ZX25R ANNOUNCED!!!!

[serialk11r]

Uh wait, how are emissions standards pushing compression ratios down? CBR-1000RR is at 13:1. NOx aftertreatment is mandatory, not an option.

I did forget the earlier bikes were carbed and have no cats, so that's one less handicap to make up for the poor fueling control. Still, if the ZX6R is making 200 hp/L, I was hoping for the same from the ZX25R. I guess it's hard to win against friction.

I would think that gear driven camshafts are actually more likely because the stroke is short. It probably has around 35mm stroke, 75mm of connecting rod, so it's around 115mm to the valves from the crank, which I would think you can span with a single gear.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

I would think that gear driven camshafts are actually more likely because the stroke is short. It probably has around 35mm stroke, 75mm of connecting rod, so it's around 115mm to the valves from the crank, which I would think you can span with a single gear.

Considering that even Toyota 1HZ and 1HD engines which are considerably larger had only 3 gears for the valvetrain timing (OHC), it makes sense.

[Daschicken]

Originally Posted by serialk11r

Uh wait, how are emissions standards pushing compression ratios down? CBR-1000RR is at 13:1. NOx aftertreatment is mandatory, not an option.

I did forget the earlier bikes were carbed and have no cats, so that's one less handicap to make up for the poor fueling control. Still, if the ZX6R is making 200 hp/L, I was hoping for the same from the ZX25R. I guess it's hard to win against friction.

I would think that gear driven camshafts are actually more likely because the stroke is short. It probably has around 35mm stroke, 75mm of connecting rod, so it's around 115mm to the valves from the crank, which I would think you can span with a single gear.

Well, I suppose they could make it work with high compression, but I would expect a much higher HP number with higher compression. The top dollar bikes can get high compression. The CBR600 is sitting around 12.2:1. So the development goes where the money is.

Gear driven cams sound awesome, and are Uber reliable, but cancels any thought of head milling. So they are good and bad. I wouldn’t really mind either way, slight preference to gear driven cause I really doubt I would be tearing the engine down any time soon.

[roosterk0031]

I wasn't aware of any gear driven OHC bikes except for VFR. And I think that only happened because they had some problems with how long the timing chain was for a V4. That stared in late 80's with the VFR750 later 800. I had a 83 V45 Interceptor a short time. Does you 400 have gear drive?

[Daschicken]

Originally Posted by roosterk0031

I wasn't aware of any gear driven OHC bikes except for VFR. And I think that only happened because they had some problems with how long the timing chain was for a V4. That stared in late 80's with the VFR750 later 800. I had a 83 V45 Interceptor a short time. Does you 400 have gear drive?

Yes, both the 400 and my 250 have gear driven cams.

Some other bikes I know have gear driven cams:
2000-2006 RVT1000
1986-1997 VFR750
1998-2001 VFR800
1986-1996 CBR250 various models
1989-1990 CB-1
1986-1996 VFR/RVF 400 various models

[cRiPpLe_rOoStEr]

Originally Posted by Daschicken

1986-1996 CBR250 various models

I was only aware of these and the Hornet 250 fitted with the same engine.

[Daschicken]

Well, its no 250, but a 400cc version of this bike was announced for the U.S. market!





https://www.kawasaki.com/en-us/motor...LIST-_-VEHICLE



I'm a big fan of putting your money where your mouth is. I figured an inline 4 250cc would have to be in the $8-10K range to make sense, and this larger 400 is in that range. Already got a deposit down on one for when it comes in. Looks to be around 80 horsepower, 16,000 RPM, 415 pound curb weight.

I was wondering how they were going to handle component specs, I figured when I was thinking up the potential of one coming to the U.S. it would either have to be a stripped down basic model with cheap components to bring the MSRP down, or a fully equipped top of the line model with adjustable everything and race spec components to entice the trackday bros. Looks like they bridged the gap, fully adjustable rear suspension, but only preload adjustable front. Adjustable levers, up/down quickshifter, dual front discs with radial mount calipers.

Exhaust system is set up in a way that makes it easy to install a slip on exhaust and keep the catalytic converters, which is awesome. Although, if its anything like the Z900 I rode recently, the intake noise is honestly intoxicating enough that I may just keep the stock exhaust on it. I'm more of a fan of quieter exhausts nowadays.

https://www.msn.com/en-us/autos/enth...us/ar-AA16Zvml

Glad to see some positive press of it coming out right away. Whenever one of these high spec small displacement bikes is discussed, there is always someone who comes in and says you can get more bike for less money with something bigger. Of course you can, go on craigslist and pick up an early 2000's literbike if you want power on a budget.

[JSH]

I was pretty shocked to see the ZX-4RR is coming to the USA. It will be a market failure that disappears in a few years so buy one now if you want one.

The problem is that the 400cc bike is $9,699 while the 636cc ZX-6R starts at $10,699 and the full out ZX-6R KRT ABS is only $11,799. Most buyer will take the extra CC's and HP for $1,000 to $2,100 more.

However, the ZX-4RR would make a fantastic track day tool. Plenty of HP for the application and you can actually use those 16,000 RPM. This bike will likely hit 65 mph in first gear and topping out 2nd or 3rd gear will be go-to-jail speeds. (The 636 has 1,000 less RPM and hits 120 mph in 3rd)

[Daschicken]

Yeah I don't see it sticking around for more than probably 3 years, but I still think they will make money off of it. Hopefully first isn't quite that tall, but we'll see. There has been more commotion in the last few years about these tiny four cylinders, so it may do better than you would expect.

[redpoint5]

I was just going to comment that with those specs, it certainly isn't detuned to get good MPG. As Jason pointed out, the 600cc bikes are all higher performing, lighter weight, for not much more money.

If I were to purchase another sportbike, it would be a liter.