#101
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What would you do?
On Jan 8, 9:09*pm, Ryan Cousineau wrote:
In article , wrote: On Jan 8, 2:23*pm, Carl Sundquist wrote: wrote: On Jan 7, 7:05 pm, " wrote: On Jan 7, 11:48 am, SLAVE of THE STATE wrote: On Jan 6, 11:21 pm, " wrote: On Jan 6, 9:05 pm, wrote: Also, an iceberg might loom up out of nowhere and you could crash and sink. Generally, good steels don't have ductile-to-brittle transition temperatures above 0 C, and often well below. *Common aluminum alloys don't have a DBTT. Some types of stainless steel don't have a DBTT either. *I don't know what type of stainless steel cables are made from. People drive trucks and fly planes in Antarctica. You can't be stupid about that, but it works. *It's not like any cold you can tolerate riding in will cause your bike to snap in half while JRA. My biggest worry about temperature cycles would be their effect on glues. *One of those bonded carbon-aluminum frames might not be the best choice for daily cycles from a 65 deg F house to 20 deg F ride and back. *(Or a 65 deg house to 120 deg heat for that matter.) *On the other hand, I'm sure there are quite a few people who have done this and haven't broken anything yet. Dumbass, I heard tell that the "first" steel hulled ships were prone to sinking cuz the steel cracked in cold waters. I don't know what that means in context, just take it as an anecdote. Dumbass, Yeah, sort of. *This was apparently a problem not understood until Liberty ships sank for unexplained reasons during WWII. *Some mild structural steels have a DBTT above freezing and their strength is significantly weakened. *However, there also were other contributing factors - on the Liberty ships, overloading, fatigue and crack nucleation from stress concentrations (I don't think that was understood until after the postwar failures of the Comet airplane) and cracking along welds. Bicycle frames are made out of stronger steel and while DBTT varies a lot for different steel alloys, I don't think it is plausible that normal winter use will cause frame failures. *Aluminum alloys, as noted, do not have a ductile-brittle transition. There is a persistent legend that the reason the Titanic sank was embrittlement of poor quality steel. *I looked this up before posting. *This does not seem to be the case: the Titanic's hull mostly failed at riveted joints and plates had ductile failures rather than outright snapping. *It was actually made out of *fairly good steel for its day. *Steel embrittlement was an issue, but more important problems were micro crack initiation at the punched rivet holes (later, rules changed to demand drilling instead) and failure of the wrought iron rivets, probably exacerbated by cold. *Also, running full steam into a huge ****ing iceberg. http://en.wikipedia.org/wiki/Liberty...llurgy.nist..g..... . esp. pages 13, 20-25 and Figure 4 This is actually why I made the joke about getting sunk by a looming iceberg while riding. Ben- Hide quoted text - - Show quoted text - the bike was tange cromoly tubes as I recall; it didn't quite fall appart or snap as some people here are trying to conjecture; it just developed a crack near the head tube that I observed while cleaning after a very cold day (-20c); I'm a real neat-freak when it comes to my bikes so if it had occured earlier I would've noticed. But are you saying aluminum is less susceptable to extreme cold ? hmmm, I recall noticing cracks along the weld of my syncros alum. stem also while cleaning during an exterme winter and I also had a large 3in crescent wrench snap on me whole working outdoors in northern alberta in the winter ( I think it was stamped alum). I wouldn't think moderately cold temps would affect the brittleness of metal so severely, but my own experience tells me to be careful when it gets really cold. Raamman, -20c temps was not in the context of the original post or thread. It was training rides with one shoe cover missing. People don't normally do that in -20c temps. You should have clarified that you were referring to temperatures that cold. Regardless, riding in those temperatures is not a guarantee of metal failure. My brother lives in Madison, WI and has ridden his bike to work every day through the past two winters (although it is only a 2 mile distance) with nary a failure of that nature.- Hide quoted text - - Show quoted text - everyone could've clarified or more fully defined all the parameters at the outset - but we tend to speak in terms of generalities and without regard to or awareness of what factors are mitigating importance. it doesn't matter- we don't know what we can learn without asking questions. I realize the 0c is irrelevant to steel - and the car analogy is a very good point to illustrate that; I just worry a bit more riding chinese alum in the boonies during the winter and my wife is hopeless navigating if I need an emergency pick up. I think you worry about the wrong things. -- Ryan Cousineau / "In other newsgroups, they killfile trolls." "In rec.bicycles.racing, we coach them."- Hide quoted text - - Show quoted text - you don't know my wife, sometimes she has trouble finding the door |
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#102
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What would you do?
Paul G. wrote:
As I recall, it was my eyeballs that really suffered on the descent to Aspen. Just keep your eyes closed. |
#103
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What would you do?
Michael Press wrote:
I do _not_. Starbucks. Sausalito. Friday noon. I didn't know you had any purple cycling clothing. |
#105
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What would you do?
Michael Press wrote:
Truckers who work 0 deg F and below must be careful when hammering away at balky hardware. It can break where it will not at higher temperatures. The next time I'm out on a training ride at 0 degrees F I'll have to remember not to "hammer" too hard Bill |
#106
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What would you do?
Carl Sundquist wrote:
I can't help it if people don't read in context. Well, OK. I'll settle for you fixing the bit where people THINK in context, then. |
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