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Thursday
Feb142008

Framebuilding FAQs

I received two emails last week with questions on framebuilding. I don't have the time to go into lengthy instructions on how to build a frame, however, I thought I would post my answers here, that way others might find it useful.

I am hoping other readers will find it interesting to know some of the aspects of putting a frame together.

One question was, "Where do I start, do I need to build a jig?" A jig is simply a fixture to hold the tubes in place during assembly, it speeds production if you are building a number of frames all the same.

The frame is not brazed in a jig, for several reasons. The jig would suck up all the heat and take it away from the area you are trying to braze. The jig would obstruct access to all parts of the joint. Metal expands as it is heated and contracts as it cools, if the tubes are firmly clamped in a jig all manner of distortion will take place, and misalignment and built in stresses will be the end result.

The picture that permanently heads this blog is of me tack brazing a frame in a jig. I am heating and brazing tiny spots, just enough to hold the tubes in place. Then the frame is removed from the jig, checked for alignment and held in a vise, with a wooden block around a tube to prevent damage. As the frame is fully brazed the tubes are free to expand and contract as they will.

Jigs only came into wide use in the 1960s, prior to that most framebuilders assembled and pinned the frame together by drilling a small hole through the lug and tube, and inserting a short piece of wire or small nail. The frame was then usually hearth brazed; that is a hearth of hot coals, or one made of fire bricks with the heat applied with a hand held torch. (Picture left.)

With hearth brazing there is less distortion because the whole joint is heated uniformly. For example, the whole bottom bracket shell, seat and down tubes, and in some cases, the chainstays are all brazed at the same time.

The drawback with hearth brazing is that you heat the tubes several inches away from the joint and thereby anneal or soften the tubes. The method I used was to braze with a hand held torch that had a smaller but more intense flame. Working quickly, I could pin-point the heat on the lug only heating the tube barely a quarter of an inch (6mm.) from the lug. This way the tubes retained more of their inbuilt strength, resulting in a stiffer more responsive frame.

On the downside this method causes more distortion. However, by always following the same procedure and sequence, I got to know which way the frame would distort. I would start off with the frame out of alignment, so it would end up in alignment after it was brazed.

When the lug and tube are initially heated they are two separate pieces of metal so not much distortion takes place because the two can move independent of each other. Once you flow brass into the joint the two become one. As the metal cools it contracts and the metal shortens in length so it will pull in that direction. If I begin brazing at the back or center of the lug; there is little or no tube movement at this point because the whole is a triangle holding itself in place.

Then moving clockwise to the left, as the left side cools it will pull to the left; it is still moving to the left as I work my way around to the right. It will move a considerable amount because the right side is not yet brazed and the tube is free to move. By the time I get to the right side and joint is finished; as it cools it will pull back slightly to the right, but not as much because the left side has already cooled and is solid.

So you can see that the tube needs to be slightly offset to the right to compensate. I cannot tell you by how much because it depends on the speed of the operator and the amount of heat used.

As for brazing the rear triangle. I would finish and clean up the main triangle, then assemble the rear triangle separately, by brazing rear dropouts into chainstays, and next the seatstays to the rear dropouts. Then cut to length and braze the top caps to the seatstays. After clean up, I would then braze the rear triangle to the main triangle.

The same alignment problems exist for the rear triangle. If I tack braze the right side first, it is already contracting as it cools and the wheel center is moving to the left. (Viewed from the rear.) Now when I braze the opposite left side one would suppose that it would then contract as it cools and the wheel center back to center, but this is not the case. Because when I tack braze the right side, the left side is preheated so brazing the second side takes less time, and the left side contracts at a lesser rate.

Again the wheel center has to be set slightly to the right to compensate. When the initial tack has been made and allowed to cool; if the wheel center is off, the tack can be reheated to a dull red. This is not enough to melt the tack, but the brass becomes plastic at this temperature and can be moved in the desired direction to bring it into alignment. Bearing in mind that it will again contract on cooling so it is again necessary to over compensate. Once alignment is correct the seatstay caps can be fully brazed to the seat lug and the rear triangle will stay aligned because each side will expand and contract back to its original position.

I did not pin my frames, I assembled and tacked them in the jig and my brazing method did not allow the tube to move, because part of the brazing was cooling as I moved around the joint. It is only necessary to pin if you have no jig, or if you are going to heat the joint completely in a hearth and the tube might move as a result.

I also used my jig as a design tool; I could set up the jig to see if a design was feasible before I even started cutting tubes to length. Today you can do the same thing on a computer, making a jig unnecessary if you only plan to build one frame. It might be a good idea to do a full size drawing on a sheet of plywood or sheetrock, or at least a chalk outline on the floor so you can lay the frame on it for reference as you progress.

Some of the old time framebuilders used to braze the head tube to the down tube first using the bottom head lug. By measuring the angle with a protractor and ensuring this was correct to the drawing, everything else would fall into place.

Pinning the frame alone will only ensure that the tubes do not slip in or out of the lugs, the whole assembly will flop around like a jointed wooden puppet. You will need to braze each pin in place, in other words tack it. Then you can check for alignment, and the tubes will move on the pin and tack and stay where you place them. This brings me to the second question I was asked.

Why pin in the center of the frame? Could a pin be placed in the side of a bottom bracket for example. I have already explained if you tack on one side the tube will move in that direction as it cools. You would have a hard time realigning the frame as it would always have a tendency to move towards the original tack. Pinned and tacked in the center, you can move the tube either way to align it.

How about a pin on the right side of the bottom bracket to hold the tube as you braze the left side? Not a good idea. As the left side cools it will still pull to the left, and the pin will now be under stress. As soon as you apply heat to finish brazing, the bottom bracket shell will crack.

Should you use brass of silver? I always used brass, as did most European builders. Brass is easier to use, it melts when the metal is orange-red. If you go beyond to yellow you are too hot. Heat is controlled by constantly moving the torch. Even if you use silver, you will still need brass to braze the dropouts into the chainstays, etc, as silver is no use for filling large gaps.

A question I know will be asked. Why do I have a small hammer in my right hand along with the brazing torch? (Top picture.) If there is a small gap in the lug as I braze, I switch the torch to my left hand and keep the heat applied as I tap down the edge if the lug with the hammer. Then switch back and continue brazing.

There is a previous article I wrote on simple frame repairs, replacing tubes in a damaged frame is a good way to practice and learn framebuilding skills. I also mentioned some frame design software here.

Monday
Feb112008

Friends


Hollywood celebrities Courteney Cox (Left.) and Jennifer Aniston (Right.) stars of TV sitcom “Friends,” are it appears, real life friends.

When Jennifer mentioned she would like to take up cycling, Courteney rushed out and bought her a $12,000 Chanel Bike.

Steve, AKA the Maltese Falcon, a regular reader and commenter on this blog, sent me a link to the story.

At first I thought this is one of those nothing, no-news stories, then I thought why not have some fun with this. I imagined the conversation the day after the sale, between the Chanel store that sold the bike, and Chanel’s corporate office.

The conversation would go something like this.....

“Hello, is this Chanel Corporate Purchasing? This is Tyrone Schoulaces, manager of the Chanel Store, on Rodeo Drive. We need to order another Chanel bicycle.”

CORPORATE PURCHASING: What do mean another one, there is no other one, that bicycle is one of a kind. We’re talking about the $12,000 bicycle, right?

TS: Yes we sold it and we need another one. Courteney Cox came in a bought it for her friend Jennifer Aniston.

CP: You did what. You weren’t supposed to sell it, that is why it was $12,000. We figured the type of people who can afford $12,000, do not ride bicycles.

TS: I don’t understand, it was in my store with a price ticket on it, so I naturally thought it was for sale.

CP: No darling, we are in the fashion, perfume, and bag business, not the bicycle business; what are you going to do if they bring it back with a flat tire, or the brakes need adjusting?

TS: So why offer a bike?

CP: It was a publicity ploy. We announced at the end of last year we had a bicycle for $12,000. Then we took a bicycle you could buy at any bike store for what? $600 tops. Stick an already overpriced Chanel bag on the back, say another $300, and there you have it a $12,000 bicycle. Vogue and all the other fashion magazines just lapped it up.

TS: I remember reading that, Vogue said was $6,000.

CP: That’s when we realized someone might actually buy it, so we doubled the price. Of course it never occurred to me that some celebrity would want to show off and buy it as a gift for another celebrity. We should have tripled the price.

TS: So what’s the problem? Just get another bike.

CP. It’s not that easy; that bike came all the way from Holland, or Nederland, or some other ‘behind the times’ place were they haven’t discovered the internal combustion engine, and people ride bikes all the time. Actually, the bike was made in China, shipped to Holland, then here.

TS: So that bike had been three-quarters of the way around the world.

CP: Exactly, and now it will be lucky if it goes three-quarters of the way around Beverley Hills.

TS: I thought all these Hollywood types were going “green.” You know, global warming and all that.

CP: Oh yes, they support it, and talk about it, but let's face it, they are still going to drive their Hummers and Limos. In fact all the hot air coming out of Hollywood about global warming, is actually contributing to global warming.

TS: So what are we going to do about the bicycle? There’s a large void, in my window where it used to be.

CP: Okay darling, here’s what you do; you get it back. It wouldn’t surprise me if Courteney Cox and Jennifer Aniston chipped in six grand apiece, and cooked this whole thing up as a publicity ruse themselves.

TS: Do you really think they would do that?

CP: Of course, what with Courteney not working much, and Jennifer’s break-up with Brad being ‘old news,’ they are probably trying to drum up some residuals from TV re-runs of “Friends.”

TS: I wondered about that. What kind of a person spends $12,000 on a gift for a friend, then blabs to the media about how much she’s spent. So how do I get it back?

CP: You contact Courteney Cox and offer to buy it back. If it is a publicity stunt, she’ll jump at it. If Jennifer really wants to take up cycling, buy her a decent bike from any LA bike store, and ask if you can borrow the Chanel bike for display until the end of the year. Offer Courteney and Jennifer a year’s supply of bags and perfume.

TS: But why do you only need the bike until the end of the year?

CP: Because by that time bikes will be so last year, and we’ll think of some other bull-shit idea to get millions of dollars worth free publicity.

TS: I’ll take care of it.

CP: Thanks, chow darling.

Friday
Feb082008

Memories


Today is my birthday. As a kid birthdays were important, then as the years went by they mattered less and less. Now I am much older they have become important again. I guess it has something to do with the sense of achievement in having made it thus far.

People say I look good for my age. That is because I was born at a very early age and have remained young ever since. That’s me in the picture above; the earliest picture I have of myself. Taken in 1936 the year I was born.

I have a memory from about the same time the picture was taken. I know that sounds strange or even impossible, but this memory has always been with me throughout my life. I even have memories of having this memory throughout my childhood. So I know I didn’t imagine or dream it in later life.

My memory is of being with my mother; we were outside and it was a bright sunny day. My mother was standing at the end of a garden, holding me, sitting up in her arms. We were looking over a hedge into another garden.

The most likely assumption is that this was at the back of our house in Surrey, England, so therefore we were looking into a neighbor’s garden. Someone some short distance away was calling “Coo-eee, coo-eee.” My mother was saying to me, “Look, look over there.” She was pointing at the same time.

In part of this memory I was in this little body (The one you see above.) and part of the memory I was out of my body, about fifteen feet to the left, and slightly elevated. I was looking at myself in my mothers arms.

This is the only ‘out of body’ experience I have had, it has never happened since. I can still picture the scene now as I write this. I could hear this person calling, “Coo-eee,” and I watched myself, my head was straining forward to look and listen. My eyes big and round, and my head kept jerking this way and that every time my mother said, “Look, look over there.”

Suddenly, I was back inside this little body, looking out. I can even remember my thoughts at the time. I was thinking, “Who the fuck is calling Coo-ee?”

Now this in itself is interesting, because obviously I had not learned to talk at this time, much less learned the “eff” word. However, I have come to realize that memories of thoughts are in words, and even though I couldn’t talk back then, I have since added the words to describe the feeling of frustration at not being able to see the person calling out to me.

Language is both the gift, and at the same time the curse of human kind. A gift in that I can retain a memory such as this, and even share it with others. It is also a curse in that we tend to hold on to the bad memories and relive them, along with the accompanying emotional pain.

A friend of mine recently had a heart attack at age 40. He knew there was something seriously wrong, and called 911. When the ambulance arrived, he walked out of the house and then collapsed. His heart and breathing stopped, but the paramedics revived him.

He has since made a full recovery, and was recently telling me of the experience. He described an ‘out of body’ experience where he was off to one side and slightly above the scene, watching himself and the paramedics as they revived him.

His experience sounded exactly like mine; convincing me still further that it actually happened. It matters not that you believe my little story, but that you found it entertaining. It will always be real to me.

The weather forecast today calls for sunny skies and temps in the 60s, here in South Carolina, much like the day I was in the garden with my mother. I will be going out for a bike ride later; burn off some calories and make room for cake.

Wednesday
Feb062008

Some late thoughts on the late Sheldon Brown

Like most people I never got to meet Sheldon Brown. After reading many online tributes yesterday, this morning I did a Google blog search and came up with around 3,700 blog entries on Sheldon’s passing.

Then I did another search for blogs on Heath Ledger, the young movie star who died two weeks ago, 148,000 blog entries. A ratio of 40 to 1; however, when you consider Heath Ledger was an internationally known movie star, and Sheldon was a bike mechanic; I still find this statistic pretty amazing.

Heath Ledger died two weeks ago and Sheldon Brown passed away last Sunday. The number of blogs on Ledger would have been considerably less just two or three days after his death.

When you also consider Heath Ledger’s death, and the drug related speculation that followed, was all over the media; whereas, the news of Sheldon’s passing broke on a few bike related websites.

The point I am making is this: You can measure a person’s greatness by the number of lives they touch; Sheldon Brown surely touched many lives.

The most common word used to describe Sheldon is “Guru.” It is a word that often gets misused, but in Sheldon’s case fits perfectly. There are leaders in this world, and then there are gurus.

When leaders speak, not everyone agrees; some don’t like the way they are being lead, and they protest and argue. However, when a guru speaks, people just listen in silence and nod their head in agreement.

Sheldon regularly posted on Bike Forums; he will be greatly missed there. His last posting on February 3rd. he helped someone who had a question on freewheel threading.

No one ever argued with Sheldon on Bike Forums, they just quietly nodded their heads in agreement.

This is rare, anonymous posters anywhere on the Internet are not opposed to telling someone they are “full of shit” when they disagree with something.

Leaders often demand respect, but in the end they have to earn it. Gurus never even ask for respect, they come by it naturally. A rare quality indeed; Sheldon Brown had that quality.

Monday
Feb042008

NelsonVails


February being “Black History Month” I thought I would touch on a piece of history that is just twenty, some odd, years old.

In the 1984 Olympic Games, held in Los Angeles, a young black cyclist who grew up in the projects of Harlem, in New York City, won a Silver Medal on the track in the 1,000 meter sprint.

I get the feeling that there are many cyclists out there who have never heard of Nelson Vails, or if they have heard of him have allowed the memory to slip into the far reaches of their memory banks. As for the rest of the population, who remembers a silver medalist in an obscure sport like sprint cycling?

I remember because I met then 19 year old Nelson Vails in 1979, or early 1980 when I worked for Paris Sport in New Jersey. I worked in the frameshop at the back of Park Cycles, a bike shop owned by Vic and Mike Fraysee. Just seven miles from Manhattan, over the George Washington bridge, cyclists from New York City would ride the bike path over the bridge to visit the bike store.

It was on such a visit that Mike Fraysee brought Nelson down to the frameshop and introduced him as an up and coming young bike racer. Later on many trips I made to Lehigh County Velodrome, near Allentown in Pennsylvania, I got to see Nelson Vails race.

Nelson was the youngest of 10 children and grew up in Harlem; he was a bicycle nut by the time he reached his teen years.

Entering races in Central Park and at the bumpy, aging velodrome in Queens, he raced with an assortment of miss-matched cheap equipment, and worn out clothing with holes. He wore a pair of second hand cycling shoes that were too big for him, but in spite of this would hold his own against well-trained athletes on better equipment.

By aged 19 Vails was married and had children of his own; he had to make a living. His natural choice was that of a bike messenger in Manhattan. Bike messengers carry everything from letters and jewels to wedding gowns and baseball uniforms, all over the town, at terrifying speed.

The more packages a messenger carries in a day the more money they make. They learn to ride at the speed of traffic when it is moving, riding in the slipstream of delivery vans. Squeezing through narrow gaps in traffic whenever it is stopped or moving slow.

One would think an eight or ten hour shift as a bike messenger would be training enough, but Nelson would ride 40 miles in the morning before work, and he would also ride on weekends.

All this training, plus the turn of speed he developed on the streets of Manhattan took him all the way to a place on the US National team in 1982. He won a Gold Medal in the Pan American games, held in Venezuela in 1983.

Then in 1984 came disappointment when Nelson was beaten by Mark Gorski in the Olympic trials. The structure of the 1,000 meter sprint event was that only one rider from each country could compete.

Then world politics took over and changed the fate of Nelson Vails. The Russians dropped out of the Olympics and this opened up a spot for one extra rider. The Olympic finals was a repeat of the trials earlier; Mark Gorski won the Gold, and Nelson Vails the Silver. Tsutomo Sakamoto of Japan took the Bronze.

What I remember about Nelson Vails was his personality; always smiling, always joking. His attitude on the track was the same as when he was a bike messenger in Manhattan. “Stay out of my way; I have a job to do.”

In 1986 Nelson made his acting debut in the movie “Quicksilver” starring Kevin Bacon. Appropriately, a story about bike messengers; he was cast as “Messenger in Maroon Beret.”

Nelson Vails has my utmost admiration. He came from a poor and underprivileged neighborhood in Harlem, and despite this, through hard work and determination made it to the top, in what could be seen as a middle class white man’s sport.

The last I heard Nelson was living in Boulder, Colorado; still riding his bike, cycling in recreational tours across the country. You can read more about Nelson Vails on BlackAthlete.com.


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