Wednesday, July 26, 2017

Authentic Austenitic

Meet the Warakin. It is austenitic stainless steel.
My RidingGravel.com gig has afforded me the opportunity to try something out I've never tried before. After having been on so many different bikes in my lifetime, and especially in the last 15 years, that's saying something.

The thing in question is the frame material this bicycle from Otso Cycles is made from. It is a frame made from stainless steel. The bike is called the Warakin. The steel it is made from is not only stainless, but it is a certain kind of stainless.

I remember seeing the press release for this model from Otso Cycles and seeing an image of the frame tubing sticker. It had "Austenitic Stainless Steel" printed on that sticker. I laughed. I thought someone got "Authentic" spelled wrong. Well, the joke ended up being on me. You see, there are actually three kinds of stainless steel, and Austenitic Stainless Steel is one of them. (Click and learn, my friends. Click and learn) I had no idea before I saw this sticker that there were three major groups of stainless alloys. The internet sometimes really is the "information super-highway" and not always the "Info-tainment Super-Highway". Who knew?

Well, now I know! Anyway, stainless steel frames were ballyhooed a few years back and were said to be the "next big deal" in bicycle frames. Stainless (I checked and it seems that the big promoter in this was a maker of martensitic stainless steel), was supposedly lighter than Titanium and stronger than typical steels used in bicycle tubing. But then I never heard a lot about stainless frames until Salsa Cycles made their Vaya Travel. I thought that frame was rad, but I never did end up getting one.

So, anyway, all that to say that this bike is one of the rare ones out there made from stainless and as far as I know, the only "austenitic" stainless steel one. At least, the only one advertised as such.

Ya learn something new everyday........if you have an open mind!

13 comments:

phillip Cowan said...

At the risk of sounding like Nicky Know It All I have say the word is "austenitic". It's not really such a big deal. Your kitchen sink is probably made from 304L which is austenitic. None of 300 series stainless steels are heat treatable to any degree. Their chief virtues seem to be corrosion resistance and they TIG weld really nice. Compared to a good carbon tool steel from Reynolds or Columbus stainless is a little soft and a little dead. I once built a custom stem out of 316L. It came out okay but it's heavier than one made from real bike tubing. Maybe Otso is going to tell us this is some new wonder alloy with different properties and that I should shut the hell up so I will stand by and wait to be schooled.


Guitar Ted said...

@phillip Cowan- My brief research came up with some things I didn't know about stainless steel, which, as you say, "is no big deal" because we deal with it everyday. However; I wasn't aware that there were different types, and within those there can be variances to degrees which I also wasn't aware of.

Otso doesn't have a lot of info as to the "why" of stainless steel in there design. I have asked them to explain further but I have not heard back from them yet.

I did find out that austenitic stainless gains strength from cold working and drawing of the material through dies. It also is the best at corrosion resistance of all the stainless steels and is not magnetic. This would seem to give the material some qualities of titanium.

I don't know about a "dead" feeling ride quality for other stainless steel frames, but I can say this one is definitely not "dead" feeling.

phillip Cowan said...

Yeah, the stuff work hardens easily which is what makes it somewhat bothersome to machine. You have to keep the tool moving and not let it dwell. Work hardening will strengthen it somewhat but will probably make it more likely to fatigue crack in a thin section like a frame tube. Better I think to stick with the 400 series(martensitic) tubing like Reynolds 953 or Columbus XCr. Since I'm a poor working schmuck this is all academic to me. I can't afford any of these frames. But if I suddenly hit the Lotto I would Check with Scott Quiring in Michigan. He seems to be the guru on these things and I believe he uses the Columbus tubing.

youcancallmeAl said...

There are at least FIVE types of stainless steel.

youcancallmeAl said...

301L austenitic stainless is not heat treatable but it can be cold worked to a fair degree of strength. But I can't see the advantages over Martensitic or precipitation hardening grades other than increased corrosion resistance and who is riding in such corrosive places?

Rainier Wolfcastle said...

953 might be better, but this is a lot cheaper (frameset is like 1800). If it's the most corrosion resistant of the SSs, good, because I ride year round in Minneapolis.

I upgraded my Vaya to this. The frame weights are about the same but the Warakin seems more alive.

Guitar Ted said...

@youcancallmeAl- See Rainier Wolfcastle's comment and I would second that notion. I have had bad corrosive problems with whatever the heck they spray on the streets mixed with whatever the heck precipitates are falling off cars these days on my commutes. Stainless steel disc brake rotors are even no match.

I'm not sure austenitic stainless would hold up, because I don't know what they use for rotors, but if it is the best, short of titanium, I could see this as being an all-weather option here in the Snow Belt.

phillip Cowan said...

Austenitic stainless is not as impervious as you might think. It's prone to inter-granular corrosion whereby chlorine (from road salt, seawater etc.)eats away the the grain boundaries of the metal resulting in sudden catastrophic failure. If it didn't have this problem the Navy would probably build ships out of it. A few years back the Spanish Americas Cup team lost their bolt on keel out in the open ocean. It just fell off. I believe it was traced back to stainless bolts. Knowing this I would be very hesitant to ride such a frame in salty winter slush. I'm not sure if the Martensitic steels suffer from this problem.

Guitar Ted said...

@phillip Cowan: Good point, but they quit using salt here years ago. It's MagChloride, or some chemical nonsense. It's sprayed on before it even snows here. Not sure exactly what it is they use. I suppose it is as bad as salt, but I don't know. They used to use straight salt here years ago, but I haven't seen it used in a long time.

phillip Cowan said...

Yeah, it's chlorine component that does it, whether sodium chloride or magnesium chloride.

youcancallmeAl said...

The keel bolt failure would probably be due to stress corrosion cracking and would be transgranular rather than grain boundary corrosion. The bolts would have a preload tensile stress due to tensioning plus a variable stress due to varying side loads on the keel. Austenitic steels are very susceptible to chloride induced SCC.

youcancallmeAl said...

Martensitic steels are MORE susceptible to pitting corrosion in a chloride environment than are austenitic steels.

phillip Cowan said...

Probably still outlast the average polyester bike. Save the polyester for your powder blue leisure suit. LOL.