Advertise on Bikeforums.net



User Tag List

Page 1 of 3 123 LastLast
Results 1 to 25 of 71
  1. #1
    Junior Member
    Join Date
    Aug 2012
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    EMERGENCY Frame Repair (worst I've ever SEEN!)

    I have a Giant Lite LA Free Electric Bicycle.

    So where my down tube meets the bottom bracket (well what's actually the top of my engine), has snapped. Not cracked. SNAPPED. OFF. Right now I'm just dealing with getting all the plastic guards off the engine/frame, and taking the crank arm off. Afterwards, I have JB Weld epoxy putty. I don't know what the best way to use it is, or if it's the best thing to use at all. Any tips?

    Also, when I actually get it permanently welded, will I have to take the whole engine off? I need help!!

  2. #2
    http://www.538.nl acidfast7's Avatar
    Join Date
    Jul 2010
    Location
    England / CPH
    My Bikes
    2010 Cube Acid
    Posts
    4,989
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    frame warranty would be the first step.
    Movimento 5 Stelle (M5S)
    Rohloffs seen on the commute: 3

  3. #3
    Senior Member
    Join Date
    May 2010
    Location
    Madison, WI
    Posts
    1,094
    Mentioned
    1 Post(s)
    Tagged
    1 Thread(s)
    Use JB weld if you would like to wake up in a hospital in the near future.

    If the frame is alloy, it's not safe to weld either.

  4. #4
    Foward Leaning Attitude rithem's Avatar
    Join Date
    Mar 2005
    Location
    RHODE-MF-ISLAND
    Posts
    851
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by acidfast7 View Post
    frame warranty would be the first step.
    +1 sounds like a lost cause bring to the dealer where it was purchased. See where to go from there.

    /thread

  5. #5
    Gammal cyklist Reynolds's Avatar
    Join Date
    Jul 2005
    My Bikes
    1998 Pinarello Asolo, 1992 KHS Montaņa pro, 1980 Raleigh DL-1, IGH Hybrid, IGH Utility
    Posts
    4,447
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Replace that frame, don't repair it.

  6. #6
    Senior Member gforeman's Avatar
    Join Date
    Jun 2008
    Location
    Northern Virginia
    My Bikes
    Specialized Roubaix SL4 Expert, Specialized Crux Disc
    Posts
    727
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    JB Weld, is really not a "WELD" It's an Epoxy, and a disaster waiting to happen if you use it on a frame. JBW is great for some things, but I would never trust it on something like a frame.
    Gary F.


    2015 Specialized Roubaix SL4 Expert
    2012 Specialized Crux Disc
    My bike page: http://www.gwfweb.com/bicycles
    Build a bike stand! http://www.gwfweb.com/bicycles/stands.html

  7. #7
    Mechanic/Tourist
    Join Date
    Apr 2007
    Location
    Syracuse, NY
    My Bikes
    2008 Novara Randonee - love it. Would have more bikes if I had time to ride them all. Previous bikes: 1968 Motobecane Mirage, 1972 Moto Grand Jubilee (my fav), Jackson Rake 16, 1983 C'dale ST500.
    Posts
    4,932
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Giant Bicycle, Inc. ("Giant") warrants the frame and rigid fork of each new Giant brand bicycle and Giant brand frameset to be free from defects in material and workmanship for as long as the original purchaser owns the bicycle. ALL WARRANTIES ARE VOID IF THE BICYCLE IS MODIFIED FROM ITS ORIGINAL CONDITION OR THE BICYCLE IS USED FOR OTHER THAN NORMAL ACTIVITIES, INCLUDING, BUT NOT LIMITED TO, FAILING TO FOLLOW THE OWNER'S MANUAL OR USING THE BICYCLE FOR COMMERCIAL ACTIVITIES OR IN COMPETITIVE EVENTS, INCLUDING BUT NOT LIMITED TO BICYCLE RACING, BICYCLE MOTOCROSS RACING, STUNT RIDING, RAMP JUMPING OR SIMILAR ACTIVITIES, AND TRAINING FOR SUCH ACTIVITIES OR EVENTS.

    http://www.giant-bicycles.com/en-us/page/175/#question2
    There's no such thing as a routine repair.

    Don't tell me what "should" be - either it is, it isn't, or do something about it.

    If you think I'm being blunt take it as a compliment - if I thought you were too weak to handle the truth or a strong opinion I would not bother.

    Please take the time to post clearly so we can answer quickly. All lowercase and multiple typos makes for a hard read. Thanks!

  8. #8
    Senior Member JTGraphics's Avatar
    Join Date
    Dec 2006
    Location
    So Cal
    Posts
    2,508
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I don't understand why people insist on using JB Weld to fix cracks on frames like it's really going to hold?

    JB Weld big no vote from me.
    Last edited by JTGraphics; 08-27-12 at 09:23 AM.
    It may not be fancy but it gets me were I need to go.
    http://www.jtgraphics.net/cyclist_bicycles.htm

  9. #9
    incazzare. lostarchitect's Avatar
    Join Date
    Mar 2010
    Location
    Brooklyn, NY
    My Bikes
    See sig
    Posts
    4,181
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Another no on JB Weld. Very bad idea.

    See if the frame is under warranty and get a replacement.
    1964 JRJ (Bob Jackson) San Remo Plus, 1989 Trek 520, 2000ish Colian (Colin Laing), 2013 Velo Orange Pass Hunter

  10. #10
    Lover of Old Chrome Moly Myosmith's Avatar
    Join Date
    May 2011
    Location
    NW Minnesota
    Posts
    2,544
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    JB weld is nothing but epoxy filled with aluminum powder. Despite some of the claims made for the product, it's just glue/filler and in no way a replacement for metal.
    Lead, follow or get out of the way

  11. #11
    Senior Member
    Join Date
    Jun 2007
    Posts
    151
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Myosmith View Post
    JB weld is nothing but epoxy filled with aluminum powder. Despite some of the claims made for the product, it's just glue/filler and in no way a replacement for metal.
    It does make a very good bedding agent for *****s though.

  12. #12
    Senior Member Chombi's Avatar
    Join Date
    Jul 2009
    Posts
    9,353
    Mentioned
    12 Post(s)
    Tagged
    0 Thread(s)
    I cannot really see any place on a bicycle where you can safely use JB Weld on, as mot items on the bike are stressed/structural.
    On the other hand, JB Weld works best for just filling holes like on cracked or holed motorcycle side engine cases that usually is a reault of a dropped or crashed motorcycle. Basically just to keep the oil in the engine in such cases, but nothing really structural. Even then, most regard such fixes are temporary and the part should really be replaced asap as I suspect that the heat cycles an engine goes through would eventually loosen up any JB Weld patches.

    Chombi

  13. #13
    Junior Member
    Join Date
    Aug 2012
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Nerull View Post
    Use JB weld if you would like to wake up in a hospital in the near future.

    If the frame is alloy, it's not safe to weld either.
    So is it generally agreed that I can't get it welded either? I've already spoken to multiple welders and it doesn't sound like it's going to be a problem. So I'm not sure if you have room to be so sure of yourself, are you a welder? I think a welder with a cert only needs to know exactly what the alloy is to weld it.

    Also, I was really very clear on where the break is. If it snaps, I'm not going to fly off my bike. I didn't "wake up in a hospital" after it snapped initially.

    I think my point is, when you're replying to someone on the internet who needs a little help, you shouldn't be so rude and treat them like and idiot. Do you help to feel superior? How about helping for the sake of helping. Thank you.

  14. #14
    Junior Member
    Join Date
    Aug 2012
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Also, I would like to say that I'm using the JB Weld PUTTY not the glue. It is STEEL REINFORCED not just "glue and filler". Has anyone used anything other than "JB Weld" glue? This putty is used to repair American vehicles. I've seen it used to reinforce frames many times. I've seen epoxy resins used to BUILD BICYCLE FRAMES. People who build bamboo frames use epoxy putties and resins. Even companies such as Stalk bicycles use an epoxy system to build their bamboo frames.

    This is an aluminum frame, so I understand that it isn't the safest method. This is for a strictly temporary fix, until I either replace the frame or have it welded. The break is not in a very dangerous spot as far as my safety goes, just the safety of the cords that run into my engine.

  15. #15
    Senior member Dan Burkhart's Avatar
    Join Date
    Oct 2004
    Location
    Oakville Ontario
    Posts
    4,906
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Starscream View Post
    So is it generally agreed that I can't get it welded either? I've already spoken to multiple welders and it doesn't sound like it's going to be a problem. So I'm not sure if you have room to be so sure of yourself, are you a welder? I think a welder with a cert only needs to know exactly what the alloy is to weld it.

    Also, I was really very clear on where the break is. If it snaps, I'm not going to fly off my bike. I didn't "wake up in a hospital" after it snapped initially.

    I think my point is, when you're replying to someone on the internet who needs a little help, you shouldn't be so rude and treat them like and idiot. Do you help to feel superior? How about helping for the sake of helping. Thank you.
    ??? I saw no sign of rudeness in any of the responses. I have no idea why you would interpret the helpful responses above in such a manner.
    The advice was sound. Why the aversion to trying a warranty claim?
    Gearhubs demystified and other cool stuff.


    Rule #12: The correct number of bikes to own is n+1

  16. #16
    Senior Member gforeman's Avatar
    Join Date
    Jun 2008
    Location
    Northern Virginia
    My Bikes
    Specialized Roubaix SL4 Expert, Specialized Crux Disc
    Posts
    727
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Starscream View Post
    Also, I would like to say that I'm using the JB Weld PUTTY not the glue. It is STEEL REINFORCED not just "glue and filler".
    JBW Putty is no stronger than the other JBW. The putty just holds it's form better while setting up. STEEL REINFORCED means it has steel filler. There is no way it is going to harden into STEEL. And I'm not trying to be rude either, but I feel you are wasting your time and money if you think this will hold. Maybe a day, maybe a week, but the right bump, and you are going to have to clean it all off before a welder will even touch it.

    I agree with others, try the warranty route first.

    You asked and, you received a lot of opinions. You as the owner must weigh all this info and make a calculated decision. No one here thinks you are an idiot for asking. But if everyone tells you you shouldn't, and you do it anyway...
    Gary F.


    2015 Specialized Roubaix SL4 Expert
    2012 Specialized Crux Disc
    My bike page: http://www.gwfweb.com/bicycles
    Build a bike stand! http://www.gwfweb.com/bicycles/stands.html

  17. #17
    Senior Member
    Join Date
    Oct 2009
    Location
    Willy, VIC
    Posts
    598
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    You probably won't listen to this either, but here are some actual figures:

    Tensile strength of typical Aluminium alloy (6061 T6): 310 MPa.
    Tensile strength of same alloy after welding (no PWHT): 120 MPa
    Adhesion strength of JB Weld: 12 MPa


    The frame is toast.

  18. #18
    Senior Member JTGraphics's Avatar
    Join Date
    Dec 2006
    Location
    So Cal
    Posts
    2,508
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    All I can say is you asked you got some great answers, if you are going to do as you like than go ahead use your method and I say good luck.
    I know quite a few like you who ask question and advice and still do as they want and regret it later.
    So keep safe thats all I can say to this thread.
    It may not be fancy but it gets me were I need to go.
    http://www.jtgraphics.net/cyclist_bicycles.htm

  19. #19
    Lover of Old Chrome Moly Myosmith's Avatar
    Join Date
    May 2011
    Location
    NW Minnesota
    Posts
    2,544
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Actually, yes, I do have welding experience. My father ran an automotive and machinery restoration business and I've welded, silver soldered and brazed parts for valuable antique vehicles as well as having done custom automotive body and fame work. I also made custom knives, both art and working pieces, and have a decent understanding of metallurgy. I have used JB weld numerous times for a variety of purposes and as I stated, the JB Weld putty or paste is nothing more than epoxy with a metalic filler. Epoxy can and has been used to build bicycle frames, carbon fiber bikes are entirely fiber reinforced resin. That is a far cry from sticking two pieces of structural aluminum together with epoxy putty.

    The people here are trying to help you. If you don't think we know what we are talking about, feel free to take your question to the framebuilder's forum and ask it there.

    There are many welders who work with aluminum, both of my stepsons are experienced welders, one of whom worked for an aluminum truck box manufacturer as a lead welder and the other works at a company that contracts to produce military equipment. Both are qualified in variety of specialty welding applications, including aluminum. Can an aluminum frame be repaired, sure, but you would not only have to get the joint welded, you would also have to stress relieve the frame to prevent brittleness that could lead to later cracking. As mentioned, you probably have a warranty claim for a new frame that will also be under warranty. That goes out the window the second anyone else tries to weld or glue the frame back together.

    Do what you like. Good luck to you.
    Lead, follow or get out of the way

  20. #20
    http://www.538.nl acidfast7's Avatar
    Join Date
    Jul 2010
    Location
    England / CPH
    My Bikes
    2010 Cube Acid
    Posts
    4,989
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Starscream View Post
    Also, I would like to say that I'm using the JB Weld PUTTY not the glue. It is STEEL REINFORCED not just "glue and filler". Has anyone used anything other than "JB Weld" glue? This putty is used to repair American vehicles. I've seen it used to reinforce frames many times. I've seen epoxy resins used to BUILD BICYCLE FRAMES. People who build bamboo frames use epoxy putties and resins. Even companies such as Stalk bicycles use an epoxy system to build their bamboo frames.

    This is an aluminum frame, so I understand that it isn't the safest method. This is for a strictly temporary fix, until I either replace the frame or have it welded. The break is not in a very dangerous spot as far as my safety goes, just the safety of the cords that run into my engine.
    Good luck with your bicycle. Instead of discussing the merits of welding with us, why don't you call GIANT and let us know the result, so something useful can come out this thread.
    Movimento 5 Stelle (M5S)
    Rohloffs seen on the commute: 3

  21. #21
    Senior Member
    Join Date
    May 2010
    Location
    Madison, WI
    Posts
    1,094
    Mentioned
    1 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Starscream View Post
    So is it generally agreed that I can't get it welded either? I've already spoken to multiple welders and it doesn't sound like it's going to be a problem. So I'm not sure if you have room to be so sure of yourself, are you a welder? I think a welder with a cert only needs to know exactly what the alloy is to weld it.

    Also, I was really very clear on where the break is. If it snaps, I'm not going to fly off my bike. I didn't "wake up in a hospital" after it snapped initially.

    I think my point is, when you're replying to someone on the internet who needs a little help, you shouldn't be so rude and treat them like and idiot. Do you help to feel superior? How about helping for the sake of helping. Thank you.
    All alloy frames are heat treated. This is what makes them strong. This is done by putting the entire frame, before painting, in an oven for several hours at high temperatures.

    Welding will destroy the heat treatment and significantly compromise the structural integrity of the frame.

  22. #22
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,828
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    This:
    Quote Originally Posted by Mark Kelly View Post
    Tensile strength of typical Aluminium alloy (6061 T6): 310 MPa.
    Tensile strength of same alloy after welding (no PWHT): 120 MPa
    Adhesion strength of JB Weld: 12 MPa

    The frame is toast.
    And LOL

  23. #23
    Junior Member
    Join Date
    Aug 2012
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    FIRSTLY, I was pretty sure I stated the warranty is already void. The bicycle is discontinued. So you can stop with this "Contact Giant and let us know the result so we can laugh at you."
    I already know. This isn't the issue, I wasn't asking about information on the manufacturer.

    The words strictly temporary mean absolutely nothing, do they?
    I used two tubes of the highest quality steel reinforced putty I could find.
    I STRICTLY TEMPORARILY reinforced the break using one tube, layering a few steel mesh patches over it, then using the other tube over the patches. I added a few touches to reinforce it, all of which you holier than thou bicycle enthusiasts would probably make fun of.
    I've ridden it for almost 2 weeks every day for at least 2 miles, with some caution but not extreme caution.
    It's just now starting to crack.

    Epoxy putty is not all the same, and entirely depends on how it's used.

  24. #24
    I let the dogs out AlphaDogg's Avatar
    Join Date
    Apr 2011
    Location
    Boulder, CO
    My Bikes
    2011 Fuji Roubaix 1.0, 2003 Ti Merlin Solis, & 1994 Raleigh MT200
    Posts
    1,934
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Starscream View Post
    The words strictly temporary mean absolutely nothing, do they?
    Not when you become a stain on the pavement. Be smart about this.
    Quote Originally Posted by Andrew R Stewart View Post
    Weird spell/word check. "***" is "***". I'll never understand this computer. Andy.

  25. #25
    johnliu@earthlink.net jyl's Avatar
    Join Date
    Aug 2006
    Location
    Portland OR
    My Bikes
    61 Bianchi Specialissima 71 Peugeot G50 7? P'geot PX10 74 Raleigh GranSport 75 P'geot UO8 78? Raleigh Team Pro 82 P'geot PSV 86 P'geot PX 91 Bridgestone MB0 92 B'stone XO1 97 Rans VRex 92 Cannondale R1000 94 B'stone MB5 97 Vitus 997
    Posts
    3,803
    Mentioned
    40 Post(s)
    Tagged
    0 Thread(s)
    So your clever repair lasted for about 30 miles of gentle riding. Hardly sounds like a repair, not even an emergency one. Sounds like you fixed your frame about as well as a roll of duct tape would have done.

    When folks here tried to help you, they were probably assuming you wanted an actual repair, not a duct tape level of kludge.
    Your signature contains too many lines and must be shortened. You may only have up to 2 line(s). Long text may have been implicitly wrapped, causing it to be

Page 1 of 3 123 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
  •