Why a Stainless Frame?
 

Just curios what the commotion is about SS Frame sets, the excitement over the Schwinn announcement has got me thinking. I've been riding long enough to remember: Cro-Mo, then Alum, then back to Cro-Mo, Carborn Fiber, back to Cro-Mo again, Ti and now SS. I'm ignoring wood, plastic, bamboo and yes even wire frames as the fads and experiments they where/are.

So why SS.....is it a fad or what?

Stainless Steel - in Reynolds 953 or 921 - its main advantage is that it will NEVER rust! No coat of paint is needed and the beautiful naked steel is half the pleasure of owning the bike. Plus, the lighter weight is also worth the price.

See the Waterford thread on C&V for a more through discussion.

A stainless steel frame will never fade.

ask scooper

Isn't SS made via some sort of electro chemical reaction?

Because it looks nice? I like it when things look nice.

I have to admit that I don't know the composition of Reynolds tubing but in general, SS tubes are resistant to rust but aren't rust free. If you live where sweat will drip onto the tubes and you don't clean it off, even stainless will rust. Different tubes, depending on composition will be more or less resistant.
KVA is another player in the stainless market. Their tubes definitely come in at a lighter weight than standard chromoly and are nicely finished.

I like nice, paint is nice, my SS kitchen is nice.... in a sterile, industrial kinda way.

Stainless is harder than regular steel, including 531 so you can make the walls thinner and therefore lighter. This comes at a price- IME stainless is often more brittle. It is certainly harder to work as anyone who has tried to drill it knows.

A frame made with stainless weighs about the same as TI, but should be less whippy. I hear stainless rides just like good 531 steel, but simply weighs less. I should know soon- just got a stainless frame. Its really pretty... but I'm still building it up.

Old news:
Crescent rostfria

No, stainless steels are created from a variety of different alloying elements, so they are different at the metallurgical level from conventional steels. And different varieties of SS have different resistance to corrosion, some are partially magnetic and some essential non-magnetic, some are heat-treatable, and some aren't, and so on.

Regardless of the chemical composition, polished SS looks great. Chromoly that's treated with Framesaver or a similar product on the inside and a good paintjob on the outside will last as long as a stainless bike but if you like bling, there's only one choice.

Against my better judgment, I'm going to venture down the rabbit hole. I'm not a pitch man for stainless, but I am an unabashed fan. Are stainless frames a fad? Perhaps, but the fact that in seven years five different stainless tubesets have been developed and are in production by three separate tubing manufacturers, and after a somewhat tepid start in 2005-2007 with a few adventurous framebuilders experiencing great success building stainless steel frames many more have hopped on the bandwagon suggest it isn’t a fad.

Why stainless frame?

1) It's steel, and there are lots of cyclists who still prefer the resilient ride and “bend, not break” failure mode of a steel frame.

2) Reynolds 953, one of the stainless tubesets, has the highest ultimate tensile strength (1750 - 2050 MPa) and yield strength (1500 - 1900 MPa) of any steel alloy commonly used for bicycle frames. 1500 MPa yield strength is approximately twice the yield strength of cold-worked, stress-relieved 3-2.5 titanium. This high strength means that the tubes can be drawn with thinner walls than tubes with lower UTS and YS, making the frames lighter. As with non-stainless steels, flexy frames resulting from the thin walled tubing can be made stiffer by increasing the tube diameter using OS or double OS tubing. With a hardness of 44 HRc, in spite of wall thickness as thin as 0.3mm, the tubes are very impact resistant yet with an elongation of 14% has similar ductility to other steel alloys that are substantially softer. The assertion that harder means brittle isn’t true. Elongation is the property used to describe a material's range from brittle on one end of the scale (low elongation) to ductile on the other end (high elongation). For example, carbon fiber reinforced polymer has elongation of around 1% to 3% and is brittle. Plain carbon steels, chromoly steels, and the stainless steels all in the condition ready to be used in bicycle frames have elongation in the 10% to 15% range, which is pretty ductile.

For anyone who missed it, here are the properties of the five currently available stainless tubesets. It is worth noting that, in spite of the 44 HRc hardness of 953, Reynolds ovalized 953 round tubes to 70% of its original diameter without any sign of microscopic cracking as a test of ductility.

http://i32.photobucket.com/albums/d7...ps40261e32.jpg

3) All of these stainless alloys with high chromium content are corrosion resistant. As Reynolds puts it with typical British understatement, "Under some conditions, e.g. sulfuric acid or prolonged submersion in sea water, 953 will show signs of pitting and corrosion. We assume these are not normal conditions for a bike frame." Even in a humid salt air environment and riding frequently in rainy weather, it's unlikely you'll ever see rust. A polished, unpainted surface has the appearance of having been chrome plated; you never have to worry about paint getting scratched and having an exposed steel surface rusting.

4) Like many non-stainless air-hardening steels, the stainless tubesets are suitable for brazed lugged, fillet brazed, and TIG welded construction.

All five of the currently available stainless tubesets can make light, stiff, corrosion resistant frames.

In summary, a stainless frame provides all the qualities of steel plus the lower maintenance and some would say attractiveness of a bare polished finish. Is it worth the premium over a high-end non-stainless painted steel frame? After seven years riding my Waterford it is to me, but to lots of folks probably not.

EDIT - Is stainless harder to work with and harder on machining tools? 953 certainly is, but a number of builders who have worked with both 953 and KVA MS2 and MS3 say the KVA tubes are much easier to work with.

Columbus foco (and now Life tubeset?) is pretty close to stainless, and having ridden road and MTB foco bikes, it makes a for great ride.

I worked in industry as an industrial mechanic and had many many opportunities to work with steel, aluminum, stainless steel and even titanium. What I learned there and doing that for close to forty years is that stainless steel is not harder than regular steel, it is considerably softer. In fact this problem is so great that we had to use a special lubricant on threads to prevent them from "picking-up and seizing together.

As for strength, not sure if it is stronger or weaker than regular or chrome moly steel. It does fade (oxidize) with time just like everything else. And, keep in mind that there are different grades of stainless steel.

But it is pretty and, as others have mentioned, probably not as good as chrome moly or something similar. Just my opinion on that last comment.

[MENTION=38510]Scooper[/MENTION], thanks as always for your valuable and informed input, along with the technical details to back it up.

I don't have anything to add, except that I saw a few really attractive SS frames at the NAHBS in Sacramento a couple years ago. Steve Rex had a beautiful example with polished lugs that resembled chrome (without the drawbacks of chrome--environmental impact, potential for corrosion, etc.).

http://i850.photobucket.com/albums/a...o/IMG_4254.jpg

http://i850.photobucket.com/albums/a...o/IMG_4032.jpg

It has most of the advantages of ti and you can use lugs.

"Stainless" steel is a category, not a specification. So you can't generalize about the properties of "Stainless" steel. You need to pick an exact specification and, if necessary, heat treatment, cold working etc.
Then the properties can be nailed down.

Put me in the fan section...

Stainless will rust, eventually, very lightly on the surface. I've had it occur on non-bicycle items, and just barely noticably on the bike below. Something as simple as auto wax can protect it for a very long time though. These lines of stainless are harder than the stuff kitchen utensils are made of, the specs prove it as so. Scooper summed up the properties very well, but for me these were the selling points:

• It is very hard and can be drawn into thin tubes without great fear of denting
• It need not be painted, though it certainly can be
• A brushed finish can be refreshed, by me, at anytime with results much better than my paint touch up jobs
• Ride it hard, put it away wet, no problem
• Grey matches my hair

The rest of the benefits are true of any fine custom:

• The ride is sublime, tailored by the builder to your needs, not an off the rack carbon type of thing
• Dream it, they will build it
• If it is your dream bike, why not get it made of a material that has arguable benefits and a certain rarity

http://www.bikeforums.net/attachment...4&d=1409959853
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Bingo!

Dave Anderson was one of the pioneers, and his experience and attention to detail really show in the end result. Besides that, he's a helluva nice guy.

OH that's right, Rigi made a Stainless model in '80

http://www.bikeforums.net/attachment...9&d=1290573381

Right; that's why I included the standards for each tubeset in the table and the ranges of property values. The value of a given sample is dependent on condition.

Anybody can look up the UNS, DIN, AISI, etc., standards online.

I've had Revere Ware pans for 30+ years.
The Soma Stanyan has beautiful stainless lugs.
The DeLorean had stainless steel body panels.
I'd not hesitate to steal Chrome Molly's stainless.
They make good spokes, and excellent cheese vats.
Lighter and stronger than other kitchen sinks.

Crescent of Sweden made the Mark XX stainless frame in the early seventies.

http://i32.photobucket.com/albums/d7...ps891ca75b.jpg

http://i32.photobucket.com/albums/d7...ps3a95688f.jpg