Alt Bike Culture - Building a Tallbike info

I start my welding class next week, and the long term goal of that class if to build a tallbike. I've done alot of searching (maybe not hard enough) but i'm looking for info on someone whos done a DIY (or something of the sort) on constructing a tallbike. Have questions on the best ways to align the frames, how do the headsets work, those sorts of things. Any help, direction, or flaming is appreciated, because i'm sure i'll get some of that as well.

sherfy

There's a thread titled "Tall Bike Step". Read that and get back to us with any questions.

I read through the article Tall Bike step, and actually picked up a few frames yesterday for free that might work for what I need, but have some questions on technical stuff.

Whats the best form of joining the two bikes, I've heard of people doing things other then welding?

Do the head tube diameters have to be the same?

I really dont have alot to go on here, and kinda just blind firing, so if you're lining up the frames and ensuring the angles are correct on both head tubes, then do you just weld the bottom brack shell, to whereever the BBS hits the tt?

I've also seen people using two forks, and welding a piece of pipe, inbetween the bottom of the top fork, down the the top of the bottom fork, is this the most common method?

any help is appreciated, or any sources

Making metal stick together:
Welding is definitely the best. Bolt together is more complicated and less sturdy. Tape is not recommended, but please post pics if you choose this method. Bolt-rat builds hold a special place in my heart though. They can be quite classy, and by classy I mean less classy than booger welds. And less classy is a state which we are all trying to achieve.


Headtoobs:
not really, they can be diff (mine is) but it's nice, then you only have to have one complete headset...

Framebuildersalignmentjig:
A good method. You need a broomstick, 2 boards, 2 bungie cords, and a 40oz.
Open the 40oz. Imbibe.
Lay both frames in approximate position on flat surface near welder.
Shove broomstick in both headtubes.
Lay one board underneath and one over the frames so that they cross both the toptube and downtube of both frames.
Wrap TIGHTLY both ends of the boards to sandwich the frames together.
Make sure everything lines up. (yes about the BB, wherever it lands on the top tube)
Tack weld the mutha.

I may have forgotten *****, I'm drinking a 40oz.

For the fork:
find some pipe to use as an extension. Cut your steerer tube in half. put the extension in and make sure it is the EXACT right length. You're probably using a threadless system which means it needs to be within .25" or so. Once it is the right length weld it good, and then grind down the welds so that it fits in the headtubes.

All that's left is tossing in a brace between the downtube of the top frame and the top tube of the bottom frame. There are many ways, it doesn't really matter, use whatever turns you on.

Now put the bike back together. Your chainline is probably ****ed, fix that somehow and you will be the badest mofo in kindergarten!

Here is a pic of me riding my first tallbike down in Memphis right before I took off for bicycle heaven Japan. I started out like most alt bike builders by chopping up and using old bike parts. But as you progress in skill you will find that using raw steel tubes is much more fun. You can paint when you are finished but your designs will have more range. For example, instead of worrying about how to line up two head tubes, just make a 4ft head tube. But when I started I made a set of handle bars out of an old chair on the ground because that was available.

Here's a little write up I did when I built my tallbike. The way I did it may or may not work for you but I've had my bike for a year and it's held up fairly well considering the abuse it has endured. I made some changes this week, I'll add some new pictures soon.

http://kemmer.fotopic.net/

We just had a neighborhood build day, it was awesome, got 4 tallbikes near completion! You can see a few photos here:

http://www.flickr.com/photos/alwayseverywhere/

The host made an awesome little zine guide for tallbike construction, I'll see if I remember to scan it and post it...

http://farm1.static.flickr.com/208/507819154_72fad70fb9.jpg

I'd be interested in seeing that, please post it when you get a chance.

okeedokee, here is the workshop "write-up", mostly just pics and scans:

http://gabrielamadeus.blogspot.com/2007/05/freakbike-workshop-520.html

i know this threads been out for a wile. but i gotta know alot of ****. i have an arc welder. i dont really know how to weld. i have bike frames. i want a tall bike. now is this a stupid thing do to first or should i try somethin else? any advice would help thanks.

All that's left is tossing in a brace between the downtube of the top frame and the top tube of the bottom frame. There are many ways, it doesn't really matter, use whatever turns you on.


I have this on my tallbike, and while I don't question that it is adding support I also decided to add some backbracing to keep the flex on my chainstays down and add rigidity.

http://img.photobucket.com/albums/v419/wethepeople101/100_1135.jpg

I also decided to install the back brake delete kit, which enables the bike to eat your foot causing you to fall gracefully (or not so gracefully depending on how many times you've done it) over onto your side.

http://img.photobucket.com/albums/v419/wethepeople101/100_1136.jpg

http://farm3.static.flickr.com/2284/2126136648_ee09f2d7bb.jpg?v=0

I'm interested in building a tall bike so I appreciate the info posted. My one question would be about the welder. Do you need a proper full size welder or could you get away with using a portable handheld type?

Bicycle tubing isn't that thick, so most welders can do it. That said, I've run across welders that can't weld sheet metal.

The weld for the seat tube and fork were done with a tig welder. However my head tube extension that I welded in was done with a portable welder.

Do you think in your opinion the a portable welder would make strong enough welds for the seat and fork?

If prepared properly I would feel confident using a portable welder, just ensure that you have proper penetration.