Episode: 2962
Title: HPR2962: Bespoke bike building
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr2962/hpr2962.mp3
Transcribed: 2025-10-24 13:56:47

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This is HPR2962 for Tuesday, 10th December 2019.
Today's show is entitled Bespoke Bike Building,
and it's the 10th anniversary episode show of Brian and Ohio.
It's about 25 minutes long and carries a clean flag.
The summary is, Brian and Ohio continues his Bike Building project.
This episode of HPR is brought to you by archive.org.
Support universal access to all knowledge by heading over to archive.org forward slash donate.
Hello, Hacker Pope of Radio, Brian and Ohio here out from under my rock.
Part 3 of the long wheelbase recumbent bike build.
Before I start, I wanted to say thanks to Ken and Huka for giving up their time on Floss Weekly
and talking about HPR as a project.
Hopefully we'll see maybe Randall Schwartz produce some shows that be kind of cool.
He's an interesting guy.
Anyway, this is part 3 of the long wheelbase recumbent bike build.
I'm using the plans that are available on the site recycled recumbents.
There'll be links for all this stuff in the show notes as well as pictures of what I've done so far.
And of course, there's also thanks to John Culp on HPR-1282 for his building this bike ahead of me.
And so this is my version of it and where I'm at right now is when last left to you,
I had taken two perfectly serviceable bikes and I had cut them up into pieces.
And that's where I'm at right now.
So now the next step in the process is to start putting some of this stuff together.
And before I go into the, I recorded my work.
And before I go into that, I want to give a couple bits of explanation.
First off, brazing is what I'm using to braze the bike with is a copper brazing stick.
And I refer to them as sticks in the most recording.
Copper brazing sticks that are of a flux, a powdered flux on the outside of it.
They're like the length of maybe 12 or 15 inches long and about an eighth of an inch thick.
And that's what I'm using as the brazing metal.
The torch I'm using is a Benzomatic.
It's a very inexpensive, like $25 US dollars for this thing.
And two gas torch that I'm using, compressed oxygen bottles and map gas to do the brazing.
And the where I'm at in the building of the bike is on, basically I'm going to step on the recycled recumbent website on page on the page that says Mach 1 drawings.
The completed page 1 and I'm in page 2 and I'm starting it to page 3, easy clone, first assembly and second assembly brazing.
And so what you're going to hear now is a description very, very much stream of consciousness as it's happening as I braze together and assembly 1 and assembly 2 of the bike.
One thing I didn't really discuss in the recording is how I made the first part.
There's some special cuts they're called fish mouths and I've found some really good instructions on how to cut these just using just regular hacks out of the most special tubes on a site called recumbence.com.
And I'll put the link in the show. It says whistle recumbence.
They have a lot about racing recumbent bicycles, including the human human parts speed challenge that happens every year in Nevada.
And it's got a lot about building techniques and building bikes and basically all kinds of good information.
And there is a page that at the very bottom talks about how to cut fish mouths in tubes to using just a hacksaw and straight cuts.
And so I used that to get the one fish mouth that had to cut into the first assembly to get the pieces done.
As far as the pictures go that are going to be in the show notes.
Picture 1 is kind of just a mocking up of the parts just to see how everything's going to look.
Pictures 2 through 5 are the actual putting together of assembly 1 prior to, prior to brazing it up.
And then picture 6 is a pre brazing shot.
And then the last picture is it's all put together as far as that first group.
And then the second group of pictures, what you'll see there is the jig I used, which is kind of a spin off of what John Culp was using my workbench and some aluminum angle pieces to hold the pieces straight in plain so that the bike will end up straight and ride decently, hopefully at the end here.
And picture 11 will be the final, what it looks like after it's all brazed together.
So if there's any questions or comments just leave them in the show or leave them in the comment section or if you get inspired by this talk about something you've built recorded and put it up on HPR.
Now without further ado, let's join our intrepid hero as he attempts to put these pieces together and build a bike.
The mask, some gloves, lighter, the sticks.
All right, I'm going to join this on a few of that.
Whoa, my goodness, that was a little bit much.
Ah, that better.
That's all flame.
I send my bras.
Good map gas.
So map an oxy.
Get the oxy to turn on.
Son who used this torch set of pretty tricky.
And I tried to earlier, it definitely is touchy.
Here comes oxygen.
Let me try that.
No expert on this.
Bring myself the house down.
I can't see a dark thing.
I'm just heating up the tube.
From what I've seen, this is like soldering in a lot of ways.
So you're going to get the metal warm enough to melt the brazing rod and not use the flame to do it.
So it's pretty good and pretty orange already.
Just good.
I think what I'll try to do is
it's definitely taken some now.
That's the sputtering that I heard right about.
It's melting pretty good now.
I have to do this in two sections.
I want to flip it over.
I'm feeding it in there.
It's just going in.
Oh yeah.
Digging this.
I'm going to drip it off.
I'm going to shut off here.
I used about half a stick or so.
I'm going to turn off the oxygen first.
I'm going to turn the map off.
Okay, they're both off.
Oh yeah.
So I ended up with a half of the tube.
I should have taken a picture to begin with.
Sorry about that, but I think you're sure there'll be enough pictures that come along here.
Oh yeah.
Here's the first.
It's not pretty.
It's definitely like soldering.
You get it real hot and just tube just feeds right in there.
I'm going to have to flip it over and do the other side.
I'm sure there'll be some grinding.
That was that blob on the one that was definitely where I started.
But once you got it hot enough, it just flows right in there.
Something I've never done before, and I've always read and thought about it, but it's definitely...
It's just like soldering, except on a larger scale, like soldering an item on a circuit board.
You use your iron to get the thing hot, and then you feed the solder in.
And it just, once it's warm enough and you got the right amount of flux, it just flows right in.
You can feel it flowing in.
I'm going to shut off the recording now, and I'll give you an update when I'm done with this first part of the brazing operation.
Okay, so I'm starting on Assembly 2 here.
And the first thing I have to do, and I've got a picture of it in the show notes, is there's a little leftover break cable fitting that was on the original bike wall.
And I've got to cut that off because I'm going to... you have to sleeve...
You have to sleeve bike number two's back end into the top two.
This sleeve pretty nice, as long as this nubs out of the way.
And then I've got a jig to align the frames.
Kind of an idea I saw from John Pupp's pictures of his building.
I've got a variation on that, but...
And then...
I've got to strip off some of this paint, so that I can braze it.
Now that they're brazing isn't quite as mysterious processed for me anymore.
The brazing worked pretty well, actually.
So the first time I've ever done it, I'll be able to move on from there.
So that's off now to cut some pieces to size, the tubes, and then I'll strip off the paint.
I'll talk to you when I get back on with that.
All right, I got the paint stripped off, and I've got the frame jigged up.
I took some aluminum angle that I had, angled aluminum, and I stuck it in the jaws of the workmate,
which has really been super helpful tool for this project.
And that's aligned, made it really easy to align the down to from the second donor bike that's going to...
That part all has to be lined up in a plane in order for the bike to have to make it ride straight.
So this is the first kind of critical alignment.
And I used a picture that John Colpetti had a bigger piece of free metal that they used to dig it up,
and I had these smaller pieces of aluminum in this workmate, and it worked out pretty sweet.
I'm happy to... now that brazing isn't quite so terrifying to me.
I'm attempt to braze around this last piece, and then I'm not going to be able to work on this project for a few days after this.
So I wanted to get this done, give me a good start about what I think is about probably the halfway point of building the frame.
I will record some of this brazing, if I don't burn my eyebrows off or anything,
and when I get done, I'll edit that, you know, just clean it up, and then I'll give a little report on how I think it went.
All right, now I got the plane going.
These are benzo-benzo-matics or whatever they are, that are very...
Man, they are just unbelievable.
Well, I'll try this again here.
Why is this a type of...
The little knobs they give you to adjust the stuff are very...very...
finicky.
They just start lowly to go from nothing to almost everything, and you know, that's what you get when you buy.
I don't know, I'm actually not that much for the whole thing.
All right, now I got the oxygen that, once you're starting to add oxygen to the map gas,
and you really get the nice clean flame.
Yeah, I think I got it.
It's a pretty good flame now, you know.
Start heating the tube up, and I probably have to do this in two spots again.
It takes too long to get the tubes of orange flow, and then what...
Once you get a good temperature and get the brazing rod,
which has got this flux on it, once it starts flowing, it really gets nice,
but it's getting it going.
It's kind of, you know, probably take years for doing this to get good,
and I'm not really going to do it in this project, and it feels good as it's going to be.
I didn't cut these tubes down very much because I realized that
where the forces are acting, that having those tubes long inside,
although they won't be brazed all the way through,
that would definitely help with the strength of where the forces are on the blight.
You know, just kind of thinking about how, when you're sitting on it where the weight is,
having these long will definitely help with the whole...
keeping the... keeping the strength of the tube in.
All right, there it goes.
Not too good.
Not too good.
Not too good.
It's got the pop in there, yeah.
I'm going to kind of fix that down, if you...
I think it's going to go in.
That's keeping it over, but I think it's going to flip it over.
It'll be, it'll hold it.
It's off in the plane, like what I got there.
Let's see what's going right into that joint.
I think that's a brazing rod that I got might be a little bit too thick.
Switch to the other side here.
I'm going to do this.
Pulling everything up.
I am working on my garage in a ventilated area.
Yeah, I protect them on.
It's a bit too thick.
Oh, yeah.
Oh, I'm going in there.
Yeah.
They not edit this.
I've listened to stuff on HPR, guys swimming on rivers and people playing instruments and all kinds of stuff.
And maybe people will be interested in this.
It's a cool process.
I highly recommend trying this out.
It's not as difficult as you might be able to believe in.
It doesn't take too much equipment either.
It's kind of cool, you know.
It's going in two pieces of metal.
I will say my son does a hobby by smithing and he makes knives and stuff.
And I've watched him and given me kind of the emphasis.
It's right.
He's so good around molten metals and things.
You know, it's probably not enough to follow him on a project for extra sometime.
I think I'm going to call that good.
Yeah, I think so.
Turn off the oxygen first.
Oops, turn off the gas.
And there you go.
I think I'm going to call that good.
Yeah, since so.
Turn off the oxygen first.
Oops, turn off the gas.
And there you go.
That's, take a look at it.
Take my glasses off here.
Yep, I think that's good.
I think it's smoking out the end.
I'll take a picture of it here and put that in the show notes.
And I think that I'll call assembly to put together.
Next part will be bending the rear triangle where the back wheel is going to be.
And that will get attached brazed on right here where my finger is pointing on this one picture.
And then there's some, some long pieces parallel to that top bar that are welded in while the brazed in.
So good progress this weekend.
I'm pretty excited and hope, hope you've enjoyed following along with this and hope I've inspired you.
Build a bike or do something else of metal.
And it's bright in the house.
Signing out.
Good night.
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