How difficult is it to replace front disc brake cable housing?

cpml123

Zen MBB Master
Hi all,

I am interested to replace my S40's front disc brake cable housing to Jagwire compressionless housing. I am just wondering how difficult and how long it take to do that.

I have been working from home. I can drive to work and pay the on-site bike shop about $40 to do it. So my cost would be almost 2 hours commute plus $40. Or I can buy the Jagwire cutter and whatever tools and spend my time at home figuring out how to change the brake housing.

Any suggestions? Thanks.
 

Rod Butler

Well-Known Member
Hi all,

I am interested to replace my S40's front disc brake cable housing to Jagwire compressionless housing. I am just wondering how difficult and how long it take to do that.

I have been working from home. I can drive to work and pay the on-site bike shop about $40 to do it. So my cost would be almost 2 hours commute plus $40. Or I can buy the Jagwire cutter and whatever tools and spend my time at home figuring out how to change the brake housing.

Any suggestions? Thanks.


A cable cutter is always a good investment,
just remember to retract the actual cable when you cut the housing.
An old trap for young players, we've all been there!
 

Frito Bandito

Zen MBB Master
A cable cutter is always a good investment,
just remember to retract the actual cable when you cut the housing.
An old trap for young players, we've all been there!
It is embarrassing cutting the actual cable as short as the housing isn't it?

1 trick I learned to keep the internal part of the cable housing round on the tail end is to pull the cable from the lever end so that it leaves only a couple of inches of the tail end of the cable past the housing cut point on the brake pad side. That way, when you cut the cable, you only lose a couple of inches of it, and it is a clean cut leaving the internal part round so the cable slides through it easily. Without any cable inside while you cut it often results in the cable housing not being round after the cut.
 

benphyr

Guru-me-not
+1 It is easy. +1 on watch YouTube

Tips:

Use the old housing piece(s) as templates to measure how long to cut the new housing.

And if you end up with the housing a bit squished then use an awl or little round screwdriver to open it up again.

A sanding block or bench grinder can take down any sharp edges and/or smooth the cut to perpendicular.
 

DavidCH

In thought; expanding the paradigm of traversity
It is embarrassing cutting the actual cable as short as the housing isn't it?

1 trick I learned to keep the internal part of the cable housing round on the tail end is to pull the cable from the lever end so that it leaves only a couple of inches of the tail end of the cable past the housing cut point on the brake pad side. That way, when you cut the cable, you only lose a couple of inches of it, and it is a clean cut leaving the internal part round so the cable slides through it easily. Without any cable inside while you cut it often results in the cable housing not being round after the cut.
Yep... you don't get caught twice... I have an irritating front derailleur cable issue on my df. The cables are so friggin tight that it pulls the front cable after a month of use. The bike has been designed for di2 or wireless. Next time around I will use compression jagwire housing. Its really the best with the twist and turns.
 
If you want a challenge, try feeding a rear brake hydraulic hose from the caliper through the frame and out the front hole. It requires a fair amount of cussing.
 

Frito Bandito

Zen MBB Master
Yep... you don't get caught twice... I have an irritating front derailleur cable issue on my df. The cables are so friggin tight that it pulls the front cable after a month of use. The bike has been designed for di2 or wireless. Next time around I will use compression jagwire housing. Its really the best with the twist and turns.
I didn't notice it the first time I strung up my DF bike, but the 2nd time I noticed that the shifter cables were thinner than the brake cables. So far I haven't needed to try it, but I bet the thinner shifter cable will work as brake cables in a pinch. They might need replacing sooner though.
 

cpml123

Zen MBB Master
I just ordered the Jagwire housing cutter. I guess if I can do it in less than 2 hours, I come out ahead. :)
I just did it today. Finished in about 1.5 hours, so a little ahead than driving to work. Plus I figured out I could use the leftover Jagwire housing from the rear brake job done by the LBS instead of using a new set. Saves another $33! I tested it out... it works! :) I did pump the brake many times to stretch the cable.

Front Jagwire housing doesn't seem to be as noticeable of a brake performance difference as the rear brake. I guess the rear one is much longer.
 

Frito Bandito

Zen MBB Master
Nice going CPML. The next time will be faster, and if you ever need to maintain them it will be easy. I will be swapping the Shimano Claris 2x8 system on my commuter to a Tiagra 4700 2x10 system this afternoon. I will keep the OEM 50/34 cranks the same for now, but will swap them for some new ones once I find the crankset I want.
 

jond

Zen MBB Master
I didn't notice it the first time I strung up my DF bike, but the 2nd time I noticed that the shifter cables were thinner than the brake cables. So far I haven't needed to try it, but I bet the thinner shifter cable will work as brake cables in a pinch. They might need replacing sooner though.

no it won’t. That would be very dangerous.

Mechanical Brake and shifter outers are wound differently. Brake outers require them to be capable of withstanding a lot more force.

As such brake cable will pull through shifter cable outers due to its longitudinal wired casing.

Brake outers are wound cylindrically across the cable itself. This gives a lot of strength.

at least that is what I understand the last time I built a bike with the jag wire and shimano outers I used.

you can see the difference when you cut gear cable outer you can see multiple ends of cable reinforcement. Versus the brake cable which is one one cylindrical coil.
 
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Frito Bandito

Zen MBB Master
That is good to know Jond. I think I have a mixed bag of Jagwire and Shimano brake wires now simply because I have switched from Tiagra 10s to 105 11s, from the original DB wheels to rim brake, and changed the position of the rear brake from the top mount to the bottom mount so often while fine tuning the fit that I had to salvage or buy individual parts. But now that I know where I like everything, if I buy new disc brake wheels then I will go with a full set from either so there isn't any risk. When those multi-day trips start rolling around then I will carry spare wires in the moose pack.
 

jond

Zen MBB Master
That is good to know Jond. I think I have a mixed bag of Jagwire and Shimano brake wires now simply because I have switched from Tiagra 10s to 105 11s, from the original DB wheels to rim brake, and changed the position of the rear brake from the top mount to the bottom mount so often while fine tuning the fit that I had to salvage or buy individual parts. But now that I know where I like everything, if I buy new disc brake wheels then I will go with a full set from either so there isn't any risk. When those multi-day trips start rolling around then I will carry spare wires in the moose pack.

Sorry frito to be clear there is no risk mix matching brake cable outers from different manufacturers. As far as I am aware. I’ve used shimano and jag wire only.

I edited my last post to be clearer.

There is a serious risk of using gear outer cable as a brake outer. As the actual brake cable will pull through the actual outer rendering the brake inoperable.

we already have a no brakes here on the forum ;)
 

Frito Bandito

Zen MBB Master
Sorry frito to be clear there is no risk mix matching brake cable outers from different manufacturers. As far as I am aware. I’ve used shimano and jag wire only.

I edited my last post to be clearer.

There is a serious risk of using gear outer cable as a brake outer. As the actual brake cable will pull through the actual outer rendering the brake inoperable.

we already have a no brakes here on the forum ;)
Ah, I think I was the one who was unclear braddah. Without going back I believe I meant using a gear inner on the brake outer. If I didn't write that then that is what I was thinking. Until this moment I wasn't even considering a "thicker brake inner with a thinner gear outer." Talk about a tongue twister :D
 

benphyr

Guru-me-not
You would need to be aware that your brakes would not operate nearly as well because the gear cable is thinner and not as strong and so it could much more easily snap from the increased tension of braking vs. shifting. Also the cable would be able to move within the housing a little making it less predictable.
 
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