When i went to the autoexpo 2008 i visted the yamaha section there i saw this bike looking pretty much similar to the R1 thats R15. I just loved the way the R15 looked. and the hype was almost too much to resist for me. i was so very tempted that i even thought of selling off my pulsar 220 and booking R15, it was just too tempted. and the way yamaha designed their website for r15 was amazing with countdown timer and all. finally the day when the bike was launched, i literally hurried to the showroom to get my hands on the r15.
the moment i entered the showroom, there was a blue R15 standing infront of me, or so i thought. at first glance, believe me, i thought it was, in all probability, a scaled down model of R15 and not the real bike. the reason…………. the bike is just too small. i mean just too small. it looks much like a circus bike which dwarfs ride.
I was literally heart broken. i was expecting a huge monster looking bike but what i got is a monster-ling.Now We Get Into Some Technical Info
Engine
YZF-R15 is equipped with this all-aluminum cylinder called the DiASil Cylinder and a forged piston, the same type of piston used in YAMAHA’s supersport bikes. The fact that both the piston and cylinder of YZF-R15 are all-aluminum ensures excellent heat dissipation, eliminates heat-induced engine power loss, and helps improve fuel efficiency. The DiASil Cylinder is given a special surface treatment to prevent oil evaporation from the cylinder’s surface and improve oil consumption. The cylinder also has excellent hardness and is considerably resistant to wear compared to conventional iron sleeves.
Additionally, the piston is made in a forging process, the optimum way of achieving lightweight designs.The reciprocating mass with the forged piston is approximately 20% less ( according to Yamaha test ) than with an engine of the same displacement fitted with a conventional cast aluminum piston. Resulting in an invigorating feeling when revving up. Conventional pistons are typically made in a casting process where molten aluminum is cast in a mold. YAMAHA developed its proprietary “controlled forging technology” in 1997, which enables mass production of forged aluminum pistons. These pistons have been used in sport models such as the R series. The same manufacturing process was used to develop YZF-R15. Forged pistons retain the excellent strength of aluminum alloys because the metallurgic matrix of aluminum is not affected during the fabrication process. Therefore, the piston can be made lighter and thinner.
Chassis
YZF-R15 is equipped with a linked type monocross suspension that delivers a comfortable ride and a cushioning performance that is less prone to bottoming out. In particular, it reduces annoying “sinking” when riding tandem. The linked monocross suspension consists of a link mechanism sandwiched between the rear arm and cushion unit to create changes in the lever ratio based on the lever effect. When the shock absorber is almost fully extended, the lever ratio is high and therefore the spring is soft, and the damper works softly as well.
As the shock absorber strokes in, the lever ratio gradually decreases and the spring rate increases. Eventually, when it is nearly fully stroked in, the lever ratio becomes small and the spring becomes hard and strong. The damper also becomes hard. By making changes to the lever ratio in this way, we were able to achieve soft riding comfort as well as excellent damping under intense load conditions. The optimization of the frame and rear arm rigidity of the Deltabox Frame combined with the effects of the linked type monocross suspension achieve good riding comfort, agile handling, and turnability, hardly ever causing bottoming out.
Fuel Efficiency
In order to maximize the efficiency of the fuel injector, which injects the optimum amount of fuel for different amounts of intake air, YZF-R15 is equipped with a large 3-liter air cleaner. The duct area of the intake duct was designed optimally to optimize the flow of intake air. Additionally, the use of a 4-valve combustion chamber (a combustion chamber with 2 intake and exhaust valves each) has allowed designers to layout the spark plug at the center of the combustion chamber for better flame propagation. This also increases the total valve area relative to the 2-valve chambers for improved intake/exhaust efficiency (volumetric efficiency). YZF-R15 is fitted with a hemispherical 4-valve combustion chamber, a configuration that allows intake and exhaust valves to be laid out in the smallest size possible.
Following are some performance figures of Yamaha R15:
1) 0-60km/h : 3.0 sec
2) 0-100km/h : 9.0 sec
3) Top speed : 145km/h
4) Fuel economy : Around 35-45kmpl
Summary
On features front this bikes is really awesome. An Indian bike enthusiast this one is really very good. But the main problem with this heavily powered bike is that its small and for those who are tall this is not meant for them. But if you just want a high performance bike with decent fuel efficiency then you should go for this. And mind you this ones gonna carry a price tag of about 1 lakh which is really very high for 150cc bike but then again its a yamaha with best acceleration. But before going for this you must consider Karizma and Pulsar 220.
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