Sunday, September 14, 2008

How Choppers Work

Within the motorcyclist community, there's a group of enthusiasts who like to get back to the basics. They want to ride bikes that are powerful, fast and stripped down to the bare essentials. They might take an existing bike and tear it apart, or they might start from scratch to build a bike to their own specifications. They make choppers.
What exactly is a chopper? The definition is fairly flexible, varying from one region to another, but in general, a chopper is a customized motorcycle free of anything that isn't required to make it go -- from windshields and mirrors to front brakes and speedometers.

The history of the chopper begins shortly after World War II. Veterans sought out motorcycles like the ones they saw or drove during the war -- they'd buy a bike and then modify it to make it more like the ones they used to ride. Many of them removed the front fender from the bikes. The rear fender often came in two pieces -- the soldiers removed the rearmost section. They called the new, shorter fenders "bobbed" fenders, and so people who rode bikes with these sorts of modifications were called bobbers.
Later, builders began to make more radical changes to bikes. Many would strip it down to the frame and rebuild it piece by piece. They even began to fabricate parts like custom exhaust pipes or gas tanks to make their own bike a truly unique ride. Some began to call these bikes "choppers," because the owner had chopped up an existing bike to create something new.
Movies like "The Wild One" and "Easy Rider" brought choppers to the public's attention. The 1960s and 70s saw a new generation of chopper enthusiasts. Bikers spent weeks or months trying to create the perfect ride, whether it was designed for comfort, touring, speed or simply to make jaws drop.
In the 1980s, motorcycle companies like Harley-Davidson began to offer what they called custom bikes -- mass-manufactured motorcycles based off the most popular chopper designs. Coupled with an economic recession, this move nearly made chopper culture go extinct. It was only in the mid-'90s that custom bike shops began to flourish again, and today the culture is as strong as it ever was.
Chopper Rake and Trail
Whether you're using a hard-tail or soft-tail, one of the most pivotal decisions you'll make regarding your bike has to do with the bike's rake and trail. You may have seen some choppers that look really stretched out, with the front wheel sitting far out in front of the bike's frame. Bikers can get this kind of look by adjusting the rake of the bike. The rake is the angle formed between the neck on the frame of a bike and a vertical line. The bigger the angle, the further out the front wheel will be from the frame.
The distance between the point where the tire makes contact with the ground and a vertical line from the center of the front wheel's steering axis to the ground is the bike's trail. Trail is measured in inches, and in motorcycles should always be a positive number -- a negative trail means an unstable ride. Trail is important -- too little or too much trail and the bike will be sluggish or even impossible to control. Bike experts all have different opinions on what's the ideal trail length, but it tends to range between 3.5 and 6 inches.
While there's a relationship between a bike's rake and its trail, it's not always obvious. In most cases, increasing the rake of a bike's frame will increase positive trail, though this depends on what kind of fork assembly you use. In order to increase the rake of a bike without making the trail too large, some bikers use raked trees. Trees mount the fork assembly to the neck of the frame and usually have two sets of mounting brackets of equal length. A raked tree's brackets are at two different lengths, allowing the builder to set his fork assembly at a different angle than that of the frame's neck to the vertical.
Once you've got your frame and rake set, it's time to start looking at what you're going to mount on this monster. The world of choppers is full of options, so no two bikes are going to be the same. Chopper builders need to consider how the various parts are going to fit together, whether they'll need to offset components and how it will affect the bike's performance and balance.
Chopper Engines
Bike builders have a lot of choices when it comes to engines and how to mount them. Engines come with names like Evo, Twin Cam, Shovelhead, Panhead and Knucklehead. Some engines work better with certain frames -- in fact, some frames are designed specifically to hold a particular engine. Builders have to be aware of an engine's dimensions to make sure they have the right amount of clearance in their frame once they've installed all their components.
Some builders prefer to mount their engines directly to the frame of the bike as part of the "less is more" philosophy the chopper seems to embody. Engines like Harley-Davidson's Twin Cam 88B come with counter-balancers, which help reduce vibration, making it ideal for those who want to mount the engine directly to the frame. Engines without a counter-balancer system can give off a lot of vibration, so if you mount the engine directly to the frame, all that vibration will affect your ride, making it much less comfortable.
Many builders choose engines based on the look they are going for. Someone building a chopper designed as a throwback to the classic choppers of the '60s will want an engine that looks like an old one. He or she can either purchase an old engine and do some work on it, rebuilding it if necessary, or buy a new engine designed to look like the classic engines of the past. New Shovelhead engines look much the same as they did back in the '60s, but today offer bikers choices in everything from the compression ratio and camshaft to an electronic ignition.
Unlike most car engines, a bike engine's appearance is everything. That's because most choppers don't cover up the engine -- it's on full display. Harley-Davidson offers engines in black and chrome, for example, which usually increases the cost of the engine by about $1,000 over the less flashy aluminum versions.


Chopper Brakes

A chopper's brakes run on a hydraulic system -- builders can choose between disc brakes and drum brakes.
Some bike builders leave off brakes on the front tire-- they say that the back of the bike carries so much weight that you don't need brakes up front. Many others say that all bikes need brakes both on the front and back of the bike, and that when you hit the brakes the weight of a bike transfers forward, increasing the risk of an accident.

How long can you go without food and water?

You sit in your cubicle like a zombie and pretend to look over expense reports. Your stomach growls like a cornered dog. As a test of will and determination, and because you have nothing better to do, you watch the noon hour pass with no lunch. One o'clock, you're feeling dizzy. Two o'clock, you're in a cold sweat. Three o'clock, you're under your desk in the fetal position, sucking your thumb. Finally, you give up and head for the break room to chow on a co-worker's leftover lo-mein. You down a gallon of water like a land-bound carp and finish your day in the bathroom.

At work, you may think you can't go more than a few hours without food and water. Sitting in a discount office chair in your cubicle is certainly no way to test your limits. There are many factors that go into how long a human can survive without food and water, and the will to do so is one of them. Going without water isn't smart, and it doesn't t­ake long before you're suffering from dehydration. Food is a different story. Humans can go quite a long time without food as long as they're well hydrated. Your body weight, overall health and the weather play into the scenario as well. So the answer to the question isn't easy and depends on the person and the situation.

With a spread like this, who'd want to go without food at all?

Japanese Man Hibernates Like Japanese Bear

­In an amazing show of endurance, a Japanese hiker survived for 24 days in cold weather without food and water in October 2006. He thinks he may have tripped and lost consciousness after leaving his fellow hikers. All he remembers lying in a field and falling asleep, then awaking to rescue more than three weeks later.­
His body temperature when he was found was an astounding 71 degrees Fahrenheit -- more than 27 degrees below normal. He had virtually no pulse and his organs had shut down. Doctors believe he may have fallen into a hibernation-like state very early in his ordeal, preserving his brain function and allowing him to survive without any food or water

Living Without Food

The question of how long you can go without food depends on a lot of factors. Will and determination definitely play a part. Political prisoners on hunger strikes and fasting religious leaders have been known to go for weeks at a time without any food. Gandhi fasted for 21 days while in his 70s. People lost in the wild have also survived for long periods of time without eating.
Medically speaking, most doctors agree that healthy humans can go up to eight weeks without food as long as they have water. People have gone longer and been fine, and people have starved to death in less time. Being strong and in good physical shape can help you survive longer, but so does having extra body fat. The body stores energy needed to live in the form of fat, carbohydrates and proteins. The carbs are the first thing to be used up without more food coming in. The fat goes next, which explains why people with more of it can survive longer. Then the proteins go. If you get to the point that your body is using up proteins, basically the body itself, then you're in bad shape.

Indian leader Mohandas K. Gandhi, sitting on a mattress on the floor, surrounded by people at the end of his last fast.
Your metabolism also plays a role. Metabolism is what converts food into energy. If you have a slow metabolism, you'll burn your food intake slower and be able to go longer without replacing the food energy. If you go without food, your metabolism will adjust accordingly and slow down on its own -- basically doing what it can to pitch in for survival's sake.
Climate is a major factor too. The bad news is that both cold and hot weather are no good if you have no food. The good news is that extreme heat and cold will kill you in other ways before you have a chance at starvation. But in terms of living without food, heat means faster dehydration -- cold means more energy is burned to keep the body's temperature at a cozy 98.6 degrees Fahrenheit (37 degrees Celsius). If you're lucky enough to be in mild temperatures, you'll be able to live a little longer without food.



Life Support Patients

­In most cases, when a patient is removed from his life-support feeding tubes, he can be expected to live between 10 and 14 days. If the patient is dehydrated or overhydrated when the removal occurs, this number will vary by a few days.
The famous case of terminally ill patient Terry Schiavo brought this scenario to the forefront in 2005. After having her feeding tubes removed and reinserted several times as a result of a legal battle to keep her alive, a judge ruled that her husband should be allowed to have the tubes removed for good. She finally succumbed to death after nearly two weeks without her life support system

Living Without Water
Now that we've established that food is something we can do without for a reasonable amount of time, we can move on to water. Living without water is very different from living without food. In hot conditions with no water, dehydration can set in within an hour. A baby locked in a hot car or someone who is physically overexerted in the heat without replacing fluids can actually die in a period of several hours.
Humans need water to live, plain and simple. We lose water through sweat, urine, feces and even breathing. This water needs to be replaced in order for our organs to continue to work properly. In severe heat, an adult can lose as much as 1.5 liters of water through sweat alone [source: Scientific American]. The main risk without water in high heat is that your body temperature will continue to rise and you'll suffer from heat stroke. Drinking water will cool you down and lower your core temperature.
The final stage of dehydration is shock. This is characterized by blue-gray skin that's cold to the touch. A severe drop in blood pressure produces this coolness.
Now back to the question at hand. How long can you go without water? Assuming you're in reasonable shape and in ideal conditions -- that is, not in the heat or cold and not exerting, a human can probably live for about 3 to 5 days without any water. Healthier humans can live another day or so longer.
This isn't something you should test. While people may fast or try a body cleanse without food, you should absolutely never go without water for more than a day. The Mayo Clinic recommends drinking about eight cups of water a day, although there's some debate about this number. Some physicians say less is fine, while others say the number should be closer to 10 cups or even more.



Irish Hunger Strike of 1981

In 1981, members of the Irish Republican Army (IRA) imprisoned in England went on a hunger strike to protest their incarceration. Former IRA commanding officer Bobby Sands was actually elected into the British House of Commons while striking, helping to raise awareness for their cause.
­British Prime Minister Margaret Thatcher refused to bend, however. The prisoners drank small amounts of water, but refused food altogether. Sands died from starvation in a prison hospital on the 66th day of the strike. Thatcher remained steadfast and called Sands a criminal and his death a suicide. Nine more prisoners died from starvation after Sands. Thomas McElwee lasted the longest, at 73 total days -- a full week longer than the next closest prisoner.