Review of 2010 Yamaha Dirt Bikes.Checkout Used Yamaha Dirt Bikes For Sale: Motox1160.adpost.com
2010 Yamaha YZ450F:
No one expected 2010 to provide redesigned Yamaha motocross bikes in both the 450 and 250F Classes! All new for 2010 is a completely redesigned YZ450F featuring a new Fuel-Injected Motor, and completely new Bilateral Frame design. The new liquid-cooled DOHC 4-stroke, 4-valve engine is designed to provide improved power delivery while providing better centralization of mass. Bore and stroke is 97.0 x 60.8mm, which is 2mm larger in bore and 2.6mm shorter in stroke compared to the 2009 Yamaha dirt bikes model. The shortened stroke reduces the height of the engine for better mass centralization. The compression ratio was also increased to 12.5:1 from 12.3:1. The Yamaha dirt bike engineers took the rearward-slanting engine concept to a whole new level by offsetting the cylinder 12mm from the crankshaft. The result is a massive reduction in friction due to the more efficient design approach of having the connecting rod vertically positioned at the precise moment of greatest combustion pressure. New for 2010 is the incorporation of a Fuel-Injection system which continuously monitors changes in running conditions. This is accomplished by gathering information from intake pressure, intake air temperature, air pressure, crankshaft RPM, throttle position, and coolant temperature sensors. Based on this data the on-board electronic control unit (ECU) calculates the precise amount of fuel volume to be delivered. The fuel is feed through a 44mm Keihin throttle body from the front of the engine through a motocross specific 12-hole injector. With the inclusion of Fuel-Injection, the Yamaha dirt bikes incorporate a large capacity Alternating Current Magneto to eliminate the need for a battery (thus reducing overall weight). Unlike other Fuel-Injection systems Yamaha’s FI is completely tuneable by the user using an optional
Yamaha GYTR Power Tuner accessory.
Similar to the 2010 YZ250F, the Bilateral Frame was developed using new structural analysis methods. The frame itself consists of 16 components made from four different aluminum processes using revolutionary semi solid die-casting techniques. This approach allows complex shapes to be constructed stronger with just the right amount of controlled flex in critical areas. Thanks to the new technology the frame is more symmetrical allowing for a better overall chassis feel, while enhancing the frames ability to absorb/withstand forces and impacts with better balance and more consistency. To accommodate the new frame design the rear suspension has been positioned in line with the machines central axis. The position of the rear shock itself has been moved approximately 30mm lower. Additional changes to the KYB shock absorber include an increased cylinder diameter from 46mm to 50mm for greater capacity. These shock revisions have created a new damping force curve which provides improvements to rider control and feel. In tune with the new frame and shock mount is a brand new swing-arm design that provides even greater cornering performance compared to the 2009 model. The thickness of the rear axle clamp has been increased for greater rigidity while providing good longitudinal flexibility and high lateral/torsional rigidity. In conjunction with the upgrades to the frame, the front fork triple clamp offset has been reduced from 25mm to 22mm. Caster, trail and other chassis dimensions have been optimized in relation to each other to help achieve a higher-level of handling performance. The new triple clamps also feature the same four-way adjustable handlebar mount design as found on the 2010 YZ250F. Additionally, an all new seat/under seat fuel tank has been introduced for 2010 which provides greater centralized machine mass and a lower center of gravity (COG).
2010 also provides a complete redesign of the highly successful YZ250F Yamaha dirt bikes. This years YZ250F Yamaha Dirt Bikes feature an all new aluminum perimeter frame which is more rigid under a horizontal load & twisting, however provides the same stiffness under vertical loading conditions as the 2009 model. The head angle has been slightly increased to 27.5 degrees, and the trail increased to 120mm. In the engine department Yamaha redesigned the air intake boot to improve overall throttle response. This year's Keihin carburetor features a built-in velocity stack and improvements to the accelerator pump cam shape for quicker fuel delivery. The intake cam lift has been increased to 7.7mm. Valve spring loads have been reduced, the spring retainers have been changed to aluminum, and a chromium nitride surface treatment has been added to the valve stems. Additionally the exhaust has been redesigned to both increase velocity and improve low-end power. Return From Yamaha Dirt Bikes to Home Page.
Yahoo! Personals 7 Day FREE Trial offer Free Domain, Unlimited Disk Space, Unlimited Data Transfer and 25% off with Yahoo! Web Hosting Buy multiple job ads at Yahoo! HotJobs and save up to 65% Prospective patients are searching for physicians.Help them find you with Yahoo! Search Marketing. Yahoo! Sponsored Search connects businesses and customers online. Sign up and get a $25 credit.
|
