more mechanical questions

Discussion in 'Recumbent bicycles' started by Joshua Goldberg, Jan 28, 2003.

Thread Status:
Not open for further replies.
  1. Okay...I am now virtually tool free (none left) and all I have left is to spread the rear triangle
    of the trike about 1.5 inches (further/farther) apart than stock. I have no idea how to spread the
    rear triangle (where the dropouts are). Question: if I used a Blow Torch to warm up the 4130 steel
    and just used brute strength and pryed the sucker apart and stuck in the axle...ya think the frame
    will crack when it gets cold again? There is some flex in the steel now, but not enough when the
    steel is cold and I suspect brittle. Any ideas?
     
    Tags:


  2. "Joshua Goldberg" skrev...
    > Okay...I am now virtually tool free (none left) and all I have left is to spread the rear triangle
    > of the trike about 1.5 inches (further/farther) apart than stock. I have no idea how to spread the
    > rear triangle (where the dropouts are). Question: if I used a Blow Torch to warm up the 4130 steel
    > and just used brute strength and pryed the sucker apart and stuck in the axle...ya think the frame
    > will crack when it gets cold again? There is some flex in the steel now, but not enough when the
    > steel is cold and I suspect brittle. Any ideas?

    Heard of one who used the jack from his car and carefully spread it that way. Used it on the Zox
    homebuilt.

    Mikael
     
  3. A Jack would work....good heavy iron, not possible for me to break
    it...sounds good to me, will try that thanx.

    "Mikael Seierup" <[email protected]> wrote in message
    news:[email protected]...
    >
    > "Joshua Goldberg" skrev...
    > > Okay...I am now virtually tool free (none left) and all I have left is
    to
    > > spread the rear triangle of the trike about 1.5 inches (further/farther) apart than stock. I
    > > have no idea how to spread the rear triangle (where the dropouts are). Question: if I used a
    > > Blow Torch to warm up the 4130 steel and just used brute strength and pryed the sucker apart and
    > > stuck in the axle...ya
    think
    > > the frame will crack when it gets cold again? There is some flex in the steel now, but not
    > > enough when the steel is cold and I suspect brittle.
    Any
    > > ideas?
    >
    > Heard of one who used the jack from his car and carefully spread it that
    way.
    > Used it on the Zox homebuilt.
    >
    > Mikael
     
  4. "Joshua Goldberg" skrev...
    > A Jack would work....good heavy iron, not possible for me to break
    > it...sounds good to me, will try that thanx.

    His website is here if you want to ask him about the specifics before trying.
    http://hjem.get2net.dk/mogens_skov/

    Mikael
     
  5. Derral

    Derral Guest

    Any 41XX series steel must be cooled very slowly after heating, else it will become brittle and
    break. (sometimes it will explode if cooled rapidly). If heated to red hot, (1100+ degrees F.) it
    should be cooled over about an 8-10 hour period. Wrap the heat affected areas in a fiber glass
    blanket and allow to sit over night, you might be able to use some of the pink ceiling insulation
    without the paper backing.

    "Joshua Goldberg" <[email protected]> wrote in message
    news:[email protected]...
    > Okay...I am now virtually tool free (none left) and all I have left is to spread the rear triangle
    > of the trike about 1.5 inches (further/farther) apart than stock. I have no idea how to spread the
    > rear triangle (where the dropouts are). Question: if I used a Blow Torch to warm up the 4130 steel
    > and just used brute strength and pryed the sucker apart and stuck in the axle...ya think the frame
    > will crack when it gets cold again? There is some flex in the steel now, but not enough when the
    > steel is cold and I suspect brittle.
    Any
    > ideas?
     
  6. Chris Walker

    Chris Walker Guest

    The Oracle seems to favour bending cold:

    http://www.sheldonbrown.com/frame-spacing.html

    Chris

    "Joshua Goldberg" <[email protected]> wrote in message
    news:<[email protected]>...
    > Okay...I am now virtually tool free (none left) and all I have left is to spread the rear triangle
    > of the trike about 1.5 inches (further/farther) apart than stock. I have no idea how to spread the
    > rear triangle (where the dropouts are). Question: if I used a Blow Torch to warm up the 4130 steel
    > and just used brute strength and pryed the sucker apart and stuck in the axle...ya think the frame
    > will crack when it gets cold again? There is some flex in the steel now, but not enough when the
    > steel is cold and I suspect brittle. Any ideas?
     
  7. Dax

    Dax Guest

    "derral" <[email protected]> wrote in message news:<[email protected]>...
    > Any 41XX series steel must be cooled very slowly after heating, else it will become brittle and
    > break. (sometimes it will explode if cooled rapidly). If heated to red hot, (1100+ degrees F.) it
    > should be cooled over about an 8-10 hour period. Wrap the heat affected areas in a fiber glass
    > blanket and allow to sit over night, you might be able to use some of the pink ceiling insulation
    > without the paper backing.
    >
    >
    > "Joshua Goldberg" <[email protected]> wrote in message
    > news:[email protected]...
    > > Okay...I am now virtually tool free (none left) and all I have left is to spread the rear
    > > triangle of the trike about 1.5 inches (further/farther) apart than stock. I have no idea how to
    > > spread the rear triangle (where the dropouts are). Question: if I used a Blow Torch to warm up
    > > the 4130 steel and just used brute strength and pryed the sucker apart and stuck in the
    > > axle...ya think the frame will crack when it gets cold again? There is some flex in the steel
    > > now, but not enough when the steel is cold and I suspect brittle.
    > Any
    > > ideas?
    > >
    > >

    I would NOT heat it (that's why they call it 'cold-setting). Get two 4' pieces of say 1"x4" plank.
    Remove wheel, stand behind bike, slide planks together into r. triangle along line of chainstay. Now
    pry'em apart. Stays will spread evenly. IMPORTANT: make sure the dropouts face each other squarely
    if you don't want a lot of busted axles. Take two old axles and run the nuts in so they can each sit
    in a dropout facing each other, kissing. Get them to line up! You should also check tracking by
    running a thread from dropout-to-head-tube-to-dropout and measuring with calipers at whatever passes
    for a seat tube in yr frame design. Don't pop any welds - Ъ×
     
  8. Geob

    Geob Guest

    > it should be cooled over about an 8-10 hour period.

    I assume you know a whole lot more about his metal than I do. Unless I knew different specifically,
    I might have a tendency to think that heating it would cause/allow any dislocations in the metal
    introduced when cold-worked at manufacturing time (which add strength and reduce ductility), to
    'anneal'. This process allows the metal to re-form in a more relaxed state which yields a much
    milder material with a great deal fewer dislocation in the atomic structure of the metal, which will
    bend much easier. Like a coat-hanger that has been through a fire.

    I sure wouldn't heat mine, but I am a newbie and I don't pretend to know all of the answers. Nor am
    I wise enough to sit quietly till I do know the answers!

    GeoB :)

    Prov 10:19 "When there are many words, trangression is unavoidable, but he who restrains his
    lips is wise"
     
  9. Derral

    Derral Guest

    Right, the anneal process comes from heating and cooling at a slow rate. Cold working 41xx steel
    will create a hard, brittle material. This material is used to manufacture oil drill string
    components, it's not uncommon for the thread connections to harden to a Rockwell C scale of 45-50
    after severe drilling conditions where there is a lot of flex in the drill string. These have to be
    annealed back to about a 28-36 hardness to prevent breakage.

    I was not advocating heating a bicycle frame, just stating what I know about what happens to
    Chrome-Moly steel when it is heated.

    "GeoB" <[email protected]> wrote in message news:[email protected]...
    > > it should be cooled over about an 8-10 hour period.
    >
    > I assume you know a whole lot more about his metal than I do. Unless I knew different
    > specifically, I might have a tendency to think that heating it would cause/allow any dislocations
    > in the metal introduced when cold-worked at manufacturing time (which add strength and reduce
    > ductility), to 'anneal'. This process allows the metal to re-form in a more relaxed state which
    > yields a much milder material with a great deal fewer dislocation in the atomic structure of the
    > metal, which will bend much easier. Like a coat-hanger that has been through a fire.
    >
    > I sure wouldn't heat mine, but I am a newbie and I don't pretend to know all of the answers. Nor
    > am I wise enough to sit quietly till I do know the answers!
    >
    > GeoB :)
    >
    > Prov 10:19 "When there are many words, trangression is unavoidable, but he who restrains his lips
    > is wise"
     
  10. Okay Already Seems my Triangle was NOT my only problem. I did spread the triangle apart using the 2
    Wood Plank suggestion (it worked well...thanks). Glitch #2 appeared, the Axle is 1/5th inch larger
    in Diameter than are the dropouts and since I already fried my Dremel, am going to have to find a
    metal file and widen the dropouts Thursday morning. Can it get any worse??...I have a box of these
    new axles and every frame I tried appears to have dropouts too small....hmmm guess this is why the
    axles were on sale. What is the line again about there being one new one being born every minute.
    ----------------------------------------------------------------------------
    ------------------------------
    "derral" <[email protected]> wrote in message news:[email protected]...
    > Right, the anneal process comes from heating and cooling at a slow rate. Cold working 41xx steel
    > will create a hard, brittle material. This material is used to manufacture oil drill string
    > components, it's not uncommon for the thread connections to harden to a Rockwell C scale of
    45-50
    > after severe drilling conditions where there is a lot of flex in the drill string. These have to
    > be annealed back to about a 28-36 hardness to prevent breakage.
    >
    > I was not advocating heating a bicycle frame, just stating what I know
    about
    > what happens to Chrome-Moly steel when it is heated.
    >
    > "GeoB" <[email protected]> wrote in message news:[email protected]...
    > > > it should be cooled over about an 8-10 hour period.
    > >
    > > I assume you know a whole lot more about his metal than I do. Unless I knew different
    > > specifically, I might have a tendency to think that heating it would cause/allow any
    > > dislocations in the metal introduced when cold-worked at manufacturing time (which add
    > > strength and reduce ductility), to 'anneal'. This process allows the metal to re-form in a
    > > more relaxed state which yields a much milder material with a great deal fewer dislocation in
    > > the atomic structure of the metal, which will bend much easier. Like a coat-hanger that has
    > > been through a fire.
    > >
    > > I sure wouldn't heat mine, but I am a newbie and I don't pretend to know all of the answers. Nor
    > > am I wise enough to sit quietly till I do know the answers!
    > >
    > > GeoB :)
    > >
    > > Prov 10:19 "When there are many words, trangression is unavoidable, but he who restrains his
    > > lips is wise"
     
Loading...
Thread Status:
Not open for further replies.
Loading...