disrupt bike design!  We already have wireless...?

Thanks for the explanation, mdavidford.
Very much appreciated.

Good point!  And why use a flimsy cable when you could have something more substantial?

My wife's "pootle around the village " bike is an old Raleigh with rod brakes. They are NOT fun to play with.

I tried, but I just cannot in earnest believe that this question is sincere.

I'm not really fussed if you believe it was sincere or not.
I'm not a bike mechanic.
Or a physicist.
My technical specialisation does not include mechanical cables.

I am however, unlikely to try this at home based on two reasons:
1. The outer case is there for a reason. Because I don't know what that reason is, doesn't mean I should feck around with it.
2. I have full hydraulic brakes.

In engineering, there was a term that appeared on all drawings: If in doubt - ask.

No-one should ever be belittled, berated or humiliated for asking a question.

Oldfatgit wrote:

2. I have full hydraulic brakes.

Hmm... that might work with a slight modification at the piston end, and low enough temperatures?  (See my pic above)

Oldfatgit wrote:

No-one should ever be belittled, berated or humiliated for asking a question.

Generally agree, unless it's "why should we do anything for cyclists when nobody cycles?" - although it's arguable if that's really a question.

Oldfatgit wrote:

The outer case is there for a reason. Because I don't know what that reason is, doesn't mean I should feck around with it.

This is an important principle that I wish more tech people made use of. It's been called "Chesterton's Fence" (https://fs.blog/chestertons-fence/)

G K Chesterton wrote:

There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, “I don’t see the use of this; let us clear it away.” To which the more intelligent type of reformer will do well to answer: “If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.”

FWIW, I don't think your question was out-of-place or insincere. Something that's obvious to one person may be baffling to another until it's explained.

Thank you Hawkinspeter.

When I've thought about them [which isn't very often], I've only ever considered the sheath to be cosmetic or of low mechanical value - i.e. keeping crap out the inner cable.
I've never considered that they have have had a more important mechanical function ... and now it's been explained, I'll play more attention to their internal lubrication.

Details of the system and why are available on e.g. Bowden Cable on Wikipedia

(There are all kinds of interesting systems for transmitting forces with redirection - see. e.g. rigid chain actuator, Stangenkunst etc.)

I didn't. It's just that for me it is SO logical that I honestly can not fanthom not getting why the houding is needed.
I mean, did you even see how that inner cable is now running? It exits the brake lever at a sharp angle, cutting in to the aluminium barrel adjuster, and hindering a souple movement of the cable. Then it runs through a clip that is meant to keep the housing from moving and potentially rubbing the tire. That clip is very much not built for handling brake forces itself. Then the cable runs diagonally over the suspension fork's leg. Aside from the friction that will add, eventually that cable will eat in to the forks leg.
Every thing in itself should be reason to not want that, but all those things together should be such a clear no go.
Do you actually see the setup in that picture as a viable setup?

Sredlums wrote:

I didn't. It's just that for me it is SO logical that I honestly can not fanthom not getting why the houding is needed.
I mean, did you even see how that inner cable is now running? It exits the brake lever at a sharp angle, cutting in to the aluminium barrel adjuster, and hindering a souple movement of the cable. Then it runs through a clip that is meant to keep the housing from moving and potentially rubbing the tire. That clip is very much not built for handling brake forces itself. Then the cable runs diagonally over the suspension fork's leg. Aside from the friction that will add, eventually that cable will eat in to the forks leg.
Every thing in itself should be reason to not want that, but all those things together should be such a clear no go.
Do you actually see the setup in that picture as a viable setup?

Different people see the world in different ways.

I'd be more inclined to view something in similar ways to yourself - how is it supposed to work - where's the force being applied etc.

However, someone else may come along and start questioning why I'm wearing blue socks with beige trousers and who on earth would imagine that those colours go together. Colour matching/composition is something that's just not on my radar.

Agreed, and to be clear, I don't expect everybody to be an expert in everything (I certainly am not). Ha, I worked at bike shops long enough to know for a fact that many people are not mechanically inclined :-P
It's just that yes, I am still surprised everytime someone doesn't seem to grasp even the most basic pinciples. I am not judging it, but I am baffled. I mean, how can that setup ever work on a suspension fork that moves up and down?

Oldfatgit wrote:

I am however, unlikely to try this at home... I have full hydraulic brakes.

Just think of the weight savings you could achieve there though, because they usually have outers for the whole run!

In seriousness I am also not mechanically minded, and asked the same question in a bike maintenance workshop once.  

It'd work in a straight line but I am not sure I'd like a brake cable exposed to the environment more than it needs to be.

Bigtwin wrote:

absolutetly jaw-dropping.

Literally, when you end up skating along the ground on it.

While I don't think "councillors are crooked from top to bottom" (per some comments you see here) the exceptions are sometime ... exceptional.  And if you are unlucky enough to cross the wrong one there may be a lot of unfairness coming your way.

(I'm thinking of some of the unbelievable - but apparently true - stuff in Private Eye's "Rotten Boroughs" page.  Plus a comment by the late Simon Hoggart which I can't recall exactly but was something like "once you've witnessed local government up close you'll be baying for more centralisation".)

chrisonabike wrote:

Plus a comment by the late Simon Hoggart which I can't recall exactly but was something like "once you've witnessed local government up close you'll be baying for more centralisation".

And vice-versa.  Boris, Truss, Cameron: shining examples of honesty, morals and efficiency.