Advertise on Bikeforums.net



User Tag List

Page 2 of 5 FirstFirst 1234 ... LastLast
Results 26 to 50 of 102
  1. #26
    Senior Member no motor?'s Avatar
    Join Date
    Dec 2005
    Location
    Chicagoland
    My Bikes
    Specialized Hardrock
    Posts
    3,927
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by JamesRL View Post
    Lots of cheap steel bikes available used, some from reputable bike shops that will have them tuned and ready to go. I prefer the feel.
    Indeed. A lot of us are happily riding steel framed mountain bikes from the last century.

  2. #27
    Banned.
    Join Date
    Sep 2013
    Posts
    1,558
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DiabloScott View Post
    Not sure why this is important since the cause here is certainly not fatigue.

    But ALL fatigue starts with a crack. Steel frames with cracks will absolutely fatigue. Aluminum's lack of a fatigue limit means that the cracks can appear without previously being damaged - it doesn't mean it'll be a certain failure at an unsuspecting time.

    In regards to this particular bicycle, there's no possible way for us to determine the direct cause of the OP's frame failure. All we can do at this point is speculate and discuss possibilities. The scientific data suggests that his frame failure was most likely, due to fatigue. How you can state unequivocally for certain, that it was not, is beyond my comprehension. Speculation always favors science, not anecdotal testimony.

  3. #28
    It's MY mountain DiabloScott's Avatar
    Join Date
    Sep 2006
    Location
    Mt.Diablo
    Posts
    5,474
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WestPablo View Post
    In regards to this particular bicycle, there's no possible way for us to determine the direct cause of the OP's frame failure. All we can do at this point is speculate and discuss possibilities. The scientific data suggests that his frame failure was most likely, due to fatigue. How you can state unequivocally for certain, that it was not, is beyond my comprehension. Speculation always favors science, not anecdotal testimony.

    We don't have any scientific data in this case; we have one anecdotal story.

    We have one description of one guy's seat tube that broke in an area that doesn't see the typical kind of cyclical stresses required for fatigue failure, and in an area where the rare failure is almost always due to damage. We also have the description of a "clean break", which is also not a characteristic of fatigue.

    Now if the OP is somehow especially hard on seat tubes, then steel would probably be a better choice for him anyway, but that's because it can handle more damage before it weakens.
    http://diabloscott.blogspot.com/

  4. #29
    Senior Member
    Join Date
    May 2014
    Posts
    144
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    You can try Public and I believe Linus as well.

  5. #30
    Senior Member tjspiel's Avatar
    Join Date
    Jun 2007
    Location
    Minneapolis
    Posts
    6,822
    Mentioned
    9 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WestPablo View Post
    In regards to this particular bicycle, there's no possible way for us to determine the direct cause of the OP's frame failure. All we can do at this point is speculate and discuss possibilities. The scientific data suggests that his frame failure was most likely, due to fatigue. How you can state unequivocally for certain, that it was not, is beyond my comprehension. Speculation always favors science, not anecdotal testimony.
    Actually it sounds like he was unintentionally using his seat post as a big lever and broke the top of his seat tube off.
    If you're not riding with a psychedelic gecko on your shirt, you ARE having a substandard experience.

  6. #31
    Banned.
    Join Date
    Sep 2013
    Posts
    1,558
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DiabloScott View Post
    We don't have any scientific data in this case; we have one anecdotal story.

    We have one description of one guy's seat tube that broke in an area that doesn't see the typical kind of cyclical stresses required for fatigue failure, and in an area where the rare failure is almost always due to damage. We also have the description of a "clean break", which is also not a characteristic of fatigue.

    Now if the OP is somehow especially hard on seat tubes, then steel would probably be a better choice for him anyway, but that's because it can handle more damage before it weakens.
    Scientific data abounds concerning most metals, especially the kind found in the bicycle industry. We know more about steel, because we've been using it to make bicycles for over a century. We also know enough about aluminum to postulate failure probabilities, when compared to that of chromoly steel. Therefore, since we're just speculating anyway, I say, aluminum fatigue is the most likely suspect here, in the absence of any formidable conclusive evidence. It's just a better guess. That's all!

    PS.

    Cyclical stress comes in the form of vibrations. The entire bicycle frame vibrates.
    Last edited by WestPablo; 05-22-14 at 02:31 PM.

  7. #32
    Banned.
    Join Date
    Sep 2013
    Posts
    1,558
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by tjspiel View Post
    Actually it sounds like he was unintentionally using his seat post as a big lever and broke the top of his seat tube off.
    In the world of speculation, all bids are accepted!

  8. #33
    It's MY mountain DiabloScott's Avatar
    Join Date
    Sep 2006
    Location
    Mt.Diablo
    Posts
    5,474
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WestPablo View Post
    Scientific data abounds concerning most metals, .
    We don't have any scientific data on THIS PARTICULAR FAILURE. We don't even have a good description of it.

    Google up photos of broken seat tubes -

    Here's the first one that came up for me - this is fatigue, down at the bottom tube where stresses are concentrated and cyclical, and pre-existing damage from welding can be present.

    Titanium


    Another:



    They're almost ALL at the welds (or lugs) - either BB or top tube joint. Hardly any aluminum ones in my results.

    Or else they're the result of obvious damage or misuse (seat post insertion length issue).

    Undamaged seat tubes simply do not fail in mid span from fatigue... aluminum or otherwise.
    Last edited by DiabloScott; 05-22-14 at 04:03 PM.
    http://diabloscott.blogspot.com/

  9. #34
    Banned.
    Join Date
    Mar 2010
    Posts
    523
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    1. which bike is it?

    2. how much do you weigh?

    3. did you overtighten the seatpost clamp or QR lever?

    4. do you realize any material can fail?

    Quote Originally Posted by Sullalto View Post
    So, like the subject says: what are some cheap($400-1000) steel framed bike?

    Would prefer a complete bike, but a build isn't totally out of the question.

    I only have one bike, a comfort bike that I bought for myself last Christmas. And the seat tube just broke cleanly, right above where the seat stays meet it.

    It's an alarming experience, I don't recommend it.

    So if decided: no more aluminum bikes. I want the more forgiving failure quality of steel.

    I'm only aware of Jamis' steel bikes-they have a steel hybrid, and a steel road bike line. What other manufacturers make steel bikes these days?

    I know to look at touring bikes, but I'm wondering if anything else is out there.

    Thanks!

  10. #35
    Banned.
    Join Date
    Sep 2013
    Posts
    1,558
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DiabloScott View Post
    We don't have any scientific data on THIS PARTICULAR FAILURE. We don't even have a good description of it.

    Google up photos of broken seat tubes -

    Here's the first one that came up for me - this is fatigue, down at the bottom tube where stresses are concentrated and cyclical, and pre-existing damage from welding can be present.


    Another:



    They're almost ALL at the welds (or lugs) - either BB or top tube joint. Hardly any aluminum ones in my results.

    Or else they're the result of obvious damage or misuse (seat post insertion length issue).

    Undamaged seat tubes simply do not fail in mid span from fatigue... aluminum or otherwise.
    Enjoyed your two photos...

    Thank you!

  11. #36
    Senior Member Papa Tom's Avatar
    Join Date
    Aug 2008
    Location
    Long Island, New York
    My Bikes
    The same GT Outpost Mountain bike I've been riding since 1996. I also have a collection of cruisers, folders, and some antiques.
    Posts
    1,967
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    I had no idea they weren't making steel bikes anymore! My trusty 1996 GT Outpost, with a zillion miles on it, is going to fail me SOME day. Does this mean my next bike is going to have to be aluminum?
    Papa Tom

    "I just need a rest...and by 'rest' I mean a really long bicycle ride."

  12. #37
    Banned.
    Join Date
    Mar 2010
    Posts
    523
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Papa Tom View Post
    I had no idea they weren't making steel bikes anymore! My trusty 1996 GT Outpost, with a zillion miles on it, is going to fail me SOME day. Does this mean my next bike is going to have to be aluminum?
    We'll all just have to ride bikes in our imagination in the future. Limitless possibilities!

  13. #38
    Prefers Cicero cooker's Avatar
    Join Date
    Jul 2005
    Location
    Toronto
    My Bikes
    1984 Trek 520; 1990s Peugeot (Canadian-made) rigid mountain bike; 2007 Bike Friday NWT; misc others
    Posts
    8,449
    Mentioned
    23 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fietsbob View Post
    You may now be educated , The seat post was not long enough , for the height you pulled it up to ..

    Not the bike companies failing , but the User.
    Are you saying he bought the seat post?

  14. #39
    PatronSaintOfDiscBrakes dynaryder's Avatar
    Join Date
    Apr 2005
    Location
    dropped and lost in Washington DC
    Posts
    5,899
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by WestPablo View Post
    "Titanium is not as strong as steel and it is not as light as aluminum. The result is a frame that has a better ride than aluminum, but weighs more. It doesn't ride as well as steel, but it is lighter."

    That's all BS. Ti is stronger than steel,rides just as well,and can be about as light as alum.

    "I still hold that a modern steel bike built with hand-made cross-three wheels and good tires inflated to a maximum of 110 psi remains the gold standard. No other bike will ride as well."


    C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport/Qualifier,Brompton S6L,Dahon Speed Pro TT

  15. #40
    Banned.
    Join Date
    Sep 2013
    Posts
    1,558
    Mentioned
    15 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dynaryder View Post
    "Titanium is not as strong as steel and it is not as light as aluminum. The result is a frame that has a better ride than aluminum, but weighs more. It doesn't ride as well as steel, but it is lighter."

    That's all BS. Ti is stronger than steel,rides just as well,and can be about as light as alum.

    "I still hold that a modern steel bike built with hand-made cross-three wheels and good tires inflated to a maximum of 110 psi remains the gold standard. No other bike will ride as well."

    I only read the Aluminum and the Steel portion of this document...

    I guess you're right! That crap about Ti is totally BS! Sorry about that!

    However, I must thank you for the correction...

    Thanks, Dynaryder!

  16. #41
    Senior Member TransitBiker's Avatar
    Join Date
    Apr 2014
    Location
    Newtown, PA
    My Bikes
    2012 Breezer Uptown Infinity
    Posts
    1,254
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    If it broke clean it must have been improperly welded or improperly formed into a tube at the factory. I have seen alu and steel get shear breaks due to improper cooling, including 3 inch thick bar and pipes with quarter inch wall thickness that had just been installed or mid-installation.

    I am guessing it is a forming defect from factory, not welding, and not seat mount height.

    - Andy
    I can't wait for the next pint of good chocolate milk after a long ride.

  17. #42
    Senior Member
    Join Date
    Jun 2012
    Location
    SF Bay Area
    My Bikes
    2012 Specialized Sirrus
    Posts
    1,106
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Novara Buzz
    http://treadrightly.blogspot.com/

  18. #43
    Senior Member
    Join Date
    Sep 2012
    Location
    6367 km away from the center of the Earth
    Posts
    1,070
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cycle_maven View Post
    The Wikipedia graphic is just plain wrong. Fatigue life for carbon fiber is nearly infinite unless it is damaged. Also, "ride quality" is a pretty subjective quantity and depends more on the construction than the material used. It looks like a promo graphic for a titanium bike frame company.

    Yep. I chose communication over science. Not much we can extract from the over simplified chart. (nor from the OP case neither)

    I have a graph just for you




    The fatigue life for carbon fiber isn't infinite but roughly just higher. (depends on which one though)


    Even then there is lots of factors to take into account. What about the type of process used, build quality, frame design, under which load the bike is and where, how old the bike is (a 1976 steel bike vs a 2012 carbon bike), freeze-thaw cycle, riding type, corrosion resistance, shocks/cracks...

    Probably the reason why in real life, it seems that there is some catastrophic failures on the carbon fiber side as well. I was reading a thread not long ago that was asking a good question: why isn't much touring bikes made of carbon fiber?
    I was reading something recently about graphene that supposedly is better than anything else on the market (carbon nanotubes included) but isn't in real life due to imperfections than come with the current process used.
    http://news.rice.edu/2014/04/29/grap...-weakest-link/
    Last edited by erig007; 05-22-14 at 07:18 PM.

  19. #44
    Senior Member wolfchild's Avatar
    Join Date
    Feb 2008
    Location
    Mississauga/Toronto, Ontario canada
    My Bikes
    I have 3 singlespeed/fixed gear bikes
    Posts
    2,251
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    I have 2 steel framed bikes and one aluminium...My aluminium MTB has been beaten to death and it just keeps coming back to life.

  20. #45
    derailleurs are overrated bigbenaugust's Avatar
    Join Date
    Feb 2005
    Location
    KIGX
    My Bikes
    2009 Motobecane Fantom CX, 2012 Motobecane Fantom Cross Uno SSCX
    Posts
    1,735
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    You guys are making me flash back to my metallurgy days. STOP IT.

    --Ben
    Carrboro Bike Coalition - putting the "bike" in "CARrboro" :)
    2011 Motobecane Fantom Cross Uno, 2009 Motobecane Fantom CX
    Previously: 2000 Trek 4500 (2000-2003), 2003 Novara Randonee (2003-2006), 2003 Giant Rainier (2003-2008), 2005 Xootr Swift (2005-2007), 2007 Nashbar 1x9 (2007-2011), 2011 Windsor Shetland (2011-2014)
    Current Linux Usage (by machine): Arch: I openSUSE: III

  21. #46
    Senior Member Duane Behrens's Avatar
    Join Date
    Mar 2010
    Location
    Minnesota and Southern California
    My Bikes
    2009 Specialized Tarmac (CF), 1980 Nishiki (steel), 1984 Raleigh Super Course (steel), 1988 Schwinn World Sport (steel), 2009 Sp. Roubaix (carbon)
    Posts
    543
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by cycle_maven View Post
    The Wikipedia graphic is just plain wrong. Fatigue life for carbon fiber is nearly infinite unless it is damaged. Also, "ride quality" is a pretty subjective quantity and depends more on the construction than the material used. It looks like a promo graphic for a titanium bike frame company.
    Not to mention the tires. An $11,000, Dura-ace-everything, racing-specific, pure-carbon bike

    on 1 1/4" Shrader-valved tires

    will ride like a dream.

    Heh.
    The biggest fools are those who cannot suffer fools gladly. -Perzuki

  22. #47
    Senior Member TransitBiker's Avatar
    Join Date
    Apr 2014
    Location
    Newtown, PA
    My Bikes
    2012 Breezer Uptown Infinity
    Posts
    1,254
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by bigbenaugust View Post
    You guys are making me flash back to my metallurgy days. STOP IT.

    Shot weld for stainless steel?

    - Andy
    I can't wait for the next pint of good chocolate milk after a long ride.

  23. #48
    Senior Member catonec's Avatar
    Join Date
    Apr 2009
    Location
    burlington VT.
    Posts
    2,227
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    So I agree about the user being at fault and not the frame. but that doesnt really matter any more does it.

    check this out, steel frame, carbon fork, 105

    Save Up To 60% Off Pro Level Steel Road Bikes | Commuting | Commuter Bikes | Motobecane Gran Premio PRO
    2010 Kestrel RT900SL, 800k carbon, chorus/record, speedplay, zonda
    1997 Trek ZX6000, 6061w/manitou spyder, xt/xtr, time atac

  24. #49
    Senior Member megalowmatt's Avatar
    Join Date
    Jun 2009
    Location
    North County San Diego
    Posts
    1,555
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    This thread is like Thanksgiving dinner with the in laws.

  25. #50
    Senior Member
    Join Date
    Jan 2011
    Location
    pdx
    My Bikes
    2007 carpe diem frame custom build, trek 7.9 frame custom build, custom built chinese carbon fiber road bike, shopping bike
    Posts
    2,774
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Sullalto View Post
    So, like the subject says: what are some cheap($400-1000) steel framed bike?

    Would prefer a complete bike, but a build isn't totally out of the question.

    I only have one bike, a comfort bike that I bought for myself last Christmas. And the seat tube just broke cleanly, right above where the seat stays meet it.

    It's an alarming experience, I don't recommend it.

    So if decided: no more aluminum bikes. I want the more forgiving failure quality of steel.

    I'm only aware of Jamis' steel bikes-they have a steel hybrid, and a steel road bike line. What other manufacturers make steel bikes these days?

    I know to look at touring bikes, but I'm wondering if anything else is out there.

    Thanks!
    I've owned 13 bikes over the years. 4 frames failed when the down tube weld cracked and 1 had a cracked head tube. 3 were alu and 2 were steel. I've owned 4 crabon bikes and so far have not had a single crabon frame failure. In fact, I am certain that I will never have a carbon fiber frame fail due to normal fatigue.
    Road rash is a precious gift. Road rash is your friend. Bask in it, appreciate it, love it. Above all, learn from it. --Robert Hurst

Page 2 of 5 FirstFirst 1234 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •