Road Fan

How old do you want to go? Bicycles have been made of steel tubing since about 1880, if not earlier.

unterhausen

I always liked the photos from the Merckx factory when they were building frames. Pre-heating one frame while they were brazing another on a carousel

Early Treks were made by brazing the head tube/dt/tt and then in the next operation brazing the seat tube and bb to that assembly. Then later the stays were attached. There are some pictures of the factory that Dale Brown posted.

oj.

Wow, this got much more traction than I was hoping for. I'm sorry for being so naïve about the processes involved in making a bike.

To address the point of carbon fibre: I am not writing that section of the report. The other members of my group who are not as interested in bicycles as I am are doing so, and so will almost certainly go for the low hanging fruit in terms of research. I imagine this would land them on one piece laminated carbon frames, but I'll make sure to verify this.
Since it may have been unclear what my focus was, it is a specific section of the bicycle manufacture industry that is not the modern carbon fibre bicycle. If this wasn't unnecessarily made into group work, I would have just chosen one that I liked. However since it's group work I wanted to see what was out there that would contrast nicely with what my teammate is writing about. I'll probably be writing about hand built (small/single run production) steel frame bicycle using lugs and brazing. This seems to be very well documented.

I'd also like to add that this is a 2nd year report, and it is only a three week project. My lecturer doesn't seem all that interested in the nuance of the process, he seems only to care about info being there in a good presentation. I'd love to do this report justice, there's easily enough information out there to write a couple books on the subject, but I don't currently have time. This is all online delivered, and I'm having a tough time as it is making sure I'm not putting effort into work of low importance (in terms of my grades). However, I don't want to make it seem like the efforts of those who have responded are in vain. For much longer than this report has existed I have been keen to build my own bike frame from scratch. All of the processes shown here can only make that prospect happen sooner. I used to think bamboo frames were cool, but who's to say that I won't be making my own lugged carbon frame.

Thanks again for all the responses, once again I'm impressed with the forthcoming nature of the forum.

I've written these places down. At the moment due to total lockdown across the UK I won't be able visit, but maybe in my long summer holiday when restrictions are relaxed.

guy153

I found this video of the Atlas factory in India very interesting:


I think it may have sadly closed down but only just last year because Covid.

Anyway I wouldn't be surprised if a lot of the equipment there actually _was_ the Raleigh factory, or some other one, exported to India in the 50s or 60s where they have been using it practically ever since.

Lugged construction with hearth brazing. Also notable is that they make almost everything on site from raw materials. They didn't just make the frame and get the other bits from Shimano like now.

You see this on old bikes from the period. A lot of the parts are stamped "Sun" or whatever the brand was.

Doug Fattic 

oj, a wise student always tries to figure out what the teacher is looking for in a report or on a test. I doubt he cares about the differences of sliver compared to bronze brazing or the ride qualities of steel vs aluminum vs titanium. This is just a guess (but probably a decent one since I was a high school social studies teacher before I began building frames), I would think he/she is looking for reasons bikes were built with certain materials using certain methods during a certain time period and then what where the factors that brought about a change? Those factors would include technology as well as marketing forces. Keep in mind that companies are always looking for ways to increase their profits. And those factors have a strong influence on what materials and joining methods are chosen.

The Cliff notes version is that steel had both the properties and ability to be put together into a frame right from the start of the modern bicycle. In the UK, Reynolds figured out ways to make tubing better for bicycle frames. The Haden company made lugs. Hearth brazing (a huge natural gas flame augmented by air from a squirrel cage) supplied the heat to melt the brass to hold everything together. Before that the frame was laid on a bed of coals. In the 30's (i'm not sure exactly when) oxyacetylene equipment became a more effective heat source. Sometime in the 70's/80's TIG (Tungsten Inert Gas) welding became a method for joining not only steel but also aluminum and titanium without the need for lugs. This made manufacturing faster and cheaper. Aluminum in particular was popular not only for manufacturing savings but also because it sounds lighter. Carbon fiber frames began in the early 80's (i'm going from memory so this needs to be fact checked) in an attempt to provide the lightest possible frame material. Its biggest advantage is not just its light weight but also can be suitable for heavy guys (steel frames can be made really light but will break under a heavy guy). The problem is that carbon is harder to make into an individual custom design (while easy to do with steel).

The best heat treated thin-walled steel tubing (that has the best ride qualities) does not lend itself to production building methods. That is why it is only used by skilled custom builders. Unfortunaely small builders don't have much marketing muscle so that limits its acceptance as a material of choice.

BTW, Craig Calfee makes a DIY custom bamboo frame kit. That sounds like something you might want to consider. His business of making carbon and bamboo frames is located in California.

oj.

I made sure this was clear, he definitely only wants the 'process' and not the 'why'. On an engineering degree this sounds pretty ridiculous, but anything that wasn't how the process was performed he was calling 'design'. I had to grit my teeth here, I loved writing the 'why' when I did this kind of report in high school, but this guy just wants steps (he was getting noticeably exasperated at the prospect of why). This whole module is a shambles anyway, the man running it is incredibly overworked and he makes things group work just so that he has less marking to do. I'm making the most of it, but like I indicated before this isn't my main focus of the semester.

I think I looked at this before, but was turned off by the cost of shipping it to the UK. I'm more into on building solutions rather than novelties now, so bamboo will be shelved. Unless, maybe a bamboo trailer becomes necessary...

Doug Fattic 

Well in reality that makes it easier for you. Take for example my 7 steps in post #10 and elaborate with more detail on each one to bring your report up to a high standard (or at a minimum enough to impress your teacher) with the assistance of resources from other posts on this thread. Of course while your teacher may not be the best, he assigned you a topic you like and with the help of the forum (and other contacts you will make), you can learn a lot for your own personal growth and understanding. Having to write on this provides you with an excuse to contact various knowledgable people that will prepare you for any journey you may choose in making (or at least understanding how to make) bicycles.

cbrstar

Early bicycles were made from gas pipe, but a big innovation was in 1911 where a man named John Moon invented a process for seamless tubing. It was perfect for bicycles because the tubes were thinner, stronger, and much lighter. There was quite a cottage industry of frame builders out there making bikes from old gas pipes. And I believe that is also why many frames were brazed with lugs and not welded.

Mike_Kelly

Here is something I found on the net that is mostly text.
https://www.instructables.com/Build-a-Bicycle-Frame/
There is also the Proteus Frame building book if you can find one.

guy153

​​​​​Gas pipes made of mild steel are easier to weld than thinner wall seamless tubes though.

Before TIG became widespread in the 1970s it was pretty hard to weld either. And then the high strength alloys like Reynolds 531 were weakened by the heat of welding so you had to braze them whether you liked it or not.

Then at some point we started using CrMo (and newer Reynolds formulations like CrMnMo) that were suitable for welding.

Low-end frames are still made of rolled up mild steel around 1mm or more thick and this is often robot MIG welded. This is probably the lowest cost process now.

The thing about brazing is the filler metal is actually quite pricey and this is going to add up on low cost mass produced frames.

Bimmer69

There’s a good framework (pardon the pun) here

How bicycle is made - material, manufacture, history, used, components, dimensions, machine, History

although it pertains to more modern manufacturing methods the steps and objectives are the same.

ramzilla

Steel bike Gnomes....................................

C9H13N 

They were forged in secret, in the land of Mordor, in the fires of Mount Doom.

That’s why we are drawn to them and we can’t let them go.

homelessjoe

In japan the bicycle industry started with the gun makers because they knew how to manufacture gun barrels and used that tech to make bicycle tubes.......as many small shops sprang up all over England and Europe the makers would buy tubes and lugs from a number of tube makers and every shop would hand file the lugs into fancy designs to make their frames stand out and be identifiable......brought to a fine are in England.....check the lugs on Ephgrave......Hetchins.....Carlton gem

Darth Lefty 

Japanese industry also invented what is now called 7075 aluminum alloy and it was a wartime secret. The USA got the formula from wreckage of a Zero

shylow1948

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Hello , i have a 1915 ? bike with the frame being soldered together and a 1880 Tricycle that they used hot rivets that hold the frame together,

jet sanchEz

Has this one been posted yet?

Richard Sachs

https://vimeo.com/69886859

MEC

You might look at Peter Mooney in Belmont Massachusetts.