Monday, January 14, 2008

Catty Scrap Tall Bike

Several weeks ago I was in Pennsylvania visiting my friends Sean and Nicolle again. This time I went down there with a great idea, which, like all of my other great ideas, was actually just a really bad idea backed up with a whole lot of zeal.

The idea was to rummage around in Sean's scrap metal yard for discarded bicycles and weld them together into one giant bicycle. Building a tall bike is a pretty straight-forward process if one has access to just a couple of suitable bike frames and knows how to weld. If one has access and endless supply of unsuitable bike frames and knows someone who has seen someone else weld, the process is significantly less straight forward.

We spent the first day piling up bikes that we found in the yard and discussing plans at the Allentown Brew Works, which was hosting their annual Brew Fest while I was in town. Keep in mind, inspiration comes faster when you're drunk and in Pennsylvania. I had found a couple of similar size BMX bikes and noticed that they both had those distinctive four-bolt handle-bar clamps and the handle bars with a cross bar on top. Sean and I decided it would be cool to take one BMX bike and flip it up-side down on top of another BMX bike. We'd take the handle bars off of the top one and use its clamp to hold onto the cross bar of the bottom bike's handle bars.

I thought that if we did this, the two seat tubes would line up and I'd be able to put a seat post through both to connect them, but I was wrong. So we took the plastic off of one seat and arc welded the remaining metal wire to the up-side-down bike. This allowed us to connect a regular seat tube to the top bike and slide it into the seat post of the bottom bike. I like to think of it as a bike that has a bike for a seat.

We then had a bike with pedals three feet off the ground, a fork for handle bars, and no place to sit. We solved the handle-bar problem no sweat. We just took another fork and connected it right-side up to the up-side down one. The existing wheel and axle made a perfect connector for the two forks so that's why there's a decorative, fourth wheel on top of the bike.

Now for the real challenge, where do you sit? We both agreed that putting my weight on that little seat-wire-welding number we whipped up earlier would probably cause my death, so we decided to cut the seat tube off of another bike and weld it up right coming out of the bottom bike. To brace it we drilled a huge hole through the bottom bracket of that same bike to put the seat tube through and welded the chain stays to the bottom bike for support. We found an extra long seat post in the yard to toss in there and presto! A very high seat.

Then we realized the major problem. The frame was in the way of running a chain from the crank to the rear hub because it was designed to have the chain go out the back. Now anyone reading this is probably thinking to themselves "Oh that's easy. Put the top bike's chain stays in a vice over night and force them apart. Then stick a five-speed mountain bike wheel with a cassette in the newly widened frame, run a chain from the crank back to the cassette, and finally run a second chain from the cassette down to the rear hub." Now, I admit that, in retrospect, we should have thought of that sooner but it was late and we weren't really thinking all that clearly (which we probably can't blame on the late hour.)

The bike was complete and there was only one thing left to do. I put on some thick gloves in case I had to brace myself during a fall and Nicolle got ready with the video camera in case anything more dangerous happened. As soon as I got on for the first time it was obvious that the bike would immediately do a wheely if I put any weight on the seat. It was so high up that it was behind the rear wheel, causing the seat post to act like a big lever. So we figured what, the heck? Toss a couple 20 lbs. weights on the front handle bars. It's not like we're going to being winning the Tour de France on this thing.

The first few trial rides revealed a flaw in the vertical chain. There was no way to tension the chain so it kept falling off. We added a derailer to try to pull up the slack. This fixed the problem enough to ride but it was still error prone and fell off fairly often causing the bike to lose speed, stall, and ditch its pilot.

We ended up using parts from six different bikes, two whole frames, one extra fork, one set of hacked up frame parts, an extra five-speed hub, a derailer, a seat, and a bunch of spare chains. I admit it wasn't pretty but it was so beautiful. Next time I visit we'll try to fix the chain situation.

10 comments:

Sean said...

you missed a couple fairly crucial points.

1) being totally new to welding, we didn't realize that you can't use an arc welder on thin metal like bike frames very well. this a point that we understand far too well now.

2) brazing can take the place of welding, if you don't have a TIG setup. for certain applications anyway. What is more beautiful than brass? With our application of it, a lot, but ignore that. the later joining work was done by brazing. I don't think I own a propane brazing torch head, but a few acetylene ones, but we didn't have acetylene. So we were brazing with a cutting torch.

3) The balance problem could likely be fixed by changing the front wheel to something significantly smaller. Like one from a small child's bike. We had one, but the tube blew when we put air in it.

Mike Machenry said...

I covered points 1 and 2 in the video so I didn't bother to mention it in the already lengthy writeup.

I did forget to mention point number three and we will need to follow through with that next time I come down as well as fixing the chain.

Do you have any idea how small of a wheel is needed for the front in order to make the seat not be past the back hub?

Jeff said...

That's so totally badass.

I wish I coulda been there to see/help.

I really wanna see this thing in action. I'll do everything I can to make it down next time.

Joe said...

you are a factory of gold. loved the video.

rg said...

Dear Neighbor Mike

Thank you for our Pascualito! He sits on our bookshelf wearing a cowboy hat and holding on to Abe Lincoln paraphernalia. We tried to email you but to no avail, so we should probably just go with tin can telephones and the like. Hope you are well. We are having a bike adventure tomorrow I think if you would like to join.

Number 15
rubygeballe@gmail.com

Nicolle said...

Totally disappointed that I cant make it for round 2.

kaichu said...

OK I have to say this. You guys have some of the most ingenious ideas for having fun that I've come across recently. That bike is a marvel!!

Mike Machenry said...

That bike was a death trap. :) There have been a couple more to come out of the scrap yard since. They are a lot better. One of them I ride to work everyday. Third time's a charm.

Anonymous said...

You could, instead of shift the wheel size or weld weight onto the front, use another frame to extend the wheel base. Also a phantom chain ring as a tensioner will work for the long chain.

pharmacy reviews said...

What a creativity to make a bicycle like this one, I figure out this man spent long time in his workshop creating it, I'm gonna take ideas to make me one.