Thursday, January 29, 2009

building a bmx bike..

part 1.

part 2.

part 3.

part 4.

Tuesday, January 27, 2009

choosing a tread..

SLICK TIRE

Many bike tires made for street use are slick. The tires appear almost smooth with a barely perceptible tread pattern. These are mainly designed for city touring or for commuters. 

SEMI-SLICK TIRE

Somewhere between knobbies and slicks, these tires are designed with a smooth center, for minimal rolling resistance and faster acceleration, and aggressive treads on the side to help with cornering.

INVERTED TREAD 

Tires designed with an inverted tread have less rolling resistance than those with any type of regular tread, but offer more grip—and rolling resistance—than slicks. Use these tires if you suspect you might venture off asphalt or ride on roads with lots of ruts and potholes.

KNOBBY TIRE

Different knobby tread styles are designed for specific trail situations.

  • Smaller knobs are faster and suitable for smooth singletrack.
  • Taller knobs offer more grip in technical terrain like roots and rocks.
  • Wider tires with sturdy paddle-like knobs are best for soft trail conditions.
  • Knobs that are wider at the base will corner better on hardpack.
  • Tires with tall, widely spaced knobs offer versatility in loose and hardpacked conditions.
  • Tires designed for mud have widely-spaced knobbies so that mud sheds from the tire. 

- www.rei.com

Saturday, January 24, 2009

the world's lightest marathon/trail bike..

SCOTT GENIUS 2009 Bike.

The World's Lightest Marathon/Trail Bike with 150mm travel.

Wednesday, January 21, 2009

preventing flat tires..

Products that can help you prevent from getting flats..

TIRE SEALANT

This is a non-toxic goop that you put inside the tube through the valve system.  It automatically seals small punctures.



TIRE LINER

A tire liner is a long strip of tough material that you put between the tube and the tire. 



Thorn-Resistant Tubes

These thick tubes provide more protection against punctures.

KEVLAR BEAD TIRES

These kind of tires is great at resisting punctures. The main disadvantage is a slightly harsher ride, and the fact that it's a bit hard to get the tires on and off the rims since they're so stiff. Kevlar beaded tires are lighter and often are made with higher quality rubber than the wire bead versions. If you're going to use only one anti-flat product (instead of a combination of products), this is probably your best bet. 


AIR-FREE TUBES OR TIRES

These are semi-solid rubber, with no air, so they can't go flat. One can get either an air-free tire, which replaces the whole tube & tire (e.g. Greentyre), or an air-free tube, which fits inside one's existing tire.



Any one of these products by itself may afford some protection, but using more than one can become a powerful combination. 

Saturday, January 17, 2009

bike pedals..

A bike pedal is the part of a bike that the rider pushes with his foot to propel the bike. It provides the connection between the biker's foot or shoe and the crank allowing the leg to turn the bottom bracket axle. Pedals usually consist of a spindle that threads into the end of the crank and a body, on which the foot rests or is attached, that is free to rotate on bearings with respect to the spindle.

Flat and Platform Pedals 

Platform pedals are pedals with a relatively large flat area for the foot to rest on, in contrast to the quill pedal which has very little surface area. In mountain biking and BMX, platform pedals typically refer to any flat pedal without a cage. MTB and BMX riders prefer platforms to cage pedals because they offer more grip using short metal studs, are rounder and do less damage to a rider's shins and ankles during an accident. Cage pedals often scrape skin and flesh off the shin if the rider stops short and loses footing of the pedal.

Quill Pedals

Cages refer to pedals that can accommodate toe clips and not necessarily the clips themselves, and are more specifically called quill pedals. The actual cage is the outer part of a conventional pedal, the part that comes in contact with the rider's shoe and has holes where toe clips can be secured by screws. Toe straps used with clips further secure the foot to the pedal and to allow the cyclist to apply power on the upstroke by pulling against the pedal. The main difference between track, road, and touring quill pedals is width. Track pedals are narrow and the front and back plates of the cage are separate, road being a little wider with a one piece cage in a shape of a sideways "U", and touring being the widest to allow for comfort when used with wider, non-racing shoes during longer rides.

Clipless Pedals

Clipless pedals (also clip-in or step-in) require a special cycling shoe with a cleat fitted to the sole, which locks into a mechanism in the pedal, holding the shoe firmly to the pedal. Most of today's clipless pedals lock to the cleats when stepped together firmly, and unlock with when the foot is twisted outward. Clipless refers to the lack of an external toe clip (cage), but not to be confused with platform pedals without toe clips.

- Wikipedia

Thursday, January 15, 2009

choosing a mountain bike handlebar..

Handlebars come in a variety of types designed for particular types of riding.

Drop

Drop handlebars, as used on road or track bicycles, may have a shallow or deep drop. Drop bars may have one or two longitudinal indentations so that the brake and shift cables protrude less when they are wrapped under the bar tape. They may also have a flattened (ovalized) top section to provide more comfortable support for the hands.

Syntace Racelite 2014, Drop Bar, Medium, Black 42cm

Track

Track drop bars are a variation of drop bars designed for the typical riding positions of track bicycle racers. Track drops are characterized by large, sweeping ramps, effectively precluding the top and brake hood hand positions, but promoting the rider's use of the ends, or "hooks". Track bars are designed for use without brake levers, but recently experienced a surge in popularity on use with fixed gear bikes, and as such are have been adapted to fit levers and hand positions.

Nitto Track 40cm 25.4 Alloy Silver bar

Touring or Trekking

Sometimes referred to as "Butterfly" bars, these are commonly encountered in continental Europe. They typically consist of a broken figure-of-eight arrangement mounted horizontally on the stem. This style of bar allows the rider to remain relatively upright while at the same time providing a wide range of hand positions for comfort on long duration rides.

Pyramid Touring North Road Alloy Bicycle Handlebar

Ergo or Anatomic

The shape of the drop may be a simple, traditional curve, or it can have a flat spot (straight section) which some riders find to be more comfortable for their hands. These bars may be described as ergo or anatomic.

Easton EA50 Ergo Road Cycling Handlebar - 31.8mm


Drop-in

At one time, manufactures and racers experimented with drop-in bars that had an additional extension in toward the head tube at the rear end of the drops. This was intended to offer an even more aerodynamic position, due to low and narrow placement of the hands, than just the drops, while still remaining legal for mass-start races. Their popularity has since waned.



Flat or Riser

"Flat" or "riser" bars are the standard handlebars equipped on mountain bikes, and recently on fixed gear bicycles. Flat bars are comprised of a nearly-straight tube, slightly bent toward the rider. Risers are a variation in which the outer sections of the bars rise from the center clamp area. Flat and riser bars may be appended with bar ends, providing more hand positions.

Ritchey Comp Flat MTB Handlebar, 580mm 25.4mm Black

Upright or North Road

North Road bars are swept back toward the rider, with each grip ending nearly parallel to each other and the bike. This type of bar was equipped with three-speed and single speed Raleighs, Schwinns, and other three-speed bikes well into the 1980s, as well as various European utility bikes and roadsters. They have recently enjoyed a resurgence in popularity on some hybrid bicycles, city bikes, and comfort models. They are also known as "Townie", "Tourist", or "Comfort" bars.

Triathlon or Aero

Triathlon bars or aerobars include various styles of aerodynamic handlebars for racing bicycles and particularly time trial bicycles. Included are narrow, bolt-on extensions that draw the body forward into a tucked position, pursuit bars that spread the arms of the rider but drops the torso into a slightly lower position, and integrated units that combine elements of both designs. These are commonly used in triathlons and time trial events on road and track. However, they are illegal in most mass start road races or any other event where drafting is permitted because, while aerodynamically advantageous, they tend to draw the hands away from brakes, make the rider slightly more unstable on the bike, and can be dangerous in the event of an accident.

Profile-Design T2 Clip-on Aerobar

Pursuit

Pursuit bars, or Bullhorn handlebars, curve forward away from the rider. They are often used with dedicated triathlon bars and are also popular, by themselves, on track, single-speed, and fixed-gear bicycles.



- Wikipedia

Tuesday, January 13, 2009

what kinds of components do i need for my mtb?

Most mountain bikes have Shimano shifters & derailleurs. SRAM is the other main vendor. Shimano makes a wide range. Below are some models of Shimano rear derailleurs.



SHIMANO TOURNEY -  Mainly designed for riding around the neighborhood.


SHIMANO ALTUS - Sufficient for paved or very easy trails; avoid hills.


SHIMANO ACERA - Slightly better, but won't shift well under stress; capable for easy casual riding.

SHIMANO ALIVIO - Minimal capable for recreational riding; will handle some hard riding.


SHIMANO STX / DEORE - Entry-level components for hard riding; tough & reliable.


SHIMANO LX - The minimum standard for hard riding. Reliable & responsive.


SHIMANO XT - More responsive than LX, but still reasonable tough.


SHIMANO XTR - Light, responsive racing components; tend to be quite expensive; often sacrifices toughness for responsiveness.


Look for a component set that fits your expected riding style.

Thursday, January 8, 2009

folding bikes..

A folding bike is a bike that incorporates joints in the frame and handlebar stem that permit it to be broken down into a more compact size. Most of these bikes have wheels of 20 inch (51 cm) diameter or less. Folding bikes can be taken on public transport and into apartment buildings or workplaces where conventional bicycles are not allowed. This facilitates mixed-mode commuting, because a folding bike need not be parked in the street or train station. Folding also makes it easier to transport a bicycle in an automobile.



Folding bicycles often cost more than non-folding bicycles with the same performance-related features, because they have more parts, to allow folding and to lock the frame when unfolded. This results in a more complicated design, which is more complex to manufacture; as well, there is a smaller market for this type of bike. 

Folding bicycles are as safe as standard bikes, possibly safer. Naturally, some bikes are better made than others but this has less to do with the type of bike and more to do with the bike manufacturer.

Based on several folding bikes reviews and websites, Brompton and Dahon models seem to be the best folding bikes. These folding bikes fold quickly and easily. They are not bulky. They are ideal if you are traveling by train or bus and want to bring the bike on-board.

If you are looking for a high-performance road bike check out the Airnimal or the Bike Friday. These bikes are used worldwide for long-distance travel. Many cyclists who have tried these bikes found them to be an ideal mixture of performance and convenience.

Most folding bike manufacturers are producing high-quality products, but the issue of quality is not necessarily the measurement everybody uses when seeking out the best folding bikes.

- MetaEfficient.com

- FoldingBikes.net

Wednesday, January 7, 2009

mountain bike maintenance tips..

1.     Remove accessories on the top of the handlebar. This includes the lights, bell, etc. If your bike has V brakes, release the brake cables. Starting with the front brake, push the two brake calipers into the rim of the wheel to release the tension from the cable. Then lift the brake cable up out of the retaining clip and repeat with the rear brake cable.

2.     Turn the bike upside-down. To protect your grips and saddle, lay out an old towel or something similar on the ground (or fork out the hundred bucks or so for a repair stand). Standing beside your bike, lean over it and grip the frame with your hands - one hand on the down tube at the front and the other hand on the seat post at the rear of the frame. Then lift up the bike and turn it over.

  • Alternate method: Hang the bike from the saddle. To protect the underside of your saddle, pad the tree branch, rafter, etc. Hanging the bike right-side-up is a better method as the chain sits in a specific location due to gravity pulling it down.
  • Another Alternate Method: String it up. Hang the bike from a balcony by stringing rope around the handle bars, up to the balcony, and down around the seat stay

3.     Remove the wheels. Open the quick release lever on the front wheel axle and lift the wheel out. Remove the rear wheel - open the quick release and, as you lift up the wheel, ease the rear cassette housing out of the dérailleur mechanism (the part with the two cogs).

4.     Clean the drive system. Using the brush and some soapy water, start by cleaning the rear derailleur, working the brush into all the moving parts.

  • Turn the pedals to move the chain round and, holding a wet soapy rag around the chain on the rear derailleur, give it a good wash down.
  • Use the brush with plenty of water to clean the chain ring (the front cog where the pedals attach). Then give it a wipe down with a dry cloth.
  • Taking a wet rag, wash the pedals and then wash the cranks (the bars that hold the pedals on).
  • Finally, clean the front gear mechanism, working the rag into all the moving parts to clean them thoroughly.

5.     Wash the underside. Start by washing the front forks with a rag and soapy water, wiping them dry with a cloth as you go. In the same way, clean the centre and rear of the frame.

  • Wash the handlebars with a soapy rag, paying particular attention to the brake lever and gear assembly.
  • Using a damp rag, wash the top tube or crossbar, making sure to clean under the brake and gear cables that run down its length.
  • Finally, clean the underside of the saddle.

6.     Wash and remount the wheels. Take a wet rag and start by cleaning the rims of the front wheel. Give the spokes a wash-down and clean the axle. If you have a disk brake system, use a degreaser, such as muck off or white lightning to clean the disc's.

  • Drop the front wheel back into the forks and tighten the quick release - not too tight, not too loose. When you have tightened the lever to the correct pressure, the quick release will leave a mark on your palm for a few seconds. If you need to adjust the tension of the quick release, turn the nut on the far side of the axle clockwise to tighten it, or anticlockwise for less tension.
  • Take the rear wheel and clean the rims, spokes, axle and rear disk rotor if you have one, as you did with the front wheel.
  • Clean the gear cassette on the rear wheel carefully. Use the lever end of the bike brush to remove any stones between the teeth, then work the brush into the cogs, using plenty of soapy water. This will remove any build-up of lubricant or dirt.
  • Drop the rear wheel back into the frame, easing the gear cassette back into the derailleur assembly. Tighten the quick release.

7.     Check the wheels. Spin each wheel, making sure it turns freely and that you can see that it's straight (true). As the wheel rotates, hold your fingers against the rims, to feel if there are any dents or knocks on either side.

  • If you have disc brakes, also check both sides of the rotors on each wheel for true. Make sure it looks smooth and straight. Do not touch the rotor.
  • If you have V brakes, watch the wheel while it's spinning, to make sure that the brake blocks do not make contact with the rims.
  • Check the spokes by turning the front wheel slowly and letting your hand fall over each spoke as the wheel rotates. Every spoke should feel taut but if one feels sloppy, it will need tightening.
  • While the bike is still upside down, check the tire pressure and that both tires are in good condition. If you find any major damage, replace the tire before your next ride.

8.     Check the drive system. Check both pedals by spinning them, making sure that they turn freely and that there is no noise or grinding from worn bearings. If there is, you'll need to replace the bottom bracket.

  • Turn a pedal to rotate the crank and listen out for any noise or signs of wear from the bottom bracket (the assembly that holds the cranks and chain ring in place). If you find any, it will need further maintenance.
  • Check the front gear mechanism. Turn the pedal and move the chain up and down the gears using the gear lever. You're looking and listening for signs of snagging, which happen when the mechanism is misaligned and needs adjusting. Do a similar check with the rear derailleur and gear cogs.

9.     Wash the topside of bike. Stand by your bike and grab the frame with both hands as you did before to turn your bike back up the right way. Then lean the bike against a wall.

  • Using a clean rag and soapy water, wash the handlebars and the headset (the part where the handlebars meet the frame). Take care to clean well around the brake and gear levers. Wash the tops of the forks on the front wheel and, if you have front shocks, give the seals a good wipe down.
  • Moving to the centre of the bike, clean the down tube and the top tube or crossbar.
  • Open the quick release to remove the saddle. Wash the saddle tube and the seat post on the frame, then remount the saddle, tighten the quick release and give the saddle a wipe over.
  • Finally, clean the seat stays (the two tubes that join the seat post to the rear axle) and wash around the bottom bracket.

10.     Check the brakes. Test your brakes by standing in front of your bike, holding the handlebars. Apply the front brake and pull the bike towards you. The front wheel should not move at all and if you continue to pull, the rear wheel should lift up off the ground; otherwise, the brake will need adjusting.

  • Do the same test with the back brake. When the brake is applied, the rear wheel shouldn't turn round and if you keep pulling, it should skid. If not, the rear brake will need adjusting.
  • Also, look at the brake levers - the brakes should start to grip at about 1/3 pull. The levers should not touch the handlebars. If they do, your brakes need adjusting.
  • f you have disc brakes, check that they are in good condition by standing in front of the bike and looking down inside the disk brake caliper (the bit that fits around the brake rotor). Apply the front brake and you should see both brake pads move across equally to clamp the rotor. If they don't, this indicates a problem. Repeat the above test with the rear disk brake, standing where you can see down into the rear caliper.
  • If you have V brakes, check the brake blocks for signs of wear. They should be free of graphite build-up, and the grooves in the pad should be deep; otherwise, they'll need replacing.
  • With V brakes, also check both brake cables for signs of wear or fraying. Start at the brake levers on the handlebars. Follow the cables along the top tube, then check the other end of both cables where they meet the brake calipers. If you find any signs of wear or fraying in your brake cables, they will need replacing.

11.     Check the headset. Stand beside your bike, and holding the headset with your left hand, apply the front brake with your right hand and rock the bike back and forth. Make sure you cannot feel any slack or hear any knocking in the headset. If you can, your headset will need adjusting.

12.     Lubricate the drive system. Place some rags over the rear wheel rims underneath the derailleur, to catch any oil drips.

  • Rotate the pedal anticlockwise to move the chain around. Holding the spray lubricant vertically, spray the chain for a few seconds as it passes over the rear gear cogs.
  • Moving the chain with the pedal, spray the teeth on the inside of the chain ring near the cranks. Rotate the pedal again and finally, lube the outside of the chain ring in the same way.

13.     Check the lights. Now reattach the lights and any other accessories you took off. Turn the front light on, making sure the light is bright, then do the same check with the back light.


Tuesday, January 6, 2009

automakers now producing their own bikes..

SUBARU


BMW



LAND ROVER




MERCEDES BENZ


PORSCHE
CADILLAC


JEEP

HUMMER

Monday, January 5, 2009

amazing biking videos!

crazy mountail bike trail! watch this!



amazing bmx rider! watch this!

bike brake systems..

Brake systems are used to slow down or stop the motion of a bike. There are mainly five types of brake systems: rim brakes, disc brakes, drum brakes, coaster brikes and spoon brakes. However, the commonly used today are the rim brakes and the disc brakes. 

In rim brakes, the braking force is applied through the brake lever by squeezing it. This causes the friction pads to contact the rim of the rotating wheel, thus slowing it or stopping the bike. Pictures below are among the many sub-types of rim brakes.  











In disc brakes, there is a metal disc attached to the wheel hub that rotates with the wheel. Callipers are attached to the frame or fork along with pads that squeeze together on the disc. There are two types of disc brake: mechanical and hydraulic. Mechanical disc brakes are almost always cheaper, but have less modulation, and may accumulate dirt in the cable lines since the cable is usually open to the outside. On the other hand, hydraulic disc brakes use fluid from a reservoir, pushed through a hose, to actuate the pistons in the disc calliper, that actuate the pads. The first picture below is a mechanical disc brake and the second one is a hydraulic disc brake. 







- wikipedia