bmx bike frame

[TIGcheez]

hi me and my dad are trying to make a bike frame for a huge bike. we want the seat to be about 7 feet in the air.and we are not sure what kind of metal to use. i dont want this thing weighting a 100 pounds.

thanks for any ideas.

[MAC702]

Knowing what machines you have for fabrication would help, as would knowing your welding experience, though your post indicates it is not enough to select your own metal.

How strong does it need to be? You can get by with steel, easiest to weld, in some pretty thin (read: lightweight) tubing sometimes and get the strength you need.

Aluminum will also be a popular choice, but requires greater skill in welding, and usually more expensive machines.

Then there's titanium, and the really exotic stuff.

How about balsa wood and Elmer's? And in my best Norm Abrams' voice, "and just a few brads to hold it together while the glue dries..."

[TIGcheez]

I am not sure of the machines name but i have alot i can work with. i go to a school for three hours ever day they got tons of fun stuff and i should have my AWS in about a year. i have been welding as a hobby for about a year but been getting in to trying to get my AWS for like a month your two.

but anyway.

i need it to be as light as possable, alumminum wont work, im not to good at that yet but this is the second major project i will be doing.


this bike needs to be able to suport me (185 pounds) thats the main issue

thanks

[BCarlucci]

On any bike alum or an exotic metal is the way to go, otherwise i'd go with some thing walled tubing and hit up that route, without being able to use Alum your bike is going to be heavy. I know i've repaired my friends bikes that we're alum, and also for a customer of mine that is a bike shop.

Good luck,
BC

[prsc]

A good metal to use would be 4130 cromoly, thats what most bmx bikes are made out of, it's tought and light, just use thin walled tubing, and tig weld it with ER70S-6 filler wire

[Bmxin^Bjorn]

as you can tell by my name i am a bmxer and what you dicribe to make isent a bmx but PRSC knows what he's takin about. I would jus use thin walled steel from the local steel distributer. I have used thin walled steel for my last race bmx and it worked perfect and it weighed .. i think it was like 6 LBS or somthing .. it was relly light. I jus mig welded it with a mm135 the dopest little welder around!