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anyone here ever make their own lugs for building bikes?

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  • anyone here ever make their own lugs for building bikes?

    I seem to recall some guys on here who have done some bicycle building. I'm getting the urge to ride a real fat tire monster like the Surly Pugsley, and I think it would be cool to build a lugged frame for the Large Marge rims and some 3.8" tires. I don't see why I couldn't weld up my own lugs, but I'm just looking for any tips or gotchas to watch out for. I'd just be using 4130 for everything. I'd be using straight wall tubing for the frame instead of butted because I really don't think I need butted tubes if I use lugs. The tubes would be brazed into the lugs and not welded together, so my thought is I don't need the extra thickness at the tube ends. I may very well be wrong on that though.

    andy b.
    The danger is not that computers will come to think like men - but that men will come to think like computers. - some guy on another forum not dedicated to machining

  • #2
    Bicycle engineering forum:

    http://www.eng-tips.com/threadminder.cfm?pid=664

    Comment


    • #3
      I ride all the time and I build lots of bikes. Here are some pics of a few.

      This one is called a Low Racer. Wind resistance is 2/3 less that of an upright bike. I can pedal along fairly easy at 24 mph. If I pedal real hard I can get it up to 32 mph. It is a lot of run to ride. It has 24 speeds with 100 psi tires. I built 2 of these and I have frames for 3 more.



      http://i43.photobucket.com/albums/e3...Bike002-vi.jpg


      This is a very nice riding bike with 16 speed and high pressure tires. I did not built it for speed but I can pedal it 20 mph. I ride it a lot around town and I have a trailer that I build for hauling firewood, lumber, groceries, all sorts of things. I can haul 130 lbs of firewood on the trailer. I am in the process of putting a 20 gallon air tank on the trailer and a Locomotive Train horn in the bike. It is going to be fun to honk at people.





      This is a real fun bike to ride it is like driving a sport car. I is very manoverable and quick. It has 24 speeds and 100 psi high pressure tires. It has low wind resistance and if very fast. I built 2 of these. Seats on all the bikes are adjustable, seat slices forward and back for riders with long or short legs, back tilts forward and back too.




      This is another nice smooth riding bike I put over 1000 miles on it one summer then sold it. It has 24 speeds with 100 psi high pressure tires.






      This was a fun bike to ride my Son road it to high school for several years.

      http://i43.photobucket.com/albums/e3...350/trike1.jpg




      My Son use to ride this one to school sometimes too.

      http://i43.photobucket.com/albums/e3...y350/tall1.jpg



      I use to have 24 bikes that I built when my Son was young all the boys in the neighbor hood would come to our house Saturday morning, leave their bike and take one of mine. The whole group of about 11 boys spent the whole weekend riding bikes.
      Last edited by gary350; 12-08-2010, 09:55 AM.

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      • #4
        Yes, you can build your own lugs. Years ago I was going to build a tandem frame that way. At first I was going to try to TIG weld tube sections together, and cut and file them into lugs. But I found that TIG welding thin tubes takes the hands of a surgeon, and I didn't enough access to a welder (at weekly class sessions at a local school) to aquire that skill. Then I realized that I could brass braze the lugs together, and silver braze the frame tubes into them. About that time Tom Kellogg, one of the country's top framebuilders, did just that, and his frame wound up on the cover of Bicycle Guide magazine. Beautiful work. If I can find that old magazine I can post some scans, if you like. Also some photos of my lugs, as far as they got.

        If you want to make something nice, you'll want to use butted tube. The heat affected zone extends an inch or more back from the lug, and the tube is somewhat weaker there, so you need extra thickness there. The middle of the tube can be thinner.

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        • #5
          Why not just brass braze the tubes together? Making lugs usually involves brazing short tubes together for a slip-fit of the frame tubes and silver. Skip the extra work and expense. You can get all sorts of 4130 tube sizes from wicks and aircraft spruce, but even if you use straight gauge tubes, you still have to use at least .035 unless you are an experienced welder using hardened tubing. Steerer tubes are even thicker where the crown attaches.

          Henry James sells good flux and brass/silver, and he can offer plenty of advice. You can also get an idea of how thick the various tubes should be. Just be careful. I've seen the result of a frame coming apart.

          Lots of building info can be found here: http://forums.mtbr.com/forumdisplay.php?f=142
          My Flickr album

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          • #6
            Thanks for the replies!!!

            Thruthefence,
            I'm going to have a lot of reading to do on that link you posted.

            gary350,
            WILD designs!!!! Definitely post any tips you have (or other frames). Very cool!!! Are your frames all TIG welded? And I want to see that cart with the 130 lbs. of firewood on it.

            Randy,
            Thanks for the butted tube info. Looking around, it looks like most tubes are sold as double- or quad-butted anyway, so it looks like I'd be using something like that by default. I'd love to see photos of the lugs you were working on. I figure if I leave the tubes round where they enter the lugs, then my lathe should be able to do whatever ID I need for the lug pieces. Post the scans if you find the mag, I'd like to see it. Are there any mags dedicated to bike frame building? I never even thought to look into that.

            andy b.
            The danger is not that computers will come to think like men - but that men will come to think like computers. - some guy on another forum not dedicated to machining

            Comment


            • #7
              Originally posted by smudgemo
              Why not just brass braze the tubes together? Making lugs usually involves brazing short tubes together for a slip-fit of the frame tubes and silver. Skip the extra work and expense. You can get all sorts of 4130 tube sizes from wicks and aircraft spruce, but even if you use straight gauge tubes, you still have to use at least .035 unless you are an experienced welder using hardened tubing. Steerer tubes are even thicker where the crown attaches.

              Henry James sells good flux and brass/silver, and he can offer plenty of advice. You can also get an idea of how thick the various tubes should be. Just be careful. I've seen the result of a frame coming apart.

              Lots of building info can be found here: http://forums.mtbr.com/forumdisplay.php?f=142

              Yes, those buggers posting over at mtbr are what got me thinking about this. I originally went there to get some info on a few old Cannondales, and a guy mentioned his Pugsley project. Then at the local bike store two weeks ago they had a Pug on display. We go to the Outer Banks on vacation every year or so and I figured some of those Surly Endomorph tires would be great for sand at the beach, and snow behind my house. The guys in the frame builder forum on mtbr seem a bit harsh on newbies, so I figured I'd check with my buds here at HSM to get started.

              I just love the look of a lugged frame, mainly because it looks old, and I like anything old. I don't own a TIG welder, and I'm not sure how much I trust brazed tubing joints. Yes, it looks like lots of builders use them, but since I like the look of lugs, and I'm pretty good with welding fairly thin tubing with the MIG welder (not bike frame thin though), I figure I can MIG the lugs, and then braze the tubing in.

              andy b.
              The danger is not that computers will come to think like men - but that men will come to think like computers. - some guy on another forum not dedicated to machining

              Comment


              • #8
                Gary,

                That's quite the chain track on the first bike. How long does it take after you shift the front sprocket for the change to get back to the rear wheel?

                Seriously, very nice looking and interesting work.
                .
                "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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                • #9
                  Recumbent [spelling?] bikes with respect seem a little dangerous, only recently i saw a guy fall over at a traffic light, on UK narrow roads they look more successful than a Swiss suicide clinic.
                  Didnt Evan build a Hybrid, seem to remember somthing but even saying that they do look like a bit of a challenge to build, in most cases i would guess that a hard soldered or brazed 4130 with a goot tight set up would equal the strength of a tig welded tube or at least come close, at least brittle fracture would be less of a problem, unless of course you want an ali frame in which case tig is the only way [or glued bosses, i seem to remember an article in a mag about using epoxy resins to make bikes]
                  I have a couple of bike fanatics at work, they seem to spend an awful lot on saving grams on frame weight like titanium nuts and bolt and all sorts of carbon fibre bits, it seems they will pay a couple of thousand for a frame!, it tempts me to start building them!
                  mark

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                  • #10
                    You say you like lugs? Well, here is a site you must visit. You'll get lots of ideas for classic fancy lugs.
                    http://www.hetchins.org/

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                    • #11
                      Those are nice looking bikes, Gary.

                      I had a couple of other thoughts on this, Andy. The Pugs has a lot of engineering going on because of how wide the tires are, and it's going to be tough to figure all of that out. Chain clearance is the major issue.

                      Second, I recall a thread (probably on MTBR) about MIG, and that it wasn't really considered acceptable. I only use O/A and know nothing of MIG, just mentioning it. You won't get flamed if you use the search function before asking questions there.

                      Best of luck! It's really awesome to ride around on something you built, or take it to work and have the folks there scratch their heads at how anyone could actually build something from scratch.
                      Last edited by smudgemo; 12-08-2010, 09:11 AM.
                      My Flickr album

                      Comment


                      • #12
                        Originally posted by andy_b
                        Thanks for the replies!!!

                        gary350,
                        WILD designs!!!! Definitely post any tips you have (or other frames). Very cool!!! Are your frames all TIG welded? And I want to see that cart with the 130 lbs. of firewood on it.

                        I built an adjustable frame welding fixture. I start at the back wheel and mount the metal parts the correct wide to match the back wheel the bike will have. I cut out those pieces on the mill. Next I set the front axle distance between the 2 wheels also the axle height. Next I mount the steering fork in the fixture with the steering tube with bearings. The steering tube angle has to change according to the distance between the front and back axle other wise the bike will not steer correctly. The angle of the steering tube changes from 20 degrees for short wheel base to 33 degrees long wheel base. If you put a steep angle on a short wheel base bike steering is very quick and sensitive. Next I adjust the fixture to hold the pedal crank tube in the correct location. Now that all the parks in the fixture I measure between the parts, cut the tubes, mill half round places in the tube ends so they fit perfect to the part they will be welded to. I tack weld all the tubes in place. After all the tubes are in place then I weld everything using an old Lincoln stick welder using 3/32 7014 rods. If all the tubes fit perfect it is easy to weld. I can't weld any tubes with a wall thickness of less than .062". Next I grind all the welds smooth. Next the frame is cleaned, sanded, primed, and painted. In the summer I hang the frames in the hot attic 150 degrees for a week makes the paint hard as rock. Now the parts are ready to assemble to the bike.




                        Check out the video.

                        http://www.youtube.com/watch?v=OMGN94NVU3k
                        Last edited by gary350; 12-08-2010, 11:23 AM.

                        Comment


                        • #13
                          +1 on the fillet brazing idea...if you want the molded look as opposed to what you appear to be after (the fancy type of lug)

                          IIRC if the fancy lug is your choice, and you have LOTS of time, you can buy "blanks" that are longer than the norm and you can cut in whatever shape you want, often a makers logo for example

                          And this is one case where "cheap" works better since, again IIRC, many of the really fancy lugs are cast ("pre") and you then have to make the angles, with a very small allowance, exactly as cast or you will crack the casting. The "cheap" are more thick sheet metal factory welded together and have a large range of angles that can be accommodated at each joint. There needs to be some care with overall geometry of the design since you can effectively build yourself into a corner where either nothing matches or end up with characteristics of the finished frame that are the last thing you want (often "lazy" handling; "mine" tended to be the opposite since they were track bikes, you look at them and they turn)

                          Not knowing the model you refer to, you may find it difficult to find lugs of the size of tubes you want to use (they may be using something proprietary) which was the reason some went to fillet brazing back in the day. I could be horribly wrong but most lugs will come from SE Asia, people like Henry James and Kelllog may get some of theirs done locally but for the most part...and you may find it tough to get what you want unless you go through another established builders since, given what these pieces are, volume is an issue.

                          http://www.cycle-frames.com/bicycle-...YS-SERIES.html

                          is from Nova. Don't forget if you want all the bits and pieces matched, not all lugs sets can be "gotten" with matching bottom brackets and some lugs don't work with some other details (that you may or may not want to use). Once you start digging there are choices though that may require back and forth to Europe.

                          I would also suggest you do really want to go with butted tubing v straight gauge, the cost can be quite different but that is most prevalent when you go to the aero shapes and really high end tubing types and the cost of tubing is a relatively small percentage of the overall "cost" of the frame, time is the big $$$.

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                          • #14
                            Gary350,

                            Thanks for the eye candy. Very, very nice work.

                            Brian
                            OPEN EYES, OPEN EARS, OPEN MIND

                            THINK HARDER

                            BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

                            MY NAME IS BRIAN AND I AM A TOOLOHOLIC

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                            • #15
                              Check this site for ideas -

                              AtomicZombie.com is a cool site for bicycle building on a budget. Check it out.

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