General Cycling Discussion - Cables in or out of housings?

This question applies to both deraileur and brake cables.

What are the rationalizations/reasons for using cable stops and running the cable in the open atmosphere?

Pro
Less friction
Cool Braze on attachments
less weight?

Con
Allows more dirt in (2x? or more?)
less weight?

I am not sure what weighs more: the braze on hardware vs. the amount of housing removed.

I saw a tandem with three cables in the open across the top tube. They had a cable stop in front of and behind the capatain's seat post, and the cable here was bent enough to cause more than nominal frictions. Then they were bare again all the way to the cable stop at the stoker's seat tube.

With today's teflon coated cables n such, wouldn't 100% housing be more reliable?

I would think that would still be too much friction. :)

For road bikes, almost everyone has now settled on full cabling for brakes and open cabling for derailleurs. With proper maintenance and lubrication, it probably does not make much difference. Full cable housings with downtube or stem shifters never did work well, because water tended to drip down into the housing.

I use full housing on my brakes, on all-weather bikes.
Dearilleurs are much more critical in terms of the amount of cable pull, and the slight variation caused as extended housing moves would screw up indexing.
Beware of gear cables running down the seat-stay. The small section of cable at the bottom is open at the top to water, but there is no escape for water at the bottom of the loop.
Ive had problems with gear cable guides under my BB. 2 small eyelet style tabs put a slight king into the cable run, whcih wears out a cable prematurely. A fuly shaped cable guide is much better.

I think it's mostly a matter of aesthetics.

A full cable housing is bulkier than a nude cable; besides, it is never totally straight.

P.S. My 1980 touring bike has full brake cable housings, but exposed derailleur cables, and my 2000 touring bike has exposed brake and derailleur cables.

I also remember that my 1974 10-speed bike had fully enclosed brakes and derailleur cables. Shifting wasn't bad for the period(pure friction), but the shifters were twice longer than modern downtube shifters. I also broke one or two derailleur cables per year. Now, I break almost none.


Another aesthetical point: they used to make housings in many colours that could -- almost -- match the frame paint. Now, there seems to be only black, white, and a few fluorescent colours. It's impossible, for example to find mid-beige or deep blue housings to match the colour of my 1980 or 2000 bike, for example.

Regards,

The reason to use stops with bare cables, was to avoid compression of the cable housing. The frame is less compressible than the housing so when the cable is put under tension, the max precision is achieved in the amount of movement at the far end of the cable. The spirally wound housings compressed a lot more than the newer ones which have the strands going the length of the housing.