Results 1 to 15 of 15

Thread: 1971 /5 Krauser Bag Frame Weld Repair

  1. #1
    Motomark motomark's Avatar
    Join Date
    Jul 2007
    Location
    Clyde N.C.
    Posts
    52

    1971 /5 Krauser Bag Frame Weld Repair

    The tubular frame on my /5 that holds R/H Krauser bag has a tab that holds the tail rack on it that needs to be welded where a stress crack has formed.My inquiry is what is the best kind of weld for this type of repair?Not too sure what kind of metal was used.I have the black painted type of carrier so I cant see under the paint to determine if its steel or a alloy.I do know that where the stress crack is it has rust on some of the cracked surface.Would appreciate any input,don't want to use wrong kind of weld and cause a worse problem.
    Thanks
    Mark

    1971 R75/5,1990 K75RT,1994 K75,1999 KLR

  2. #2
    Sir Darby Darryl Cainey's Avatar
    Join Date
    Mar 2003
    Location
    Fenwick, Ontario Canada
    Posts
    2,294
    I think most of the racks were Braised with bronze.

    Any competent welder should be able to do this!
    Ambassador BMW MOA Ontario Canada
    President Niagara BMW Riders #298
    Knights of the Roundel #333
    1977 R100RS, (Retired) 1993 R100GS (just getting started)

  3. #3
    Registered User lmo1131's Avatar
    Join Date
    Jan 2010
    Location
    Pismo Beach, CA
    Posts
    3,307
    "Alloy" (aluminum) doesn't rust.

    As Darryl stated, they're steel, and brazed. In my experience, once something has been brazed, it will have to be brazed if it needs repair; the brass and flux penetrates and contaminates the steel making it a PITA to "weld".

    I'd suggest pulling the whole rig off the bike and having the frames bead, or media, blasted to see if there are any other cracks starting to develop. When I bought my Krausers (used) I was going to have them stripped and powder coated. Once the powder-coater got the old finish off we found a couple of "iffy" joints.

    Post a few shots if you have time. I'm curious as to what "vintage" your hardware is. Duane Ausherman maintains a "Krauser" thread, and he's always looking for images.

    "It is what you discover, after you know it all, that counts." _ John Wooden

    Lew Morris
    1973 R75/5 - original owner

  4. #4
    R100GS, '89 Guenther's Avatar
    Join Date
    Jan 2007
    Location
    Colorado Springs, CO
    Posts
    481
    I have a friend who has a muffler shop. The welder there just used a grinder to strip off the paint and put some "blobs" on it. I painted it over with black paint. Holds just find and I can't even remember how long ago this was done.

    /Guenther

  5. #5
    Monza Blue 1974 R90/6
    Join Date
    Dec 2006
    Location
    Delaware
    Posts
    448
    Lew, is that your rack in the picture you posted? Looks like mine (except I have chrome), but I never knew what brand it was. I have BMW city cases.

    Barron

  6. #6
    Registered User
    Join Date
    Dec 2012
    Posts
    1,157

    My 2 cents

    I have the exact frame, and someone before me "brazed" it in several places - appeared to be whoever had it before me carried something on the back "deck" and they put in some supports.

    When I cleaned off a ton of paint, I found a hairline crack at the point where it attaches to the behind-the-seat frame mount.

    My suggestion: don't braze, but have it tig welded. Much nicer job, cleaner looking, and stronger. Once you braze, which isn't that strong, you will never be able to weld anywhere near it.

  7. #7
    Registered User lmo1131's Avatar
    Join Date
    Jan 2010
    Location
    Pismo Beach, CA
    Posts
    3,307
    Yeah Barron, my rack.

    Jimmy, I agree, TIG puts much less heat into the structure than brazing would.

    I've seen some Krauser hardware that looked "welded" (by virtue of the size and shape of the bead) ... maybe they switched at some point (?)
    "It is what you discover, after you know it all, that counts." _ John Wooden

    Lew Morris
    1973 R75/5 - original owner

  8. #8
    Motomark motomark's Avatar
    Join Date
    Jul 2007
    Location
    Clyde N.C.
    Posts
    52
    Quote Originally Posted by lmo1131 View Post
    "Alloy" (aluminum) doesn't rust.

    As Darryl stated, they're steel, and brazed. In my experience, once something has been brazed, it will have to be brazed if it needs repair; the brass and flux penetrates and contaminates the steel making it a PITA to "weld".

    I'd suggest pulling the whole rig off the bike and having the frames bead, or media, blasted to see if there are any other cracks starting to develop. When I bought my Krausers (used) I was going to have them stripped and powder coated. Once the powder-coater got the old finish off we found a couple of "iffy" joints.

    Post a few shots if you have time. I'm curious as to what "vintage" your hardware is. Duane Ausherman maintains a "Krauser" thread, and he's always looking for images.

    Lew,
    Thanks for the reply.My luggage carrier looks similar to the photo you posted,but is a three piece assembly.R&L halves bolted to the rearsubframe and center mounted rear rack that attaches to the R&L halves.Has BMW stamped on end that connects to upper shock mount bolt.I will use a dremel with a wire brush and remove the paint around the stress crack and nearby weld and see what color the weld is.I guess a brazed joint will be a brass color.
    Mark

    1971 R75/5,1990 K75RT,1994 K75,1999 KLR

  9. #9
    Registered User lmo1131's Avatar
    Join Date
    Jan 2010
    Location
    Pismo Beach, CA
    Posts
    3,307
    I guess a brazed joint will be a brass color.
    That is correct.

    "It is what you discover, after you know it all, that counts." _ John Wooden

    Lew Morris
    1973 R75/5 - original owner

  10. #10

  11. #11
    Registered User
    Join Date
    Dec 2012
    Posts
    1,157
    I have the same bag frames as pictured, and when paint was stripped, they were full of cracks. Previous owner(s) had tried to have brazed and then covered up the mess with extra-thick paint.

    I stripped mine, ground off all erratic welds, and ground out all the brazing.

    What I did, was to come up with some thoughtful supporting and cut pieces to look nice with nice fits. Then, I had TIG welded, but then did some MIG myself. ground, polished, and then re-painted. I suspect they will never break again. I do not, however, use them for a back bag or rack just behind the seat, just use for Krauser side bags.

    IMO, this design of the racks was suspect from the get-go. The metal is so flimsy and also soft (probably because the designers thought the frames would "give" but not break). However the design was awful! Nearly everyone I know has had to have them welded/brazed, etc.

    Final opinion, do not braze as it will cause problems later on and will then preclude welding altogether.
    "The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers

  12. #12
    Outlander Omega Man's Avatar
    Join Date
    Jan 2010
    Location
    Mansfield,MA
    Posts
    8,174
    Quote Originally Posted by jimmylee View Post
    Final opinion, do not braze as it will cause problems later on and will then preclude welding altogether.
    Like soldering, welding is best done with the metal clean. It is a bugger to remove brazing. There is a place for it but not here IMO.
    One thing I have noticed welding on my F800 parts, the German paint is really attached- and stinky.
    OM
    "Well they say.. time loves a hero but only time will tell.. If he's real, he's a legend from heaven If he ain't he was sent here from hell" Lowell George
    Mod Squad
    2009 F800GS 1994 TW200

  13. #13
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Location
    Albuquerque, NM
    Posts
    5,263
    Quote Originally Posted by jimmylee View Post
    IMO, this design of the racks was suspect from the get-go. The metal is so flimsy and also soft (probably because the designers thought the frames would "give" but not break). However the design was awful! Nearly everyone I know has had to have them welded/brazed, etc.
    BMW gets blamed for all sorts of things all the time and almost always this is wrong.

    For the most part, broken bag racks are simply evidence the bags have been overloaded. The specs are clear.

    No argument the specs are pretty low and I suspect I never left on a trip with them fully loaded when the weight wasn't over specification. Not much for washboard roads either.
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  14. #14
    Registered User
    Join Date
    Mar 2007
    Posts
    441
    On brazing vs welding--if the part was originally brazed with brass/bronze weld, you need to stick with this for repair. It you attempt to weld, be it TIG, MIG or oxy-acetylene, you will develop liquid metal embrittlement cracks.

  15. #15
    Registered User
    Join Date
    Dec 2012
    Posts
    1,157
    Quote Originally Posted by lkchris View Post
    BMW gets blamed for all sorts of things all the time and almost always this is wrong.

    For the most part, broken bag racks are simply evidence the bags have been overloaded. The specs are clear.

    No argument the specs are pretty low and I suspect I never left on a trip with them fully loaded when the weight wasn't over specification. Not much for washboard roads either.
    That's like trying to defend the design because it's stated capacity is 5 lbs. (or whatever light limit per your statement) when everyone knows using them for their stated purpose will ultimately overload them in normal use.

    Just face it. This was just a simply poor design (whether they stated limits or not) and could easily have been designed so this cracking and breaking would never have happened.

    The design should have been aborted!!

    Perhaps they will design a 1,000 cc motorcycle and state that one should not go over 20 mph. (just to cover their a$$$$$).
    "The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers

Tags for this Thread

Posting Permissions

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