how much is too much? (cable outers)

[jax13]

I always tend to cut my outers to length by a simple trial & error after an initial mock-up to get a ball park length but is there a magic formula or measurement that will give you the optimum length or is it simply mock-up and cut where it looks right?

 

[Carlos]

Yep, there's a formula...

It's the distance between A and B, plus some slack. Perfect every time

 

[mechagouki]

Enough that you can turn the bars so they are parallel to the top tube without your cables binding on the head tube.

 

[FluffyChicken]

It is as you say, take a guess and then adjust if needed. Remembering these modern ferrules often take up a good distance in themselves.

Lines should be neat, and preferably with no double bend in them, they should enter the stop/barrel in-line, not at an angle. (often seen in rear mechs when people try to make it too short or don't cut it down)

Each to their own with the handlebar cables, I try to do it as they say above, but to be honest if shorter works better then I'll use that. I don't often ride my bike with the bars beyond 90degrees (or near that, but cables can start to pull before then if too short ...), so for me after that is doesn't matter if the brakes are pulled or the gears will change.

For some bikes it may well be a compromise and cables will need to use a different style of setup.

 

[petitpal]

I tend to keep them as short and neat as possible but always bearing in mind the route that the cable inside is going to have to take - that's what the outers are there for, after all. For handle bars I tend to cut them so that the outer allows the bars to move to their maximum sweep (usually ends up to just about touching the tob tube) so that when, sorry if, I crash the cables aren't putting too much strain through stuff. I tend to chuck the outers in without cables and then have a play with the bars (turning both left and right) to see how it looks at the opposite side of the sweep as well. But maybe I just a bit anal.

 

[SeeingisBelievingGTMuseum]

The length of housing from the rear derailler to stay cable stop is very important.

 

[highlandsflyer]

I have to say this is one area of builds I tend to notice, usually too much length is evident.

If the old ones were 'right' use them as a template and run them the same way.

 

[Tazio]

I tend to cut them just the right length for both practicality and looks, then run the inners, terminate them and adjust everything just so.

Then I'll look at them the next day and decide they are too long and by then I can't be arsed taking them off again.

 

[jax13]

the rear mech outer is an interesting one, i've been using a modern x-9 mech for a couple of years now and i have to admit, it does look a lot tidier than the older style as you can run the cable pretty much straight in because of the curved guide on the mech itself. I am also a big fan of rollamajigs if for nothing more than getting rid of the loop to the mech.

its the handlebar to top tube lengths i was more curious about and if there was some magic formula (stem length + distance from shifter clamp to centre of handlebar + 5" = perfect... or something similar) but it would seem eyeballing it then small adjustments seem to be the correct way.

 

[Raging_Bulls]

You also need to account for the height, Jax. I replaced the riser bars on my copperhead with straight bars, and suddenly all the outer cables were too long despite the levers being the same distance from the center of the handlebar.

For me it depends if I have the previous outer cables or not. On my last build they were all knackered and the wrong length to begin with so I tossed them all in the bin and started fron scratch. No maths involved, just by feel and looks.