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Friday
Apr112008

Classic Dutch Bicycle Pictures

I found these wonderful classic Dutch bicycle photos from collector Andre Koopman.

It is a mixture of photographs of this collector's bicycles, plus prints made from the old original glass plate negatives, some dating back to the late 1800s. These came from the Fongers factory, a Dutch bicycle manufacturer.

One of my favorite set of pictures is of a Gazelle bicycle; (Top picture.) it comes with a pretty amazing story that goes like this:

In 1939, a man buys a new bicycle. Soon after WWII breaks out, and with the impending invasion of Holland, man hides new bike in attic. Soon after man becomes sick and dies. Bike remains in attic for the next 64 years.

The unused bicycle was discovered in 2003 and bought by this collector.

Even the original Gazelle tires were still good. The handlebars have a celluloid covering; yes, celluloid the stuff they used to make movie film, and was a forerunner of plastic.

The bike has dynamo lighting; the wiring has rubber insulation with a woven cotton outer casing.

The bike also has a leather dress guard, and a single front brake that consists of a rubber block that pushes down on the front tire.

Pictured below is another bike that caught my interest, and is also from WWII. It is a British made, BSA folding bike that British Paratroopers carried on their back when they parachuted into Holland during the war.

There must have been a large number of these left around the Dutch countryside after the initial drop.

Another even older military bicycle is this 1898 Fongers. (Below.) Looking surprisingly like an Alex Moulton.

I am thinking that the picture got “flipped” and was printed backwards. I have never seen a bike with the chainwheel on the left side. There is no point in this as it would require a left-hand thread on the rear sprocket.

You can view the rest of the pictures here.

My thanks to Bakfiets en Meer, Netherlands who found the pictures first.

Wednesday
Apr092008

A short cycling safety video



I came across this California League Cycling Instructor's bicycle safety video via Philadelphia Bicycle News.

I had to smile at this quote:

“It's duly noted that these are very skilled, faster cyclists interacting with relatively polite Southern California motorists traveling at moderate speeds.”

I’m not sure about Southern California motorists being more polite than in any other state; they have been known to shoot at each other on the freeway on occasions. It’s been a few years since I lived in So.Cal, maybe the threat of gunfire has improved their manners.

Anyway, I digress. I think this short video is excellent and packs a lot of useful information in a few minutes. There was not much here that I didn’t already know, however, just the visual image of cyclists having some control over other road users around them made me feel good.

I realize the video has been edited to serve its purpose, but nowhere do I see the flow of traffic being hindered. The cyclists come across as polite but assertive, and viewers should note that had they just blown through red lights and stop signs, all credibility would have quickly disappeared.

There is a big difference between assertiveness and arrogance. Assertiveness is taking the lane after signaling and making your intentions clear. Arrogance is cutting in front of people, running lights and stop signs, and not only breaking the rules of the road, but breaking the rules of decent human behavior.

Monday
Apr072008

Why are large frames more prone to shimmy?

Over on the Serotta Forum the subject of shimmy was being discussed; this subject is probably discussed on bike forums more that any other. One member posted the following:

“Am I nuts, or do all shimmy prone bikes have one thing in common? Large size frames. I ride a 52cm - 53cm frame. I've never experienced shimmy in any of the many bikes I've owned. It seems like every shimmy story has a tall person in the starring role.”

No, you are not nuts, large frames are more prone to shimmy. First of all, shimmy is a natural occurrence on two wheeled vehicles, bicycles and motorcycles have the same problem.

At a certain speed a spinning wheel will start to nutate, That is, not only is the wheel spinning about its axis, (The wheel spindle.) the axis itself is constantly moving. To demonstrate this to yourself, hold a wheel by the spindle in your outstretched hands, and move your hands in the motion of pedaling a miniature bicycle.

Even a child’s spinning top will hold steady with its axis vertical if it is spinning at speed. One would think it would spin slower and slower until it gently falls over. However, as it slows to a certain critical speed it will start to wobble then fall. In other words, it starts to nutate at a certain speed.

“Rotation” means an object spinning around a fixed axis; “nutation” means the axis is also moving as the object spins. The front wheel is not only fluttering back and forth in the vertical plane, but in the horizontal plane also. Therefore, the head tube of the bicycle or motorcycle is shaking violently from side to side.

The rear wheel does not shimmy because it is fixed withing the frame. Just as on three or four wheeled vehicles the wheels are not prone to shimmy because the axels are held in one plane. Although on older cars, for example, when wheel bearings and steering joints start to wear allowing the wheel’s axis to move, they too will shimmy or wobble at a certain speed.

On a bicycle, most of the rider’s weight is towards the rear. The rider’s weight on the saddle and the rear wheel in contact with the road provide two anchor points holding the rear of the bike steady, while the front end can start to shake violently.

Because the seat tube slopes rearwards, as the frame gets taller the rider’s weight is more directly over the rear wheel. On a large frame this makes for a near vertical pivot line between the rider’s weight on the saddle, and the rear wheel’s point of contact. (See picture below.)

It is about this pivot line that the bike will start to shake, and if the rider then grips the handlebars tighter, his body will also start to shake along with the bike and a crash will probably ensue.

When nutation and the resulting shaking starts, it will only get worse unless speed or weight distribution changes; especially if the rider becomes part of the shaking mass.

On a motorcycle shimmy, (Or tank slapper, as they are called.) they are often so violent the rider is thrown from the machine. In this motorcycle tank slapper video, you will notice the front wheel is not just fluttering side to side about the steering axis, but the wheel is also moving side to side about a horizontal axis, throwing the whole bike and rider side to side.

On a smaller bicycle frame, the rider’s weight is more forward and the pivot line is less than vertical. (See picture below.) This means that even if the rider is riding “no hands” there is still a certain amount of weight on the front wheel.

This is a clue to avoiding shimmy if you are tall and ride a large frame. When descending at speed, move your weight forward and keep your back low so that air pressure on your chest is not forcing more weight to the rear.

Transfer weight from the saddle to the pedals, thus breaking one of the solid anchor points. Often a knee pressed against the top tube will dampen a shimmy. A loose headset may not cause a shimmy, but tightening a headset very slightly may have a dampening effect. Don’t over tighten a headset, or this in itself will make the steering erratic.

This is the third time I have written on this subject, and I don’t want to keep repeating myself. However, it is a subject that will always be around and so will continue to be discussed, and continue to surprise those who experience it for the first time.

In my first article “High Speed Shimmy” I called it a design flaw. This may have been a little strong, but frames I built did not shimmy as a rule, even the larger sizes; so, design and construction do play a role. The only time I was told a Fuso shimmied was when rear pannier bags were fitted, and the frame was not designed for this purpose.

I built my frames with slightly more trail than most other bikes; maybe this factor was enough to prevent shimmy. It doesn’t take much to alter a bike’s handling characteristics. Sometimes different wheels or a slightly heavier tire is all that is needed to stop a bike from shimmying.

I went into the subject in depth in my second piece called “Shimmy Re-visited.” I am now of the opinion that this is not so much a flaw, but a natural phenomenon inherent in any two wheel vehicle. Simply because the front wheel’s axis is free to move in any direction.

All the years I built bicycles, I never gave this subject much thought; I didn’t have to because I never had this problem. I do not have an engineering or science degree, and those who do will no doubt correct me if I am wrong.

I have not written about harmonic vibrations and the reasons why wheels start to wobble, what is needed is not more theories as to why this happens, but ideas to minimize the problem.

Bicycle designers and manufacturers should be concerned, and be looking for a cure. In the mean time, all an individual can do is get to know the limitations of their bike, and ride within those limitations.

Friday
Apr042008

An old friend comes home


In 1982, soon after I started building my own custom frames, I built a 58cm. frame that was somewhat of a showpiece. It was dark blue with lots of chrome.

I am pretty sure this was the frame I posed with in the Masi shop, and was used in one of my early ads. (Left.)

The frame was eventually sold to Bud’s Bike Store, in Claremont, California, and built up as a display model. This bike brought in many other orders, including this one built in 1983.

Then around 1984 this display model was sold, and bought by Lorin Youde. In his own words he told me, “I rode the heck out of it, then for some unknown reason, sold it in 1994.” He added, “Even my wife told me not to sell it, and it was not long after I realized I had made a big mistake.”

Lorin tried to fill the void with other bikes I had also built; he bought this John Howard two years ago.

Then he bought this Recherché in near new condition; it was the one I featured in this post.

Last year Lorin decided to track down the bike he sold. The person he sold it to had resold it, and the bike was in now Spokane, Washington. The new owner had just had knee surgery and so was willing to sell.

A price was negotiated, and the bike returned to it’s original owner at the end of last year. Lorin just sent me pictures. In an email he told me, “I replaced the 8 speed Dura Ace components with period correct Super Record and while not quite in pristine a condition as Chuck Schmidts' it still looks pretty good and is a pleasure to ride.”






Actually, I think the original paint looks pretty darn good for a bike that has “Had the heck ridden out of it.” There are more pictures here.

Tuesday
Apr012008

A new cycling hazard


There is a new hazard for cyclists that has been brought to my attention.

The chances of anyone experiencing this is remote, but never the less it would be remiss of me if I didn’t pass on this information.

It is a strange phenomenon known as Spontaneous Cyclo Combustion. (SCC.) It is similar to Spontaneous Human Combustion (SHC.) but is relatively new.

The first recorded case took place in Southern Italy in 1985, whereas SHC has been around for hundreds of years.

Since the late 1990s there has been a rapid increase in the reported cases, last year (2007.) there were four incidents in the US alone. Two in Arizona, one in Nevada, and one Southern California. SCC seems to be more prevalent in hot, dry climates.

Unlike SHC caused by the melting of body fat known as the "Wicking effect," the cause of SCC is unknown. The end result is the same, the body burns completely, but cyclists have very little body fat, which has scientists somewhat baffled.

Prior to last year, in all known cases, the victims of SCC for some unknown reason, had all been riding alone. In each case the cyclist’s charred remains were found, usually a short distance from their bicycle, as if they had dropped their bike and tried to run from the source of heat before being totally consumed by fire.

However, in one of the Arizona incidents last year there was a witness. Two cyclists, let’s call them Tom and Brad. Tom is deceased; Brad wishes to have his name withheld for reasons that will become apparent. The two were riding in the desert somewhere north of Scottsdale, when Tom the stronger rider dropped Brad on a long climb.

By the top of the hill, Tom was some 300 yards ahead. Brad looked up and saw a bright glow ahead. At first he thought it was a trick of the sun on the hot asphalt, but then he heard cries for help from his friend. By the time Brad reached his friend, his bike lay by the roadside and Tom was fully engulfed in flames some thirty feet away.

Brad grabbed his water bottle and ran to help his friend. However, the heat was so intense he could only get within ten feet of the fire, and in less than a minute all that remained of Tom was a heap of smoldering black ash.

Brad called 911 and while he waited for the police and EMS he took pictures with his cell phone. When the police arrived Brad was promptly arrested on suspicion of murdering his friend. He was held for several days then interviewed by the FBI. After the interview, he was allowed to go home but never told that he was cleared of any wrongdoing. Which is why Brad wishes to remain anonymous.

On arriving home he discovered the pictures he took had been erased from his cell phone. It appears in such cases where some strange phenomenon occurs; our government becomes secretive, and suppresses information.

In the California incident, also last year, it is believed a cyclist who spontaneously combusted accidentally started one of the more serious wild fires that plagued that state. California fire investigators denied it, in what appears to be an official cover up. However, they did say if anyone should catch fire, to resist the urge to run into the surrounding chaparral.

So why the increase in cases of SCC in recent years? Scientists believe it is directly related to carbon fiber frames. It is believed that it is triggered by a build up of static electricity caused by the friction between the plastic saddle, and the polyester fibers in the shorts.

The padding in the shorts is usually highly flammable which adds to the problem, and may even be the primary key in this whole SCC issue. It's like the cyclist is sitting on a fuse to a potential incendiary bomb.

With the old steel frames this static electricity was constantly dispersed throughout the frame. A spokesman for Brooks Saddles in England said, " We have known about this for years, but were afraid to make it public because.......well......we might have appeared a little cuckoo."

He added, "It's the reason we increased the size of the copper rivets in our saddles. (Picture right.) Copper, as you know, is an excellent conductor of electricity and it directs the static electricity away from the danger zone."

So what can a cyclist do to avoid this slight but definite hazard, besides riding a steel frame with a Brooks saddle. Well help is on the way; manufacturers of plastic saddles and shorts are getting together to find which materials do not cause static build up.

It will be necessary to buy the correct shorts to go with a certain saddle. Each will have a warning label, and a code letter. (A, B, or C.) A type “A” saddle must be used with type “A” shorts, and it is not recommended that you mix code letters, or you may be actually be placing yourself at an increased risk.

These new saddles and shorts will not be available probably until early 2009. So what can a concerned cyclist do in the mean time? The incidents are so rare that I am not suggesting cyclists should become paranoid to the extent of carrying a fire extinguisher.

However, there are any number of proprietary flame retardant materials available, that you can use to treat the padding, and make your shorts fire proof. Or, you can simply keep the padding damp throughout your ride with water from your bottle.

There is a website with more information at BlazingSaddles.org