jim beam
12-31-1969, 08:00 PM
* * Chas wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:hNidneOypNDMpQ3bnZ2dnUVZ_iydnZ2d@speakeasy.ne t...
>> * * Chas wrote:
>>> "A Muzi" <am@yellowjersey.org> wrote in message
>>> news:1390c12deh1dg13@corp.supernews.com...
>>>>> <atri.ind@gmail.com> wrote in message
>>>>> news:1183655286.121764.161420@i38g2000prf.googlegr oups.com...
>>>>>> I have a crack in the chain stay of my LeMond Buenos Aires (2004).
>>>>>> This bike has about 8000 miles on it. I have never raced this bike,
>>> or
>>>>>> had a crash.
>>>>>>
>>>>>> The history is that 2 years (and 6K miles) ago, the chain slipped
>>> off,
>>>>>> and got jammed between the frame and the chain ring, and caused a
>>> dent
>>>>>> about 1mm deep vertically on the chain stay (this part of the frame
>>> is
>>>>>> steel). The frame was examined by the LBS at that time, and
> declared
>>>>>> safe to use. Last week, I had a tuneup on the bike, and nothing
>>>>>> further was noticed, but a couple of days ago, I took the bike in
>>>>>> again to have a chain ring replaced due to a slipping chain, and
> they
>>>>>> noticed a 1cm fracture extending from the area of the old dent.
> They
>>>>>> say they noticed nothing last week, and this crack seems to have
>>>>>> become apparent in the last week.
>>>>>>
>>>>>> The LBS sent pictures of the crack to Trek, who said the frame
> needs
>>>>>> to be replaced, but it will not be under warranty since the dent
>>>>>> caused the frame failure.
>>>>>>
>>>>>> Given the two year gap beetween the two events, is this a
> reasonable
>>>>>> conclusion? Is this kind of fracture repairable? At the LBS, they
>>> felt
>>>>>> that the heat from welding could cause a problem since the crack
> was
>>>>>> close to the seat tube (carbon).
>>>>>>
>>>>>> Any suggestions on how either the LBS, or I, could call Trek and
>>>>>> persuade them to cover this under warranty?
>>>> * * Chas wrote:
>>>>> Anecdotal experience: I've been messing around with pro bikes for
> ~35
>>>>> years. I don't ever recall seeing a cracked or broken chain stays on
> a
>>>>> Reynolds 531 frame.
>>>>> I've seen maybe a dozen broken chainstays on Italian built Columbus
>>>>> frames, several in Super Vitus frames made in the 1970s by US
> builders
>>> and
>>>>> a few in frames made from True Temper tubing.
>>>>> I saw several frames with chainstays that broke right at the bottom
>>>>> bracket but I attributed those to overheating during brazing and
> they
>>>>> weren't necessarily pro bikes.
>>>>> The right chainstay was the one that cracked or broke on all of the
>>> other
>>>>> frames. The damage was usually 3" - 6" from the bottom bracket
> shell.
>>> I
>>>>> looked for causes like chain damage but it wasn't apparent on most
> of
>>>>> these bikes and the breaks or cracks usually didn't occur in the
> area
>>> of
>>>>> the chainstay dented for chainring clearance.
>>>>>
>>>>> Yesterday I was talking about this with a local frame builder who's
>>> done a
>>>>> lot of repairs over the years. He said that he saw quite a few
>>> Reynolds
>>>>> 753 frames with cracked or broken chainstays but the only 531 frames
>>> with
>>>>> chainstay problems he'd seen were at the dropouts. The original
>>> Reynolds
>>>>> 753 chainstays were made of very thin wall tubing - .5mm thick.
>>>>> He mentioned that over the years Columbus increased the wall
> thickness
>>> of
>>>>> their chainstays made of SL tubing which started out at .6mm. He
> also
>>> said
>>>>> that he's had to replace chainstays made from Ishiwata and Tange
>>> tubing.
>>>>> During the period that I'm talking about - 1970s to 1990s, most of
> the
>>>>> Columbus, Ishiwata, Tange and True Temper tubing was made of 4130
>>> chrome
>>>>> molybdenum steel. Super Vitus was of a somewhat similar steel.
>>>>> Reynolds 531 was made from a manganese molybdenum steel (manganese -
>>> not
>>>>> to be confused with magnesium). Manganese adds toughness to steel.
> The
>>>>> published strength of Reynolds 531 is usually lower than that of the
>>>>> chrome moly steels. The total amount of alloying elements in these
>>> steels
>>>>> is only around 5% by weight.
>>>>> My guess is that the use of manganese instead of chrome as an
> alloying
>>>>> agent slightly increases the toughness of 531 over 4130. Tougher
> steel
>>> is
>>>>> less prone to cracking.
>>>>> Just an observation and opinion. I own bikes made of Columbus,
>>> Reynolds,
>>>>> Tange and Super Vitus so I have no axe to grind.
>>>> I have replaced cracked 531 stays. My very first frame repair was on
> a
>>>> 1968 Raleigh Pro* with a broken right stay. The high incidence of
>>>> cracked Columbus chainstays in the eighties followed the trend to
>>>> Columbus cast chainstay bridges. Those are small, thick and rigid,
>>>> frequently behind a chain crimp on the outside of the stay, brass
> brazed
>>>> and often hot.
>>>>
>>>> Super Vitus is nearly the same material as 531 and those break too.
>>>>
>>>> There's much more going on besides material and thickness.
> Construction
>>>> details (cast bridges, crimped sections) , sloppy process (high
> brazing
>>>> temperatures, misalignment, poor miters, outright brazing errors),
> rider
>>>> abuse (chain jam dings) all can contribute. I say 'contribute'
> because
>>>> all of those things are known but do not always fail.
>>>>
>>>> I don't conclude that any of the major brands of tube is 'better' or
>>>> 'worse' overall.
>>>>
>>>> * Given the volume of Raleighs, that's not significant. They are no
> more
>>>> prone to cracks than any other brand.
>>>> --
>>>> Andrew Muzi
>>>> www.yellowjersey.org
>>>> Open every day since 1 April, 1971
>>> Like I said, I never saw a cracked or broken 531 chainstay during the
> time
>>> period I listed but I was looking for feedback from others and ideas
> about
>>> the causes of the breaks so far back from the BB and area of chain
> suck.
>>> That's odd about the Raleigh Pro chainstay breaking since they used
> round
>>> chainstays without dimples. Those tubes were that same as Reynolds
> round
>>> track fork "blades". The same tubes were also flattened into an oval
> shape
>>> regular fork blades.The early Pros were made with fairly heavy gage
>>> Reynolds 531 pipe.
>> "pipe" means it's seamed, "tube" is seamless. there's never been any
>> 531 pipe to my knowledge.
>
> Where the f$%% are you coming from?
>
> The term "pipe" has nothing to do with the manufacturing processes used in
> the production tubular metal products. You've stepped over your 1st year
> engineeering student level of knowledge and experience!
>
> Pipe can be cast, seam welded and/or DOM (drawn over mandrel) - the
> generic term "pipe" refers to a hollow cylindrical metal product with a
> certain minimum unspecified wall thickness.
>
> There are several different methods for producing pipe and tubing using
> the seamed and welded process:
>
> 1. Roll forming - folding a sheet of metal into a tubular shape and
> welding the joint via induction welding, submerged arc welding or other
> joining methods. This leaves a non-homogeneous area at the joint and a
> ridge at the weld site inside the tube/pipe. Roll formed DOM tubing is
> supposed to have a uniform metallurgical structure at the joint but True
> Temper tubing made using this process contradicts this claim.
>
> Peugeot used forks made of sheet metal rolled and brazed into shape on
> their U-08, PR-10 and other models during the US Bike Boom in the 1970s.
> These forks where not really made of tubing. When bent, these forks would
> split at the seam.
>
> The other day someone showed me a down tube cut from an older Pogliaghi
> frame that had a perfect seamed weld down the middle of the ID of the
> tube. The frame was supposed to be made of Reynolds or Columbus tubing.
> Durifort, Vitus 172 and some True temper bicycle tubing used this welded
> seam process.
>
> Here's some sites showing the manufacturing processes for seamed tubing.
>
> http://www.unicorn-automation.co.uk/article3.htm
>
> http://www.markintubing.com/manufacturing.html
>
> Clicking on "Slitting" and "Tube Mills" brings up Quicktime presentations
> on the subject.
>
> 2. Rolling a sheet of metal into a tubular shape with multiple overlaps
> around a mandrel - the heat and pressure used in the process "welds" the
> layers into a somewhat homogeneous state. This is frequently refereed to
> as "seamless" tubing.
>
> DOM or Drawn Over Mandrel produces the best quality pipe and tubing. DOM
> tubing and pipe can be made from solid homogenous slugs, seam welded or
> lapped material.
>
> A slug of metal is pierced or drilled in the center so that a mandrel can
> be inserted. The OD and ID size is mechanically established by rolling,
> drawing or extruding the metal slug with the mandrel inside.
>
> Here's a site that shows the DOM process.
>
> http://www.steeluniversity.org/content/html/eng/default.asp?catid=199&pageid=2081272066
>
> Reynolds used their 531 steel for many different applications - 531 stands
> for the ratio of alloys in the steel - don't ask, it doesn't make since to
> me. It's been around since before WWI. It was developed for use in WWI
> aircraft frames for more strength and fatigue resistance over standard
> carbon steels.
>
> At the time the Brits had dificulty getting chrome at an economical price
> but had ample access to supplies of manganese so they developed a steel
> alloy using this element. The percentage of alloys in 531 and 4130 (chrome
> moly steel) is only around 5% by weight.
>
> Chas.
>
>
let me attempt to help your edumacation. i happen to have had the
privilege of working in a tube factory. this included both "tube" and
"pipe". tube, of whatever material, was seamless cylinder drawn from
pierced slugs of solid metal. that is a long and expensive process, but
yields the best mechanical properties. pipe otoh is simply flat sheet
rolled and seam welded. it's way cheaper, but carried performance
penalties.
now, /you/ can call this stuff whatever you like - presumably you're a
plumber and aren't too worried about physical performance - but if
you're an engineer with design criteria can can only be fulfilled by
tube, you're not going to use pipe. and if you are price engineering,
you're going to use pipe, not tube.
have a nice day.
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:hNidneOypNDMpQ3bnZ2dnUVZ_iydnZ2d@speakeasy.ne t...
>> * * Chas wrote:
>>> "A Muzi" <am@yellowjersey.org> wrote in message
>>> news:1390c12deh1dg13@corp.supernews.com...
>>>>> <atri.ind@gmail.com> wrote in message
>>>>> news:1183655286.121764.161420@i38g2000prf.googlegr oups.com...
>>>>>> I have a crack in the chain stay of my LeMond Buenos Aires (2004).
>>>>>> This bike has about 8000 miles on it. I have never raced this bike,
>>> or
>>>>>> had a crash.
>>>>>>
>>>>>> The history is that 2 years (and 6K miles) ago, the chain slipped
>>> off,
>>>>>> and got jammed between the frame and the chain ring, and caused a
>>> dent
>>>>>> about 1mm deep vertically on the chain stay (this part of the frame
>>> is
>>>>>> steel). The frame was examined by the LBS at that time, and
> declared
>>>>>> safe to use. Last week, I had a tuneup on the bike, and nothing
>>>>>> further was noticed, but a couple of days ago, I took the bike in
>>>>>> again to have a chain ring replaced due to a slipping chain, and
> they
>>>>>> noticed a 1cm fracture extending from the area of the old dent.
> They
>>>>>> say they noticed nothing last week, and this crack seems to have
>>>>>> become apparent in the last week.
>>>>>>
>>>>>> The LBS sent pictures of the crack to Trek, who said the frame
> needs
>>>>>> to be replaced, but it will not be under warranty since the dent
>>>>>> caused the frame failure.
>>>>>>
>>>>>> Given the two year gap beetween the two events, is this a
> reasonable
>>>>>> conclusion? Is this kind of fracture repairable? At the LBS, they
>>> felt
>>>>>> that the heat from welding could cause a problem since the crack
> was
>>>>>> close to the seat tube (carbon).
>>>>>>
>>>>>> Any suggestions on how either the LBS, or I, could call Trek and
>>>>>> persuade them to cover this under warranty?
>>>> * * Chas wrote:
>>>>> Anecdotal experience: I've been messing around with pro bikes for
> ~35
>>>>> years. I don't ever recall seeing a cracked or broken chain stays on
> a
>>>>> Reynolds 531 frame.
>>>>> I've seen maybe a dozen broken chainstays on Italian built Columbus
>>>>> frames, several in Super Vitus frames made in the 1970s by US
> builders
>>> and
>>>>> a few in frames made from True Temper tubing.
>>>>> I saw several frames with chainstays that broke right at the bottom
>>>>> bracket but I attributed those to overheating during brazing and
> they
>>>>> weren't necessarily pro bikes.
>>>>> The right chainstay was the one that cracked or broke on all of the
>>> other
>>>>> frames. The damage was usually 3" - 6" from the bottom bracket
> shell.
>>> I
>>>>> looked for causes like chain damage but it wasn't apparent on most
> of
>>>>> these bikes and the breaks or cracks usually didn't occur in the
> area
>>> of
>>>>> the chainstay dented for chainring clearance.
>>>>>
>>>>> Yesterday I was talking about this with a local frame builder who's
>>> done a
>>>>> lot of repairs over the years. He said that he saw quite a few
>>> Reynolds
>>>>> 753 frames with cracked or broken chainstays but the only 531 frames
>>> with
>>>>> chainstay problems he'd seen were at the dropouts. The original
>>> Reynolds
>>>>> 753 chainstays were made of very thin wall tubing - .5mm thick.
>>>>> He mentioned that over the years Columbus increased the wall
> thickness
>>> of
>>>>> their chainstays made of SL tubing which started out at .6mm. He
> also
>>> said
>>>>> that he's had to replace chainstays made from Ishiwata and Tange
>>> tubing.
>>>>> During the period that I'm talking about - 1970s to 1990s, most of
> the
>>>>> Columbus, Ishiwata, Tange and True Temper tubing was made of 4130
>>> chrome
>>>>> molybdenum steel. Super Vitus was of a somewhat similar steel.
>>>>> Reynolds 531 was made from a manganese molybdenum steel (manganese -
>>> not
>>>>> to be confused with magnesium). Manganese adds toughness to steel.
> The
>>>>> published strength of Reynolds 531 is usually lower than that of the
>>>>> chrome moly steels. The total amount of alloying elements in these
>>> steels
>>>>> is only around 5% by weight.
>>>>> My guess is that the use of manganese instead of chrome as an
> alloying
>>>>> agent slightly increases the toughness of 531 over 4130. Tougher
> steel
>>> is
>>>>> less prone to cracking.
>>>>> Just an observation and opinion. I own bikes made of Columbus,
>>> Reynolds,
>>>>> Tange and Super Vitus so I have no axe to grind.
>>>> I have replaced cracked 531 stays. My very first frame repair was on
> a
>>>> 1968 Raleigh Pro* with a broken right stay. The high incidence of
>>>> cracked Columbus chainstays in the eighties followed the trend to
>>>> Columbus cast chainstay bridges. Those are small, thick and rigid,
>>>> frequently behind a chain crimp on the outside of the stay, brass
> brazed
>>>> and often hot.
>>>>
>>>> Super Vitus is nearly the same material as 531 and those break too.
>>>>
>>>> There's much more going on besides material and thickness.
> Construction
>>>> details (cast bridges, crimped sections) , sloppy process (high
> brazing
>>>> temperatures, misalignment, poor miters, outright brazing errors),
> rider
>>>> abuse (chain jam dings) all can contribute. I say 'contribute'
> because
>>>> all of those things are known but do not always fail.
>>>>
>>>> I don't conclude that any of the major brands of tube is 'better' or
>>>> 'worse' overall.
>>>>
>>>> * Given the volume of Raleighs, that's not significant. They are no
> more
>>>> prone to cracks than any other brand.
>>>> --
>>>> Andrew Muzi
>>>> www.yellowjersey.org
>>>> Open every day since 1 April, 1971
>>> Like I said, I never saw a cracked or broken 531 chainstay during the
> time
>>> period I listed but I was looking for feedback from others and ideas
> about
>>> the causes of the breaks so far back from the BB and area of chain
> suck.
>>> That's odd about the Raleigh Pro chainstay breaking since they used
> round
>>> chainstays without dimples. Those tubes were that same as Reynolds
> round
>>> track fork "blades". The same tubes were also flattened into an oval
> shape
>>> regular fork blades.The early Pros were made with fairly heavy gage
>>> Reynolds 531 pipe.
>> "pipe" means it's seamed, "tube" is seamless. there's never been any
>> 531 pipe to my knowledge.
>
> Where the f$%% are you coming from?
>
> The term "pipe" has nothing to do with the manufacturing processes used in
> the production tubular metal products. You've stepped over your 1st year
> engineeering student level of knowledge and experience!
>
> Pipe can be cast, seam welded and/or DOM (drawn over mandrel) - the
> generic term "pipe" refers to a hollow cylindrical metal product with a
> certain minimum unspecified wall thickness.
>
> There are several different methods for producing pipe and tubing using
> the seamed and welded process:
>
> 1. Roll forming - folding a sheet of metal into a tubular shape and
> welding the joint via induction welding, submerged arc welding or other
> joining methods. This leaves a non-homogeneous area at the joint and a
> ridge at the weld site inside the tube/pipe. Roll formed DOM tubing is
> supposed to have a uniform metallurgical structure at the joint but True
> Temper tubing made using this process contradicts this claim.
>
> Peugeot used forks made of sheet metal rolled and brazed into shape on
> their U-08, PR-10 and other models during the US Bike Boom in the 1970s.
> These forks where not really made of tubing. When bent, these forks would
> split at the seam.
>
> The other day someone showed me a down tube cut from an older Pogliaghi
> frame that had a perfect seamed weld down the middle of the ID of the
> tube. The frame was supposed to be made of Reynolds or Columbus tubing.
> Durifort, Vitus 172 and some True temper bicycle tubing used this welded
> seam process.
>
> Here's some sites showing the manufacturing processes for seamed tubing.
>
> http://www.unicorn-automation.co.uk/article3.htm
>
> http://www.markintubing.com/manufacturing.html
>
> Clicking on "Slitting" and "Tube Mills" brings up Quicktime presentations
> on the subject.
>
> 2. Rolling a sheet of metal into a tubular shape with multiple overlaps
> around a mandrel - the heat and pressure used in the process "welds" the
> layers into a somewhat homogeneous state. This is frequently refereed to
> as "seamless" tubing.
>
> DOM or Drawn Over Mandrel produces the best quality pipe and tubing. DOM
> tubing and pipe can be made from solid homogenous slugs, seam welded or
> lapped material.
>
> A slug of metal is pierced or drilled in the center so that a mandrel can
> be inserted. The OD and ID size is mechanically established by rolling,
> drawing or extruding the metal slug with the mandrel inside.
>
> Here's a site that shows the DOM process.
>
> http://www.steeluniversity.org/content/html/eng/default.asp?catid=199&pageid=2081272066
>
> Reynolds used their 531 steel for many different applications - 531 stands
> for the ratio of alloys in the steel - don't ask, it doesn't make since to
> me. It's been around since before WWI. It was developed for use in WWI
> aircraft frames for more strength and fatigue resistance over standard
> carbon steels.
>
> At the time the Brits had dificulty getting chrome at an economical price
> but had ample access to supplies of manganese so they developed a steel
> alloy using this element. The percentage of alloys in 531 and 4130 (chrome
> moly steel) is only around 5% by weight.
>
> Chas.
>
>
let me attempt to help your edumacation. i happen to have had the
privilege of working in a tube factory. this included both "tube" and
"pipe". tube, of whatever material, was seamless cylinder drawn from
pierced slugs of solid metal. that is a long and expensive process, but
yields the best mechanical properties. pipe otoh is simply flat sheet
rolled and seam welded. it's way cheaper, but carried performance
penalties.
now, /you/ can call this stuff whatever you like - presumably you're a
plumber and aren't too worried about physical performance - but if
you're an engineer with design criteria can can only be fulfilled by
tube, you're not going to use pipe. and if you are price engineering,
you're going to use pipe, not tube.
have a nice day.