guy153

This is my rear caliper, which is cable-operated. But what's the best way to run the cable for this? Outer cable all the way? From the lever, down the downtube, and under the BB shell? Or over the BB shell? Because that angle is so tight, is it better to run the cable underneath the chainstay rather than on top of it?

Andrew R Stewart 

What conditions will the bike see? IMO the reason to run full length cable housing is for contamination reduction. Otherwise I prefer segmented casing sections.

Is the caliper adjusting barrel directly on top of the chainstay or offset to one side a bit? If directly on top and the resulting casing bend being really tight I might look at pulley methods to route the cable out of the caliper and along the stay's top. If offset a bit I would consider having the casing below the stay, passing by it along the way up to the adjuster. Andy

dsaul

I run them on the top of the stay and always use full length compressionless brake housing. Running a 160 rotor on the rear gave me a bit more clearance for the bend and better stopping power.

Andrew R Stewart 

I note that dsaul's caliper is mounted about 10-20 degrees clockwise compared to guy's. The entry angle of the cable need less bend and the adjuster is higher up off the stay too. As I look at guy's caliper mount/dropout it looks like the mount was added to the dropout and the top of the chainstay filed a tad for a flat fit. If careful cable routing doesn't work out perhaps a custom adapter plate that moves the caliper up, back and rotates it a tad too could be made. But I would experiment with a test cable and zip ties first.

Does the cable run have another adjuster, other than the caliper located one? Using a simple casing end cap (that has a snout that would enter the adjuster threaded hole) might get you a few mms of added clearance. Have you tried a V brake noodle? There are various angles of curve as well as flexible types. I also thought about a pulley type of thing but thick cables running around a pulley tend to add more lever pull slop feel. Andy

guy153

Yes I think my flat mount is less "flat" than dsaul's. I made it by modifying a post-mount dropout (described in this earlier thread):

https://www.bikeforums.net/23086583-post16.html

But basically the casting I have slopes up a bit more, creating the issue. Possibly also because it's QR rather than thru-axle.

I have the DR03 from here. dsaul's looks similar to the DR06:

https://www.framebuilding.com/NEWPAR...20Dropouts.htm

Also dsaul has an adaptor there for his 160mm rotor that raises the caliper up a bit. My rotors are 140mm (not about to change those

The cable stop seems to be aiming slightly at the inside of the CS. So it's possible that I want to run a bit of outer inside the CS and then along the bottom of it. Then maybe I put a cable stop a few inches in on the bottom of the CS (just like the one that's on the other side for the rear derailleur), run bare cable under the BB shell if it will fit with the gear cables (or perhaps route it above if not) to another cable stop somewhere. I will experiment tomorrow also with the wheel in there to check how things fit.

Slightly tempting to run a bit of 3/16 pipe through the CS and out of the bottom, having just watched Paul Brodie's "Mantis stem" video But I don't think this is really a good idea.

Although this is a "gravel" bike I expect it to be mainly ridden in the quiet countryside around Berlin and I'm going to be running the gear cables in segmented sections anyway.

unterhausen

To me, it looks like your adjuster is drooping a bit. If that's not true, did they drill the hole crooked?

Andrew R Stewart 

"The cable stop seems to be aiming slightly at the inside of the CS. So it's possible that I want to run a bit of outer inside the CS and then along the bottom of it. Then maybe I put a cable stop a few inches in on the bottom of the CS (just like the one that's on the other side for the rear derailleur), run bare cable under the BB shell if it will fit with the gear cables (or perhaps route it above if not) to another cable stop somewhere. I will experiment tomorrow also with the wheel in there to check how things fit." guy153

That's pretty much what I did but my use of a SS tube was for the BB "corner". Here's the link to that short thread Grovel Bike Done - Bike Forums It has some photos showing my cable routing solutions. For this bike's replacement (which I'm close to completing the torch work) I will mimic the cable routing with tiny tweaks here and there. Andy

guy153

That seems to be the solution I'm converging on. I had one of those plastic things but it doesn't seem to fit very well so I'm using these "cable tunnel" things (ART 146 and 144) which I already have a few of left over from a previous project for all the cables.

Running some outer from the caliper under the CS looks like it fits pretty well with no extreme bends. The main thing is to make sure the cable for that rear caliper doesn't foul on the two gear cables. I might run the outer over the BB shell instead to a cable stop on the DT instead as it's a bit crowded under the shell.

Brazeons