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Building your own bike frames - anyone here ever done it?

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  • #16
    I'll throw in some thoughts here too as I've mulled over building my own frame(s) too.

    Talbots manual is available as a PDF in several places as is the Paterak manual of frame building, both worth a look.

    One of the big dis-incentives for me has been the need for a jig. The quality of the frame will obviously be reflected in the quality and rigidity of the jig. A lot of time and materials could be invested in a jig and I'm not sure that I'd be interested in building more than one or two frames and one or two frames I feel will not amortise the investment in a good jig.

    For joining steel tubes I'd go with silicon bronze fillets using a tig welder as a heat source as I feel this can give very strong joints with minimal heat change to the steel tubes.

    There are tube sets available that are specifically designed for tig welding (not brazing) "Optima" was an early Reynolds tube, I don't know whats out there now.

    I hope I don't sound too negative, for me overcoming the jigging issue is the big hurdle but I could be overthinking this.

    All the best if you do give it a go.


    Alan
    West Sussex UK

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    • #17
      Alan, if you have very good miters, a relatively flat surface, and a full size drawing, you can build a frame with little to no jigging with basic tools. A bicycle work stand helps, but isn't a deal killer. If you are doing lugged construction, so much the easier. It won't be fast, but its very doable.

      The jig is not a form to keep the frame straight. A well made frame should have very little distortion... and that is the high art of it. Its no trick to weld a frame and then bend it back to straight. A badly constructed frame will immediately distort when taken out of it's jigging, no matter how robust. Many jigs hold the tubes very lightly, or not at all (relying on the miters). The builder then tacks the frame together, and welds out of the jig.. often checking on a surface table throughout to check for misalignment... certain weld sequences can then bring it back around. This is the stuff that takes a lot of time behind the torch to master.

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      • #18
        I'm currently working with a local frame builder. She designs and builds them to fit the customer and also does customer specific artwork for the bi-lams and other bits. She started out with just a hacksaw and files, I'm helping her get into the machinery side of it. She now has a Grizzly retrofit CNC mill with 4th axis. She is very smart and has learned the Cad and Cam on her own. You can see her work at www.pedalinobicycles.com. Also an Instagram site with lots of details. She builds road bikes, fat bikes, gravel bikes, etc., whatever kind is wanted.
        Kansas City area

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        • #19
          "I wouldn't get too excited about what an engineer says about this. Has he/she built a frame? I assume you will be building a traditional double diamond frame. It will be built in your garage or the like. You will likely be using either bicycle specific tubing, or other high quality tube, like 4130, etc. The engineering has been done by the tube manufacturers. The double diamond frame has been well settled now for 100+ yrs. This is not a slight to anyone on this forum."


          Yes I'm sticking to the standard double diamond tube and it will be a 29+ (i.e. 3" wide x 29" dia tires) hardtail that will eventually get a front suspension fork (although I may run a rigid up front for a while too, like I am now on my current bike). And although it will be a standard diamond, I will be incorporating some special features I want. Like a slightly dropped top tube to get more standover/groin clearance. Also fat, curved chainstays and updated standards like tapered headtube (to accommodate the newer suspension forks), wider rear wheel spacing (to accommodate the newer/wider 148mm Boost Hubs and rear through tube axles) and disc brakes (of course).

          The bike will be a dedicated single speed (SS), probably with an Eccentric Bottom Bracket (EBB) for chain tensioning. So many bikes I have had in the past have had flexy chainstays for how I ride. I weigh around 200lbs and ride singlespeed exclusively and have for many years now, so my legs are developed, sinewy and powerful. And on singlespeeds you have to really stand up and mash on the pedals full force to get up hills etc. That's why I've had trouble with off-the-shelf bikes standing up to that kind of day in/day out use also combined with endless hammering over tree roots where I ride which has broken the last 4 store bought frames I've had.

          As to taking "pro" engineer input, I'd love to hear what they have to say. But honestly? After riding store bought bikes from high end manufacturers like Trek, Santa Cruz, Bianchi, GT (when they were still an American company) and Gary Fisher (before being bought by Trek) all I can say is that I'm not terribly impressed with what they've come up with over the years. It seems the marketing department has more to say about what they release then their engineers do. And from the perspective of an SS'er, the SS designs they've come up with are usually very lacklustre and poorly thought out. Probably because the engineers personally don't ride SS and are unaware of what is best and what is a stupid fad.

          SS is a subculture within the biking community and the engineers focus their efforts on what the most customers want. I get that, but you would think something as simple and old school as building a great SS bike could be nailed every time. Not so from my experience. As an example, currently I have a state of the art aluminum Trek "Stache" setup for SS. Trek's website brags it's "SS ready" with horizontal dropouts. And I really love the bike's handling, 29+wheels, frame geometry and relative lightness. But the goofy high-mounted chainstay they put on it (to achieve a rear wheel moved as far forward as possible) flexes more than any SS frame I've ever had. This makes the chain slip under the most aggressive uphill climbs.


          Steel is an obvious choice. relatively cheap, easy to deal with, no back purge needed (like for ti), easy to make a 'safe' bike, tig, lugged or fillet brazed. Many custom builders fillet braze mtn bikes btw. Biggest downfall is you have to put a finish on it. If you learn to tig, Ti is not difficult..purging is the biggest difference, I actually find it easier to lay a bead with Ti.


          If I do take the plunge and learn how to Tig weld, then I might go for a Ti frame if it's not much different in terms of welding other than backpurging. I'm definitely willing to pay the difference in price for the lighter and more compliant Ti materials.


          Forget chopping apart old frames. Regardless of joining method, cleanliness is paramount. no need to muck about with old paint, rust, etc etc. Raw tubes can had relatively cheaply. Easily cleaned, straight (ish), known composition, etc so you can focus on your welding issues, instead of having issues due to old crappy mystery tubes. Get a few feet, practice your miters on the mill, and start practicing your joining.


          Ok, I'll definitely keep that in mind. Sounds like good advice.


          "I'll throw in some thoughts here too as I've mulled over building my own frame(s) too. Talbots manual is available as a PDF in several places as is the Paterak manual of frame building, both worth a look."


          Ok, I'll try and find both online.


          "One of the big dis-incentives for me has been the need for a jig. The quality of the frame will obviously be reflected in the quality and rigidity of the jig. A lot of time and materials could be invested in a jig and I'm not sure that I'd be interested in building more than one or two frames and one or two frames I feel will not amortise the investment in a good jig."


          I understand what you're saying and I've thought about this same thing. But I don't really need a fancy, fully adjustable pro jigging system like I saw on the previously mentioned BCN video on youtube. I would think I would be able to make a decent jig pretty easily either out of wood and/or by fabbing up a simple tubular steel fixture cut and welded with my Mig welder to the size for my specific frame. And since I like the size and geometry of the bike I have right now, I would likely use it as the fixturing template for my own frame. I'd have to make a few minor changes for the EBB and for the beefier chainstays I want to use, but otherwise I would weld the holding fixture to hold the bike I now have.


          "For joining steel tubes I'd go with silicon bronze fillets using a tig welder as a heat source as I feel this can give very strong joints with minimal heat change to the steel tubes."


          Good to know, I'll keep that in mind. I also saw on the BCN video referenced earlier that they have ways of brazing the frame in certain areas and sequences that really minimizes distortion.


          "The jig is not a form to keep the frame straight. A well made frame should have very little distortion... and that is the high art of it. Its no trick to weld a frame and then bend it back to straight. A badly constructed frame will immediately distort when taken out of it's jigging, no matter how robust. Many jigs hold the tubes very lightly, or not at all (relying on the miters). The builder then tacks the frame together, and welds out of the jig.. often checking on a surface table throughout to check for misalignment... certain weld sequences can then bring it back around. This is the stuff that takes a lot of time behind the torch to master."


          Good to know and this seems to comport with what is seen on the BCN video.

          Comment


          • #20
            I am really enjoying this thread.. good practical advice and insight.

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            • #21
              Look into the Lincoln Tig 200 welder.
              It has a good feature to cost ratio.
              You can get cheaper Tig boxes but the are from Chinese vendors and you are at their mercy for parts and service.
              If you can O/A weld you can tig weld. Same torch and weld rod control motions required.

              Comment


              • #22
                Interesting from a build-this perspective.

                To keep up and not being into bikes I had to go google a couple of the terms.

                200lb mountain biker: someone you want on your side when things get testy at the bar.

                SS: Single speed; as in fixed chain over just two sprockets resulting in a single gear ratio.

                Bi-lams: an extra piece of metal applied over an already braised joint; sometimes cut into a fancy pattern.

                Chainstay: that bottom tube that runs from the drive sprocket tube to the rear axle; essentially the spacer that holds the pedal axle and the the rear wheel axle apart.

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                • #23
                  Yeah, some of the terms are a bit fraught. What most folks call a single speed.. one gear up front, one in the back, and able to freewheel is more accurately a fixed gear. And what is now almost universal referred to as a fixed gear (same as above but with no freewheeling) is technically a fixed wheel. Bi lam is a 50 cent term resurrected by the bespoke/artisinal bike crowd.. usually referring to a lug, gusset, mixed joining methods etc.

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                  • #24
                    I wanna show up to the bicycle rally with an all MIG welded frame,
                    just to piss everybody off. You guys sound like a Starbucks coffee
                    crowd, with realllllly long coffee orders, with all the coffee buzz lingo
                    that makes you sound like a doufus when you order.

                    -D
                    DZER

                    Comment


                    • #25
                      This was my first and only "large" frame I've built. It's all SCH40 pipe. About 10% TIG welded and 90% MIG welded. These are pictures after spraying it with primer:







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                      • #26
                        And the finished frame. My sand rail powered by a GSX750CC





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                        • #27
                          Originally posted by Doozer View Post
                          I wanna show up to the bicycle rally with an all MIG welded frame,
                          just to piss everybody off. You guys sound like a Starbucks coffee
                          crowd, with realllllly long coffee orders, with all the coffee buzz lingo
                          that makes you sound like a doufus when you order.

                          -D
                          Yeah, nothing is immune to the march of the artisinal effetes these days it seems.
                          If you mig up a frame, be sure to do all the milling on a drill press as well!

                          Comment


                          • #28
                            Originally posted by Doozer View Post
                            I wanna show up to the bicycle rally with an all MIG welded frame,
                            just to piss everybody off. You guys sound like a Starbucks coffee
                            crowd, with realllllly long coffee orders, with all the coffee buzz lingo
                            that makes you sound like a doufus when you order.

                            -D
                            According to my research, MIG is not the favorite for bike frames simply because it's harder to get small welds that you know are good. With MIG, the filler heats and melts before the base metal does. With MIG it's easy to make a good looking weld that is too cold with poor penetration and prone to cracking.

                            In expert hands, that's not an issue. In the hands of a novice it can result in spectacular crashes during an off road ride when a joint separates.

                            With OA, Brazing or TIG you can add appropriate heat without adding more filler.

                            Re: TIG welding... It's not that hard to do structurally valid welds on aluminum, steel or titanium. It IS hard to make them beautiful. You don't need a $5000 welder to do bike frames. There are several import TIG welders that a have a good set of features for under $1000 and that work really well. I use and recommend the AHP for hobbyists. Cheap, light and good feature set.


                            Dan
                            At the end of the project, there is a profound difference between spare parts and left over parts.

                            Location: SF East Bay.

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                            • #29
                              According to my research, I am a porn star, but I don't film it.

                              -Doozer
                              DZER

                              Comment


                              • #30
                                After reading the posts so far I think you have a lot of advise, most of it good, and a lot to consider. I will add that I think fillet brazing is the way for you to go. Quality frames have been built using this method for a long time. The first mountain bikes by Joe Breeze and Tom Ritchy/Gary Fisher/Charlie Kelly were fillet brazed. I had a custom mountain bike frame fillet brazed by Peter Weigle, (a well known and respected frame bullder in CT) back in about 1988 and rode it hard for 18 years. After about the third repaint he did on it he told me to stop riding it before I destroyed a classic. Over the years some moisture had gotten in and there was a pin hole in one chainstay, (which he brazed up), but afater 18 years of off road beating it was time to hang it up. However the fillet brazed joints never were a problem. Fillet brazing doesn't heat the tubes as much as TIG welding and allows any angle as opposed to lugs, and a nice smooth fillet is a thing of beauty too. Makes the frame look like it was molded as one piece. It is a skill like TIG to be learned though. Practice first. Carefully miter the tubes to a good fit before brazing too. They say making a fork is almost as much work as making the frame, and if you are going to add a suspension fork later you need to make the rigid fork to the same height to maintain the angles you want the bike to have for handling. Keep us up to date as you go along, sounds like a fun project.

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