Sunday, July 27, 2014

Key Factors to refer before Bike Modification

FITTING THE FREE FLOW AIR-FILTER
Fitting an after market free flow air-filter increase the percetnage of air in the air-fuel mixture. Thus, an engine tends to run lean and gets hot quickly therby affecting the overall perfromance. In order to compensate for the added air flow, you have to supply more fuel as well. This can be done by retuning the carburetor but in most cases requires up jetting it. Hence, it is vital that you reject the carburator.

INSTAL OVERSIZED PISTON
Increasing the bore won't help. You need to alter the size of the valves, and allow better engine breathing. Last but not the least, get all this done by a proffesional mechanic.

REPLACING REAR TYRE
It is now become a trend to customise regualr bikes with bigger rear tyre. Well it increases the stability of bike but the main factor in customising bigger tyre is, reduce in economy. And for regular bikes it may vary in the peroformance level too. Also, the stock tyres are quite lightweight and putting wider tyres will hamper the overall performance of the bike.

Well feel it will be better if you upgrade to a more powerful bike than doing heavy modifications to the regular bikes.

The new BEAST YAMAHA R25


The Yamaha R25 has been one of those bikes that has generated lot of interest from the word go itself. Yamaha has confirmed about its plan of launching the new 250cc bike in our market, So let’s take close a look at the Yamaha YZF-R25 and what it has on offer.

Let’s start with styling, one of the main reasons for the inquisitiveness about the R25 was its M1 inspired styling, the concept bike possessed. The Indian biker has a soft spot for a full-faired motorcycle and the R25 wouldn’t disappoint them on this front.

Yamaha R25 headlight shot
The R25 houses a 250cc, liquid-cooled, in-line, four-stroke, two-cylinder powerhouse that is mated to a six-speed gearbox. The eight-valve DOHC motor produces maximum power of 35.5bhp at 12000rpm while peak torque of 2.25kgm is made at 10000 revs.
The R25's 166 kg kerb weight is supported by telescopic front forks and a monoshock rear suspension. Stopping power is managed by a single front and rear disc brake, which are mounted onto smart looking ten-spoke alloys finished in black. 
The R25 is available in three colour options – blue, black and red.

YZF-R15 Technology that defines its class

THE HEART AND SOUL OF TRUE BIKING. Yamaha intergrated some technologies in the R15 which comes directly from their international racing bike the YZF-R1. R15's technologies diffrentiate with other indian bikes.

The concept of YZF-R15 was to desgin a new 150cc supersport model. Yamaha's objective was to create a well defined combination of an enjoyable ride on winding roads, running performance and comfort in riding , light weight, agile handling in crowded traffic and styling integrated from YZF-R series. Yamaha engineers made full use of expertise and technologies gained from long years of product development and race activities in desigining the R15. For their ultimate vision, they chose the optimum methods and technologies. The bike specifications those reviewed led to was a liquid-cooling engine with the Yamaha DiASil cylinder, a forged piston, a four-valve configuration, fuel injection and six-speed transmission. For the chassis a Deltabox frame was chosen with a linked type monocross suspesion.

Yamaha R15 is powered with 150cc displacment engine with performance that can leave most of the higher engine capcity bikes of concept of the R15 is based on excellent performance in accelaration, braking and cornering. Undoubtedly, the R15 exceeded expectation when it launced. The R15 has disproved the myth which says that you need a hiher cc engine to build a more performance bike. Yamaha succeeded in making the YZF-R15 an ionic bike among the youth.

LIQUID-COOLED ENGINE
An engine gets very hot when running, but if it gets too hot it loses power. Therefore a coolong system is needed to maintain a stable power output. There are two types of cooling system that wraps the engine in a system of fluid passages called a 'water jacket' and circulates coolant through it in order to cool the engine.
The liquid-cooled system on the R15 ensures a stable power output under a variety of different use conditons. The primary benefits of the liquid-cooled engine are more stabkle performance in sustained high-speed running and while going uphill, etc. Another merit is that because the liquid-cooling system wraps the cylinder in a system of coolant fluid passages, the coolant absorbs mechanical noise of the piston and valves and also contributes to the reduction of vibration.          

FORGED PISTON
The forged piston has a characteristicfeature that reduces the reciprocating mass of the piston by approximately 20 percent. The aluminum forged piston is made by heating the aluminum alloy to a temperature lower than the melting point and pressing it into a mold. Because the aluminum is not actually melted, there is much less effect strength. Due to this inceased strength, the forged piston can be made thinner and lighter. This also means that the forged piston can be made thinner and lighter. This also means that the forged piston has a lower reciprocating mass when the engine is running.

FUEL INJECTION AND 4-VLAVE ENGINE
Apart from these technologies, the R15's power unit has many other high-spec features. Two of these are the fuel injection system and the four valve, hemispherical combustion chamber. Fuel injection is a double benefit feature that improves fuel economy and enviornmental perforamcne ath the same time. A four valve combution chamber has two intake and two exhaust vlaves.
Yet another performacne feature is the roller rokcer arm of the valve lift system. In the case of an SOHC engine, the lever called rocjer is used to transfer the revolution of the camshaft into the valve drive froce. There is a loss of power in such case, To reduce the loss samll bearing is used to  reduce the friction. This provides smoother valve operation that in turn leads to improved economy and more responsive engine feeling.

THE DELTABOX FRAME
The Delta frame is a 3 point of the upper and lower ends of the head pipe and the pivot assembly. The cross-section of the frame memeber connecting these 3 points is a box shape, thus combining to get the name Deltabox name. Thsi kind of frame makes it easy to create an ideal strength rigidity balance a standerd on race machines and supersport models and that same basic frame desgin technology has been applied to the frame of the YZF-R15.

DiASil CYLINDER
A liquid-cooling system adds more parts to the power unit than parts to the power unit than the an air-cooling system and brings with it increased machine weigth. But Yamaha has an answer to this problem. The company adopted a Yamaha exclusive all aluminum DiASil cylinder fro the cylinder to be cooled. This is the first time that such a technology has been used for a motorcycle marketed in India. The company explains that the DiASil cylinder improves cooling performance by 60% while reducing cylinder weight by 30%.