stryped

This idea started with my frustration of finding a reasonablly priced road bike to use in the ocassional triathelon. I am a runner who has wanted to try a triathelon. (sprint distance to half ironman).

I work on cars and have a 30x30 shop with a mig welder, oxyacetylene set, grinders, chop saw, etc.

Is this feasable and is it possibile to build a decent bike at home on your first time? Is it better to use chrome moly, aluminum, or ???

Can a person use a lug set with aluminum tubing?

I appreciate any advice.

Scooper

Aluminum tubing has to be TIG welded. Some early aluminum bikes, notably ALAN and Raleigh Technium used lugs, but the tubes were glued rather than brazed into the lugs and that proved to be less than optimal in terms of longevity.

You might want to download the scanned pages of Designing and Building Your Own Frameset by Richard Talbot, P.E., from Bob Hovey's website HERE to gain some appreciation of what's involved in building a silver brazed lugged steel frameset.

Another source of good framebuilding information is The Paterek Manual.

Eric Estlund 

There are a lot of great reasons to pick up frame building, but I can almost guarantee that you'll be able to find a good and inexpensive bike suitable for sprints for less then you are likely to invest. That isn't to dissuade you from frame building, but trying to get a cheap and racable bike in the first crack is usually an eye opening experience.

Six jours

I generally counsel folks that they should consider their first frame practice. I'm sure it's possible for a first frame to be useable, especially if made by someone with prior metalworking experience, but on average, I'd bet that most first frames end up hanging on a peg.

I also expect you'd find that by the time you've assembled all the tooling and materials necessary to have a good shot at building a useful frame on the first try, you've spent enough money that you could have just bought one in the first place. Getting into framebuilding to save money - unless you are looking to replicate extremely rare and/or expensive frames - is probably foolish.

unterhausen

you can't save money by building your own frame. Best to buy used.

stryped

Not all of it is about money but I like wworking on this kind of things. Cant aluminum be mig welded with an argon shielding gas? It can also be brazed/soldered?

I also wanted to make my 11 year old girl a bike for kids triathelons. She has her kids bike she has outgrown. Maybe taking the guts off that and putting it on a "kids" road bike frame, making it a single speed for her.

fietsbob

I'd suggest Steel as a 1st attempt bike frame material
tweaking/cold setting, out of line aluminum joints, is not a good idea..

.. retail on all the components, new,
will have you looking for a used bike , anyhow, to strip their parts from.

stryped

What kind of steel? What about crome moly?

Is it possible to make a light bike out of steel?

Scooper

Yes; for your first frame, you shouldn't try to go with the lightest (thinnest) tubing. My first frame was made with a Nova double-butted OS chromoly tubeset for ~$100. It's a 61cm frame and weighs 4 pounds.

GrayJay

Scooper- note that your link was actually to a Dedaccia SAT 14.5 tubeset, this is a heat treated and very thinwall tubeset that would be less than ideal for a first time builder. A slightly thicker non-HT tubeset (such as what you likely did use) is adviseable for a first time builder. Link should be;
https://www.cycle-frames.com/bicycle-...-BB-shell.html

Another good source for obtaining appropriate 4130 CrMo tubes is;
https://www.bikelugs.com/store/

Scooper

Right you are; thanks for the correction.

stryped

How hard is it to solder these thin tubes? I have used electrical solder and welded bu that is it

fietsbob

Still ride the Columbus Aelle tube set frame I built in 75, occasionally..
More of a Light touring geometry and fittings..

silver solder. and cast lugs , are the combo..

the fit is best thin to draw in silver solder
to take advantage of lower melting point

then you heat the lug more than the tube ..

GrayJay

Surface prep, correct flux and brazing rod are important to do a good job. Not much more different from OA welding in terms of two handed hand-eye coordination. Choice to make as to if you will use silver rod (flows easily into lugs, works at lower temp but the actual silver rod is expensive) or to use bronze rod which with which you are more likely to overheat the tube. Excelent source of great products for either is;
https://www.cycledesignusa.com/

Before you take a torch to your frame tubes & lugs, get some strait gauge 1' and 1-1/8" tubing with 1/16" walls so that you can make a bunch or rings that slip over eachother and practice your technique, get a feel for the heat requred and do some destructive testing to confirm good penetration of the braze metal throughout the joint.

squirtdad

look at the stickies, How to build and lugged frame and how to build a Mixte to get feel for what is involved. I haven't built a frame, despsite wistfully looking at these threads, but remember the frame is only part of the cost....your still have to get all the componenets...... I have rebuilt enough bikes to know you have to be really careful to keeps the costs down. Based on just rebuilding a frame with new/new user parts. Don't do this with the idea you will save money.

Scooper

^^
Agreed; building your own frame is not the way to save money. What it does do is give you the pride and satisfaction of riding a bicycle you designed and built for yourself. The first several frames will almost certainly be flawed in some (probably minor) ways, but your skills will improve with practice.

stryped

Would black iron pipe be ok to try a bike? I would like to make something for my 11 year old daughter who has hit a growth spirt and outgrown here current bike.

mudboy

Actually, I built my first frame because I was looking at custom (Bilenky) and what I wanted would have run me well over two grand. What I built ended up costing me a little more than half that with paint, materials, and shop time, fits me like a glove, and is really just what I wanted.

mudboy

No. Just no. Nova usually has some sort of special running that will get you tubes, lugs, and shell (no fork fixings) for around $100.

stryped

Where is a good cheap place to buy the other parts? (wheels, gears, pedal).

if you use a pre made lug, do you still have to make threads with a tap where the pedal cranks go?

Thanks.

ClemY

I built a few frames for myself in the late ‘70s and early ‘80s because I couldn’t afford what I wanted to ride and I had some pretty specific ideas in what I wanted. My first bike was a criterium frame made with Columbus SP tubing. It was intended to be a very stiff frame for a big guy like me who is a roadman sprinter. It worked very well for that. Next I made tandem so I could ride with my 5 yr. old daughter, followed by a triple so I could ride with both kids. Those kids are now in their 30’s and those bikes haven’t seen the light of day in years. I also built a commuting bike with 26” wheels to absorb the bumps of frost heaves and broken pavement on the way to work, and a folding bike, that doesn’t fold, but comes apart and can be transported in a car or plane. Lots of fun, but I probably didn’t save much if any money.

stryped

Why not use mild steel for a road bike instead of 4130? I know 4130 is stronger, but doesnt it weigh more?

Scooper

All steels have pretty much the same density, but because 4130 is stronger, the tubing can be drawn thinner. Most AISI 4130 bicycle tubing is butted or double butted, meaning thicker on the ends where the tubes are welded or brazed, and thinner in the middle. Thinner is lighter, so thinner walled butted 4130 is significantly lighter than mild steel, typically straight gauge (not butted) AISI 1020 or 1030 carbon steel.

clasher

You can just buy straight-gauge chromoly from aircraft spruce (or any other metal retailer) and use brass to learn how to braze. It'll save you money instead of throwing away a frame or two for learning purposes. A used bike can be had for the cost of tubes, gas and brass depending on the local markets.