Toray is a brand. Toray 800 is an intermediate level carbon. If they are using T800K then they are most likely using 6K or 12K tow (weave) sizes. Carbon fiber tow is the packaged form of individual spools as produced in the carbon fiber making process. The K value indicates the number of individual filaments within the tow. A lower tow means it is easier to produce and therefore cheaper. The lower the tow, the weaker the frame is because that means it has less fibers per tow. Any of the Toray carbons that start with a “T” are considered high strength. Any of the Toray carbons that start with an “M” are considered to be high modulus. Basically, no matter what a manufacturer calls their carbons, it is most likely either 1K, 3K, 6K,12K or 24K. The main carbon manufacturers are are Toho Tenax, Toray Industrial and Mitsubishi Rayon, all based in Japan.
It may be tough to convince yourself to pay much more for a carbon frame when they all seem to be the same. Dont be fooled my friend; not all carbon is created equal.
Carbon Tow- Bundles of individual carbon filaments
Carbon Weave- Carbon tow woven together to form a sheet
Toray Data Sheet
|T800H||An intermediate modulus, high tensile strength fiber, with high level and balance composite properties. Designed and developed to meet the weight saving demands of aircraft applications. Is used in primary structure of commercial aircraft, including vertical fin and horizontal stabilizers. Available in 6K and 12K tow sizes.|
|T800S||A very cost-effective, high tensile strength alternative to T800H. This never-twisted fiber has especially high tensile properties. Available only in a 24K tow size.|
|Designation||Fiber Type||Number of Filament||Tensile Strength
|Mas per Unit Length
Tensile strength measures the force required to pull something such as rope, wire, or a structural beam to the point where it breaks.
Tensile modulus or elastic modulus, is a measure of the stiffness of an elastic material and is a quantity used to characterize materials.
Carbon is as naturally occurring as steel or aluminum. It is so naturally occurring that we humans are made out of carbon. Carbon is the basic building block of all life forms. The strongest substance on earth diamond is carbon and so is the most fragile one graphite! The amazing nature of carbon is its state and form of occurrence and the ways it can be manipulated to achieve the desired results. It is the 4th most abundant substance on earth, the list goes on..and on!
Now lets talk about how it is relevant to bikes and frame manufacturing? Different manufactures have dabbled with different materials from steel, aluminum, titanium, Scandium and several other materials to achieve what is possibly a light frame and a stiff frame. Light frame and stiff frame are two opposite side of the spectrum and we are trying to get the best of both worlds, so to speak. Of all the materials tested so far , carbon is the most promising candidate that is not only promising to get better but also a proven material. Now, the one down side to carbon is that it does not occur naturally in finished form like other material like aluminum or steel. The carbon we want is attained after a long rigorous process of weaving, oxidizing, laying , drying and re-laying !
Because of the process involved, carbon bike frames are expensive and only the bike manufacturers with most money were able to offer them at first with a premium cost tag. Now, like any other industry the carbon bike industry has come to a place where it is affordable by an average bike enthusiast without breaking your bank. If you are looking for a simple road bike or a hard tail mountain bike frame with no complex shapes and pivot points like the full suspension bikes require, then you are in luck! The best method to achieve those complex rear triangle is by using what is called a monocoque carbon laying. Unlike the conventional frames that rely on the actual internal strength of the material the monocoque construction transfers the actual sheer force to the skin of the frame. So a complex frame design can still be built with no weak links in the frame. The conventional tube to tube construction can be thought of as welding two carbon tubes together, only that is it not welded per say, but bonded under hear with carbon bonding agent and fusing them with heat. This method does not allow for complex design structures to be connected, cause of the amount of bonding material it takes to achieve the desired strength out weights the purpose of carbon frame which is weight reduction.
If you were riding a one-speed, Multi-speed gears can help you climb hills very comfortably which can force you to stand up and “pump” or to get off to push. They also help you to move downhill or with the wind even faster.
What about Cadence? Every cyclist has an ideal “cadence” (pedaling speed), and an ideal resistance from their pedals. While pedaling at your ideal cadence, you have to give the higher amount of power to sustain efficiently. Cadence can be chosen by shifting gears. Your “ideal” cadence will be depending on the slope of the road, the wind conditions, and your own capabilities at times.
When to use high gear and low gear?
“Higher” gears need more resistance on the pedals. If you select a high gear, you will end up a slower cadence. “Lower” gears help the pedals to turn easily, so it becomes easier to spin to a fast cadence. If you had a bicycle which has infinite number of gears, you might be pedaling at the same ideal cadence and with same resistance on the pedals. Obviously, the bike would go slower on the hills, and faster while moving down the hill, but you would not find any difference.
Here is a nice video about understanding bicycle gears!
How to ride a bike, when it really matters?
If you are “Pushing” a high gear where a slow cadence is required, then it will be very difficult, it will be like power lifting. Spinning” a lower gear at a fast cadence is like swimming rapidly. Toe clips pedals make spin very effective. They also enhance one’s safety, because they help your feet to fix to the pedals from slipping. They help them in getting used to these clips, but experienced cyclists may not find them valuable. On a 10-speed bike, the front of the chain runs over 2 “chain rings” or front sprockets which are attached to the pedal cranks. The rear of the chain wraps around 5 sprockets attached to the hub of the rear wheel. The 2 chain rings and 5 rear sprockets give 10 theoretically combinations. This set-up requires two separate gear “derailleur “, one for the front 2 and the other for the rear 5. This is as complicated as gearing a bicycle. A derailleur helps the chain from one sprocket to another in moving chain forward. The front derailleur is a guide to move the chain to sideways. The chain can be moved only sideways while moving forward. So you can only shift the chain of you are pedaling forward. The rear derailleur can be shifted by using the bottom loop of the chain, which is nearer to the derailleur’s pulleys and springs.Try to visualize gear to shift the chain is to its original place, rather than by rote memorizing the positions of the controls of the shifts. The sprockets that are nearer to the middle of the bike (small front, large rear) give the lower gears. The outer sprockets (large front, small rear) give higher gears.
Credits to http://sheldonbrown.com/