wernst

All,

So I'm re-cabling my 80's era MTB with new Jagwire cables today. I'm to the point where you are supposed to connect the Sealing Liners with the cable-stops-with-those-straws-sticking-out, but I'm looking at the brazed on cable-guides on the top of the bottom bracket. Here's a photo:



I'm thinking there's no point of using the sealing liners because of the braze-on cable guides (wouldn't the cable just eventually cut through the Sealing Liner through use?), but maybe the collective experience of the forum knows that the Sealing Guides are just perfect for this application.

Any advice? Ideally so I can finish this up later today?

Thanks,
Warr

FBinNY 

If the guides have a good "fair lead" to the wire at both ends, meaning they lead the wire out in line than nothing is needed, though many slip a piece of teflon tubing in hoping to reduce friction.

OTOH your front guide (with the cable threaded in the photo) doesn't appear to have a fair lead, and the wire makes a bend where it enters. This increases friction, and will lead to fatigue, fraying and breakage with use owing to the bend. I'd stick in a piece or relatively stiff tubing hoping it'll broaden the bend, but there's no guaranty that it will.

BTW- my comments baout poor lead on your fitting are based only on the photo, and it may be better than it looks.

dddd

Adding any liner tubing is problematic as the tubing usually doesn't settle into the guide and so may drift about, eventually leading to a loss of cable tension if the tubing moves out of the guide. This is fatal to indexing shift quality, but not such a big deal with a friction shifter.

And yes, cables tend to rub through plastic liner tubing, and tubing tends to collect silt and water.

I run these bb cable guides bare, even for use with STI and Ergo shifters. I lube the guide whenever I lube my chain.

Burton

Yeah - normally those cable guides and the plastic guides that run under the BB are expected to be greased and run with bare cables. Regardless - I can't see any issues with extracting the teflon tubing from a brake noodle and using that through the guide. It's common practice with guides for canti brakes and you can probably squeese the plastic cable sheathing over it for a good seal.

I don't really agree that sheathing is problamatic. Riding in conditions that call for sheathing and ignoring increased maintenaince requirements is the usual cause of cable issues. If reduced maintenaince is the objective - full housing runs are hard to beat.

fietsbob

Nobody makes over the BB shell cable runs anymore, on bikes, might as well just run the bare wire through.

maybe make a small brass liner for the cable guide, brass is softer than steel .