As per my knowledge the current R15's engine is already a bore out version of a 135cc mill & this is its max limit. I mean this same mill can't be bored out further to make 250cc for sure. Also it is a fat free bike & no further modification can be done to its chassis for accommodating a bigger engine.
Anyways, eagerly waiting for cbr150.......it would be very interesting to see how does it compares with the r15.

@amitmalve
I just gave the above analogy.It's not a claim that yamaha launches R25.
May i know first of all from which bike(in which country) did this 135cc mill come from.I thought that is an all new engine.Do you mean the mill came from R125?
I don't know how tight is the chassis for engine.
Hope yamaha will come up with r25 soon.
Yes eagerly waiting for cbr150 after pulsar.Nice competition around there.Customer has become the king in Indian motorcycle market too.

Yamaha R15's engine is not a bored out one. It is Yamaha vixion with 6 gears.
And , you think anyone can bore out 100cc more from a 150cc engine..?? I dont think so...

^^Yes you are right but at first place Yamaha Vixion's mill is only derived from yamaha T135. Obviously no where in the world a 150cc can be bored out to a 250cc. Sorry for the OT.

Friends, can Honda price their upcoming CBR150 below Rs 1 Lakh Mark???

Don't think so...on Delhi AutoExpo i talk with the Honda person; he says approx 1.10

Just saw a board at a nearby Honda showroom-Honda CBR15OR Coming soon

Bike will launch in April....i wish Honda start taking booking for bike before a launch...so that people interested can get without delay...

is the launch date confirmed?

Yes i agree that one can't bore a engine to 100cc more.Guys the above is just analogy.so most of you think r15 and cbr250 are aptly priced?

Actual date on confirmed...but surely in month of April 2012

Lol. First you say Yamaha will rebore 150 to 250. And then you say one cant bore 100cc more.
Make up ur mind for once?

As for the first highlighted post. Plonking a 250cc engine on a frame made especially for a 150cc is not easy.
Also it takes a lot of research and money to go back to the drawing board and plan everything from scratch to get a 250cc R series bike.

Just replacing the engine and strengthening the frame wont do anything. Even the transmission line will need to be altered.
And there is a whole lot of calculations that will need to be done regarding suspension/brakes/frame/tyres/ etc which will take atleast 5-6 months to achieve perfection.

Also fitting the Duke with a fairing will be of no use unless the fairing actually serves its purpose and has been designed for that specific bike. It takes research to design an efficient fairing and again that costs Money.

So its not just about plug and play here. Every component you see on these 1 lac + bikes actually go through a whole lot of R&D compared to everyday commuters!

Diasil cylinders and forged pistons dont come cheap. This is why the R15 is 1 lac +

Let me elaborate on what Nithesh said:
R15 can't be rebored to 250cc as it will require around 18mm increase in Bore, if you leave the stroke untouched. Existing cylinder is too thin for a 18mm increase in bore.

Even if we talk about a new engine cylinder & head, the Bore increase will definitely give it short stroke like characteristics, which means more & more revving. Most of its OTHER engine components (for example, valve springs) are not suited for even 11.5 krpm redlining. So, can't do that.

And if Yamaha changes its stroke too, then its already a new engine. Then same R&D costs, NVH testing, mileage optimization, etc, etc. So, depends on Yamaha whether they want to spend the money...

Chassis can match it though I think. Its very much rigid & a "racing line chooser" already. R15's chassis is one of the best I ever rode.

Btw there is a company that sells a fairing for the 690 duke, am assuming its only a matter of time before they make one for the 200

I think both these bikes are slightly Overpriced....Though i still feel Honda will give Competitive Price tag to its upcoming CBR150R