# Brake line length?



## Dropout33 (Apr 9, 2007)

How do you determine what length you need? For example I am looking at a set of Hydros that come pre-bled with 1300mm rear and 750mm front hoses. How do i know if these will fit?


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## HamfisT (Mar 31, 2010)

Use an old housing, or a piece of solid core copper wire (house wire), as a mockup, then measure that.


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## Dropout33 (Apr 9, 2007)

Problem is this is for a build that I am getting parts together for. So I cant mock it up yet.


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## oldskoolbiker (Jun 2, 2005)

1300 / 750 is really short. I bought a set that was 1500 / 750 and the 750 was barely long enough for a rigid fork. Also I'd say 1300 will be cutting it close for the rear unless it's a small bike. 

Your typical mtn bike you probably need like 1500 / 900 at least.


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## jeffgre_6163 (Jan 23, 2010)

oldskoolbiker said:


> 1300 / 750 is really short. I bought a set that was 1500 / 750 and the 750 was barely long enough for a rigid fork. Also I'd say 1300 will be cutting it close for the rear unless it's a small bike.
> 
> Your typical mtn bike you probably need like 1500 / 900 at least.


Yeah - what he said


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## Alun_buildyourbicycle (Apr 13, 2010)

oldskoolbiker said:


> 1300 / 750 is really short. I bought a set that was 1500 / 750 and the 750 was barely long enough for a rigid fork. Also I'd say 1300 will be cutting it close for the rear unless it's a small bike.
> 
> Your typical mtn bike you probably need like 1500 / 900 at least.


Agreed.

Would even go further and say that 900 is too short for a 5-6" fork.

The best option is to buy 4metres of uncut hose, some decent cable cutters, and do it yourself


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## oldskoolbiker (Jun 2, 2005)

I just measured mine on my FS rig and it was 1475mm for the rear, and 825mm for the front. The frame is a size medium 575 with the cable routed down the down tube and across the chain stay. The front has a 150mm fork However I cut my lines so there is pretty much no excess. Also I measured my line on my DH bike with a 8" fork, and it was 865mm.


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## jonw9 (Jun 29, 2009)

Bump an old thread.

I am trimming the lines on my Hayes tonight, and I am trying to figure out how much to cut.

The front should be a non-issue since there is no "pull on the line, so I was going to make it just long enough to lay along the fork nicley.

The rear is a different story. Should I crank the bars 90 degrees right, and hav enough cable for that, or is there a better method. This would only be an issue in the event of an unexpected dismount. Should I make the line shorter so if this were to happen, the line will be the thing that stops the bars from rotating too far?

Suggestions/pics would be appreciated.


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## b-kul (Sep 20, 2009)

jonw9 said:


> Should I crank the bars 90 degrees right, and hav enough cable for that,


this is how ive always sized cables. might be a better way but this works fine.


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## jerry68 (Aug 23, 2007)

Pre-bled brake sets are great, but eventually your going to need to learn how to bleed them, as brake fluid does wear out.


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## Crosstown Stew (Aug 16, 2008)

Yeah, 90 degree test is what I was taught and always gone with. Better to be a little long than rip out while on the trail after an ugly crash.


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## jacktro (Aug 3, 2010)

a few weeks ago i fitted a set of avid elixer5 that came pre bleed and had to cut of a massive 540mm off the rear and 250mm off the front...had to triple check my lengths just to be safe but tuned out fine....so i guess you never really know what length you'll get with pre-bleed hoses but longer is way better than shorter..


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