A funny story. We were at campus unloading my son's stuff from my truck for the first time and I was talking to him about being safe riding his bike on campus.

As we were talking, a student rode right by us talking on his iPhone. Just as I was telling my son not to do that, the student missed the sidewalk ramp and hit the curb next to it and went over the handlebars, rolled and ended up on his feet still talking. Front wheel was toast.

It was the perfect visual aid.

Read the name,i.e. "stainLESS", NOT "stainPROOF". SS will eventually rust. It just takes longer than galvanized steel.
Jon

I work with stainless every day in chemical plants. I've seen stainless develop a rust colored stain on the surface but have never seen it rust like steel (pitting, flaking, etc). The only time I've seen it eaten away was due to chemical attack or water hammer. It could be because we only use 304 or 316 however.

All of my good ideas only apply to bike use at smaller colleges. Sorry

info time... looks like it's needed... someone actually thinks that iron is ADDED to stainless... umm.... and the Nickel is added to promote better machining characteristics, not to limit corrosion... etc... chromium is the key to limiting corrosion... if eliminates oxidation past the very top of the material, thereby preventing rust... and 304 is SPENDY stuff.... 304...
https://connecteddiscourse.files.wor...tion.png?w=640

316 stainless is even more expensive, and has molybdenum added for improved strength...

the stuff used for bike cables is a lower grade, most likely containing zero nickel... 200 series... no machining required, and nickel is REALLY spendy!
https://www.tradekeyindia.com/Pimages...9bcf7feea351df

any "rust" found on a SS cable is surface buildup from cheap cable housings...the crystals grow into the areas between the strands, FROM the cable housings... or the seller lied about the cables....... imagine that, eh? the 15%+ chromium in the SS prevents oxidation of the iron, which is over 75% content in the 200 series steels... steel is mostly iron.... and i'm still chuckling about someone thinking there is copper in SS...

Since stainless is an alloy...or solid solution..., it doesn't matter if you say that iron is added to the alloying agents or the alloying agents are added to the iron. Po-ta-to, po-tay-to. Chromium is added to limit corrosion but so is nickel and molybdenum. The nickel helps with machining but it also provides more corrosion resistance. If you start with nickel and add chromium, iron, molybdenum and some other stuff, you end up with a material that is far more resistant to corrosion...and is far more expensive.

304 isn't all that expensive.

...and for improved corrosion resistance. As is nickel.

Stainless will rust in the presence of chlorides which can come from a variety of sources. I wouldn't assume that a rusted stainless cable is only from the housing without considering other factors.

yikes. A lot of opinions. cycocommute's note is cogent and (at least for this PhD Chemical Engineer) correct. As far as proscriptions and recommendations, Bill Kapaun is spot on. I just stripped my old Schwinn Paramount and the brake and derailleur cables were absolutely fine where they were inside a cable housing. Pretty good outside, too, as I did coat them with grease. (As an aside, I think that they're reusable: they came off a 26 inch frame!).

Regarding stainless rusting. There are many grades of stainless, as is pointed out. The major division is between ferritic (non-hardenable, weakly magnetic, strong, and listed in the 400 series: 409, 410, and others), martensitic (hardenable, weakly magnetic, not as strong, but can be given an edge, also in the 400 series, e.g. 410 and 420, often used in knives), and austenitic ( non-magnetic, and much more resistant to corrosion and rust, labeled as the 300 series, including 302, 304, 304L, 308, 316 and so forth).

Generally, uncontaminated 300 austenitic series won't rust, and won't spontaneously deplete in chromium or nickel. In salt water applications they can fall subject to something called stress chloride corrosion and cracking. (Which is why, btw, you should heat your pasta water first, then add salt to the boiling water and stir so that it dissolves quickly and you don't have salt crystals laying on the bottom of your ss pan as it heats). But no bike that's not a submarine or on board a naval vessel will likely see that. The Bowden cables (which is what our brake and shift cables are called generically: twisted wire with a cast metal end) are often made with 316ss, and this is more resistant to the chloride attack than other 300 series stuff.

Ferritic and martensitic steels rust less than carbon steel, and are more resistant to corrosion. But they will rust. I think most cables that are SS will be 300 series.

Stainless can be considered both rustproof and rust resistant depending on your outlook.

There are many alloys that are virtually rust proof under normal land based conditions. Rain, snow, UV, air pollution, etc. will, not cause rust in both the short and long term. What makes them rust proof isn't consumed any more than your skin is. However, the right conditions, ie. chlorides, or other chemicals, contamination of the surface with other materials including iron, or other not normal conditions can make these vulnerable to corrosion, some of which may be rust, some not but equally destructive.

So, your bike cables or spokes may be fine and rustproof on a bike, but only rust resistant if the same alloys were used on a ship.

By way of example, I have bikes in Cozumel, a place with one of the most chemically destructive atmospheres.

So, both bikes had stainless steel spokes originally, and within 2 years both had the spokes compromised by chlorides, and as brittle as uncooked spaghetti. I chalked the damage to spokes that were improperly "passivated" and rebuilt all 4 wheels with new spokes. That was over 10 years ago, and there's no hint of problems. At the same time, all the original cables, both stainless and galvanized (zinc plated) are OK also, though the stainless ones still look new, and the galvanized ones are almost black.

what grade of SS are they made of.

The simple answer to the question is to get a stainless steel inner cable set for brakes and shifter, along with something like upper level Shimano MTB outers and fit them, lubricated with silicon grease, the type used on rubber seals for swimming pool pumps. If you look at MTB cable sets, you probably can get them with outer-cable ends with extended nipples on them. I am not sure if Shimano's sets provide them, but others do. A browse in an LBS would be helpful.

Honestly, the discussion about stainless steel is irrelevant, but typically BF boffin. Just to add to the discussion, in marine circles, it is considered very bad form to take to stainless steel plate with an angle grinder, which produces surface "rusting" or discoloration. Work hardening by bending also can lead to discoloration.

Prepping a bike for your son?
Take him to the lbs and buy the best quality cables, inners and outers they have. Buy brake blocks. Buy tyres and tubes if they're the slightest bit iffy.
Take all the stuff home and then make HIM fit it all, with you teaching/guiding him. He's going to have to do all of this stuff during his time with the bike so teach him now. Lubricate the cables and if the bike's going to spend any sort of time out in the elements, show him how to add a bit of lube from time to time.

To quote James May (of Top Gear fame) - the best thing my father ever did for me was to make me to fix my own bikes.

Hah! Yeah. I hope by now the OP has just thrown on stainless and called it a day

Yes, had a similar thought... show a man how to fish and all that.