[Engine inovations ??? !!!] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

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Engine inovations ??? !!!
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Posted by: velocityatv

What I think will be the grad finale will be if they use a reverse cylinder head. Like on the Cannondale.

Also I wonder if they'll adopt BMW's clutch idea. On the new 450 BMW dirt bikes the clutch is directly mounted to the crank shaft. No counter sprockets. Equaling less weight and a shorter engine design. That way they can place the motor more forwards or backwards depending on weight distribution.

I think power will fine. If it truely is lighter than the rest, less HP wont matter that much. Hell, my 250R right now would go tons faster if I shaved a few pounds off of my fat butt.

Posted by: ThePhantomRider

Well from the pictures I have seen online and looking at the blacked out parts on the web, it looks like it will not be a rear combustion motor like Cannondale. The airbox is in the underseat position and in the blacked out parts where you can spin the bike around to look at what is released, you can see the header exiting the front.

Doesn't look like they adapted the pivot drive like BMW though.

TPR

Posted by: terko440

Your right about the fat but part. ahaha

Posted by: velocityatv

Thanks..............JERKO440

I guess it's better to be a smart @$$ than a dumb @$$

Posted by: rpyfz450

quote:
Originally posted by ThePhantomRider
Doesn't look like they adapted the pivot drive like BMW though.

Is this where the engine's sprocket is concentric with the swingarm pivot?

Posted by: 54warrior

quote:
Originally posted by rpyfz450
Is this where the engine's sprocket is concentric with the swingarm pivot?

Yes.

Posted by: OutlawBill

quote:
Originally posted by ThePhantomRider
Well from the pictures I have seen online and looking at the blacked out parts on the web, it looks like it will not be a rear combustion motor like Cannondale. The airbox is in the underseat position and in the blacked out parts where you can spin the bike around to look at what is released, you can see the header exiting the front.

Doesn't look like they adapted the pivot drive like BMW though.

TPR

look like it would be hard to change the front sprocket

http://www.motoaus.com/images/stories/storyimages/bmw/bmw_450_sprocket.jpg

Posted by: rpyfz450

I'm surprised BMW did that on a modern machine. That design transmits engine torque to the rear suspension. Avoiding this is the reason why all manufacturers place the sprocket axle lower in the chassis than the swing arm pivot.

Posted by: motox450

quote:
Originally posted by rpyfz450
I'm surprised BMW did that on a modern machine. That design transmits engine torque to the rear suspension. Avoiding this is the reason why all manufacturers place the sprocket axle lower in the chassis than the swing arm pivot.

Actually if you read the suspension theory threads and talk to some respectable tuners they will all tell you the exact oposite. Keeping the sprocket in line with the suspension motion removes all the chain torque from the suspension. The chain and drive now works on one similar curve with no spikes. On bikes now there is a spike point where the chain is actually tighter in one spot than others. This "spike" in the motion curve puts added pressure on the suspension. Other Manufacturers haven't used it do to the isses of removing and changing the countershaft sprocket. BMW fixed that by making the counter sprocket shaft hollow and the axle runs through it. There is a great deal of good information out on the design.

Posted by: 54warrior

quote:
Originally posted by motox450
Actually if you read the suspension theory threads and talk to some respectable tuners they will all tell you the exact oposite. Keeping the sprocket in line with the suspension motion removes all the chain torque from the suspension. The chain and drive now works on one similar curve with no spikes. On bikes now there is a spike point where the chain is actually tighter in one spot than others. This "spike" in the motion curve puts added pressure on the suspension. Other Manufacturers haven't used it do to the isses of removing and changing the countershaft sprocket. BMW fixed that by running the counter sproket is hollow and the axle runs through it. There is a great deal of good information out on the design.

I have to totallly.....

agreee with that. This has been a problem that has been known for years and BMW is the first (that I'm aware of) to go forward with a design such as this to correct it.

Posted by: rpyfz450

quote:
Originally posted by 54warrior
This has been a problem that has been known for years and BMW is the first (that I'm aware of) to go forward with a design such as this to correct it.

Polaris ATVs have had this design for years on their older ATVs. The main purpose is to eliminate a change in chain slack as the suspension rebounds. IF chain slack is the only issue, that's a problem thousands of motorcycle designs have happily lived with for decades.

Someone please post a URL to discusssions of the "chain spike" that was mentioned above.

Posted by: motox450

quote:
Originally posted by rpyfz450
Polaris ATVs have had this design for years on their older ATVs. The main purpose is to eliminate a change in chain slack as the suspension rebounds. IF chain slack is the only issue, that's a problem thousands of motorcycle designs have happily lived with for decades.

Someone please post a URL to discusssions of the "chain spike" that was mentioned above.

Here is a coupr links to some of the many sites that have information on this bike and the suspension design. I post more as I find them. There is a small section that speaks of the benifits of using the design as BMW has.
http://www.trucktrend.com/features/...petition_enduro

another
http://www.autotrader.co.uk/EDITORIAL/33723.html