Rocket Science and Chopper Building

[gww25]

As part of my usual web browsing today I decided that about 75% of the information about chopper building posted on most boards, including this one, has taken a turn towards trying to make an art-form into a mathematical equation. It seems like folks have forgotten or ignored the past and want to go 'high-tech' and bring everything back down to a few well selected sets of technological baselines to come up with 'the proper Chopper that's safe to ride'. I guess folks have forgotten about guys like Cliff Vaughs, Dick Allen, Ben Hardy, Al Grant and Ed Roth just to name a few of the pioneers. Building a Chopper should be an artistic endeavor, even today. Nobody should have to worry about rake and trail. Who gives a shit about numbers when creating something from raw steel? If you can ride a bike with 3-inches of trail you can also ride a bike with 8-inches of trail, you just get used to the different characteristics. If you want to build Choppers you have to break new ground, ignore the 'rules', create something that expresses you own personal ideas and concepts. If I followed the advice I've seen on a lot of boards I'd just be riding a 'stocker' with some glue-on's and a 30-degree rake. If you want to build a Chopper you have to be willing to take some risks, it's as simple as that.

[Dusty-Dave]

Try one with 8" of negative trail. Might be good to think and measure every now and then. I prefer a mix of intelligent mechanic or junior engineer and artist. Course I think most that you mentioned were just that. And don't forget Sugar Bear no just artist or just engineer would have figured out how to make rake numbers like that not flop.
Dusty

[gearhead1951]

Try one with 8" of negative trail. Might be good to think and measure every now and then. I prefer a mix of intelligent mechanic or junior engineer and artist. Course I think most that you mentioned were just that. And don't forget Sugar Bear no just artist or just engineer would have figured out how to make rake numbers like that not flop.
Dusty

Artist+Engineer= Designer !

[curt]

im not a member of any other sites cant say there but I cant figure out the math to save my life but I do try to figure it out some just because I really do love a long bike and I have ridden some crazy bad handling stuff and some really well built stuff . yes you will get used to it ,it is way nicer to ride the well built stuff and I want my stuff to look as good as the old school stuff and still be at least ride able by someone else other than me im not a man of money im going to have to sell it at some point so I can try and build a better , longer , cooler , whatever . I come here because I love the artistry of what you do and yet I want to also learn the technical aspect of people like krymis too . hopefully I can blend the two and make a beautiful bike that I take so much pleasure in owning as well as riding that it becomes an expression of who I am . I don't think the people on this site have forgotten about those guys we just don't have them around to learn from we have to learn about them from the guys like you who had the pleasure of having the ability to learn first hand from them or the people they taught . I can say I myself am fairly new at this and I have been reading everything I can suck into my thick skull from your cds to this site and yours . maybe start some discussions about those guys and how they did things from everything I been reading this site was started because of you and your knowledge of them and their ideas and talent . I for one would love to talk about anything you care to share and id be willing to bet 99 % of the people here would too . just my 2 cents

[rudog]

.... It seems like folks have forgotten or ignored the past and want to go 'high-tech' ...

This is an interesting thought. As a kid, I was real interested in the cars and bikes of the 1800's. The progress from covered wagons to steam power...The huge front wheeled bicycle to Harley and Davidson. The driving force was the power of locomotion. The money, however, was in marketing to lazy people. Henry Ford admitted that his driving force was that he was too lazy to hitch-up the horses whenever he wanted to go to town. His goal was to provide a horseless carraige to the lazy masses.

Non of this motor vehicle stuff took off until some truly brilliant minds engineered the science of how it worked. "ALL" motorised vehicle tires have caster, camber, rake and trail. Someone actually took the time to give these values a name. Yet some values are built into a car while others are adjusted for performance. Bike are exactly opposite. Some values are inherent to it's operation and others need to be built into the frame.

I work steel for a living. I crunch numbers for fun. I would love to know what H-D were thinking when they built their 1st bike. I would love even more to know what they were thinking when they were building their 2nd. There are so many areas of interest in chopper building that there is something for everyone. For me, I've never understood the "Art" of anything. I do understand that DaVinci spent many years perfecting the science of painting.

[neale]

Interesting topic, personally, I think the one who pointed out that the pioneers that were mentioned DID do the engineering (whether by working the numbers or (more likely IMHO) working it in their heads to what was "right", given their understanding of the issue at hand) is right, either way, it was probably part of the job that they didn't feel was worth mentioning, talking to some old engineers and fabricators, often the answer is "that won't work, it'll go all over the place" or something similar, as from trial and error they have the "numbers" in their heads.

At the moment, I'm trying to work up an exhaust for my bike, problem is that I actually want it to perform well, so just going by how it looks ain't enough for me, I had to dig up the info on primary (header) lengths and diameters to get an idea of where I had to go to have the front and rear exhausts to work properly together, same goes for many other elements of the build process IMHO.

I DO hear ya on the artist's viewpoint, however, to me a chopper is an artwork, which is a vehicle as well, which was one of the reasons that I moved on from a "chopper" forum here in Oz, as the guy running it insists on checklists to determine whether something is a chopper, a bobber or whatever, "it's not a chopper unless it has this, this, this and this "a bobber is this, this, this and this", so if it doesn't have pullback bars and a sissy bar it ain't a chopper? Crap! In my world (probably populated by ONLY me, but I'm OK with that You create the image in your head of what you want to build, then you go out and work with the bits until you've got something that fits that image, and works (and, unfortunately, fits within whatever bullshit rules and regulations exist where you are).

Anyway, as most of us have mentioned, interesting topic, thanks

[TattooLeeRoy]

I agree with the "engineer + artist = designer" equation.

Yes, we are all going for the personal vision to creation. Yes, we may build with the intent to sell, or build to ride and sell to finish the next project. Either way, it would be nice if it rode well. Ill handling machines are a chore to ride, and make for fewer repeat or word of mouth business.

If I need to do some math, so be it. I'm gonna run on some empirical knowledge, such as tubing recommendations from experienced builders. I'm NOT gonna do the math to the point of figuring the minimum wall and cross section, cross referenced with materials, yada yada yada... But, basic geometry might just get you and your honey through some emergency maneuver in possession of all your skin.

Even sculptors of pure statuary have to consider the numbers as far as balance and strength go, such as a rearing horse. At no point should the aesthetics of a piece be purely defined by the math, but at the same time, it needs to be a consideration. Or, you may have to repair, and redesign, and do it over. Sometimes you have to change things as other things evolve. You have to let the machine talk to you, and interpret what it says correctly. When you are done the machine is almost alive, you can't do that with pure math.

Of course, this is only my opinion, and I am known to talk to much.

[gww25]

The point I was trying to make, and apparently missed the mark, was that it appears as if many people are being held back in their creative designs by trying to adhere to socalled mathematical 'norms' or 'standards' and not willing to push the envelope to see if those 'norms' are indeed real to begin with. Trail is a good example. Everybody is told to stay within 4" but running 8" on a bike doesn't make it a 'bad' or 'unsafe' bike, it just handles differently. Unfortunately it seems like a lot of people think such a radical design is 'unsafe' because it breaks the 'rules' so they don't try to build one. That's to bad because long bikes are really fun to ride.

[curt]

I think I misunderstood but id still like to hear some stories about why they did the things they did

[jimmib]

Interestnig Topic!
I know how to do all the math to help build something to the norm (I've been doing strutural steel drawings for longer than I want to remember, kinda boring). But what I really love is the art of fabrcation. To conjure up an image in my head and build it! Whether it be bikes, hotrods, racecars or just a pig cooker! What you need is "VISION". If you can't visualize it in your head, you probably can't build it and all the math in the world won't do it for you. Problem is, anymore, whatever you think up has probably already been done!
The old timers, and Gary mentioned a few didn't have all the fancy tools we have today and look what they accomplished. Do you think they ran around and asked everone they new if they had some drawings for a frame or front end? (Remember there was no internet or cell phones).
If I'm a little off topic, just ignore me, comes with age they say!
My $.02, Jim

[rudog]

To make a long story short...The advent of the forums have brought alot of people together. The guys with the experience realised the limits of their knowledge...or simply got tired of answering the same questions over and over andd... This led to the innocuous list of rules that must never be challanged.

How dare you, Gary, try to upset the ballance!

[krymis]

someone mentioned me in one of the posts. Gary worked with me on the "springer rules". that was not a steadfast you gotta build it this way rule book. it was simply my take on why springers operate the way they do with the dropped rockers. many examples have been given of the same rocker geometry but different designs such as sugarbear and chop doc schimitars, denvers and century plain rockers and so on. no real point to my post just wanted to be on this topic...

[yona]

It's like the leafer I had Pete do for me, in cad.... I drew little shapes and looks I wanted and told his to use the basic design of Gary's leafer.... Well, after Pete got the big C, I realized that I had moved to axle to the front and with the trees in the original location .... negative trail !!! but looks good (In my mind) ; )) Then someone said to make a rocker with 2 pivot points back for the leg and use the front for axle and spring links...... I am at this time using wood and making legs with bushings, lexan springs and just square pieces of wood to mock up the trees. I will use screws that just pass thru the wood. that bite in to the trees and hold together with small clamps. This way I can move the legs back and forth on the trees till I get the right trail(+ or - )that works on my trike. The neck will be 10" as the trike is an all-aluminum Caddy N*. I know that the neck can only move so much (+ or -) I also can make my trees wider to see what will work.!! I have built houses since I was in my teens and have worked as a structural steel fabricator since my early 20's ( 65 Now )I was a marine hull repairman in the Army from 68-73.... found out 3 years ago I am Dyslexic, with numbers.... I can't work if someone else is counting and I flip numbers and designs, in my mind. I measure every thing, with my tape in my right hand and extend with my left, never look at numbers upside down ...etc... any way I build custom cars as a day job and build by sight and never measure much, unless I am doing chassis work.
I am a very good woodworker and make wooden surfboards, kayaks, stand-up paddleboards, and canoes....mostly by sight.... My making my frontend in wood, I can actually fit it to the frame and see how it looks and how to change it. I will eventually make it in 60xx or 70xx aluminum, if I can get up the money for material.... Started a post at CW and was told that it was not a smart thing to attempt As the material was not strong enough....some designers and a machinist that did work on the space shuttle. Said I was putting my ass on the line.... I said, it's my ass..... BigJim posted and said " build it " Good enough for me ! Point is I have to build no-tech it's the only way I know ... ; ) I won't ever put up idea's there again....

[hansgoudzwaard]

.. BigJim posted and said " build it " Good enough for me ! Point is I have to build no-tech it's the only way I know ... ; ) I won't ever put up idea's there again....

You seem to have shown that your material was good enough to use for your forks.

I agree, build it.

[rudog]

This is directed toward YONA, but, relates to this thread perfectly. I often play devil's advocate, but, not here.

When I was about 8, my father took me into the city (NYC) to run errends. We visited my uncles shop were he had 20 bridgeports lined up. 40 lathes were being delivered the following week. We visited several of his friends with machine shops. The last place we visited was to return a borrowed tool. The man was missing 3 fingers on one hand and 2 on the other. I couldn't take my eyes off his hands. I wondered how he had lost them and how he could function like that.

He noticed my staring and began to tell me how he lost each of his fingers. It was more than 1 or 2 accidents. As he showed me each missing finger and the way he lost it, he provided a rule he learned from each finger. No gloves with machine tools...always assume the spindle is turning...etc...My father had an odd smile on his face as I listened, but, never said a word.

When we got back in the van to return home, he sighed turned to me and said, "never take safety advice from a man missing fingers." I asked, "Wasn't the advice good?" My father replied, "Yes, but he lost a finger and created a rule. The point is that he never got it in the 1st place. He has no sence of self preservation. The next time he loses a finger he will create a rule. He is limited to 10 rules."

YONA, you have a good sence of self preservation.