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Ochoa0042
Posted on Monday, December 15, 2008 - 11:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

OK, a light bulb flicked ON in the noggin.... if the bike now has the muffler underneith the engine instead of it flailing high with the under seat exhaust. to place the muffler under the engine, you have to raise the engine up in the chassie to make up for the space for the muffler.... wouldnt raising the engine up higher to fit the exhaust underneith be counter intuitive???
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Bikerjim99
Posted on Monday, December 15, 2008 - 11:24 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

My first thoughts are that the muffler and shock, which have considerable weight, more than offset the aluminum engine being raised up. I suspect that there may be other considerations regarding engine mounting, swingarm placement, etc.
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Nillaice
Posted on Monday, December 15, 2008 - 11:30 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

i dunno how the XB was designed form the get-go , but only if the motor was raised to accommodate the fit. it makes sense when i look at a suzuki sv
http://www.bikez.com/pictures/suzuki/2005/21384_0_ 1_2_sv%20650%20s_Image%20credits%20-%20Suzuki.jpg

all that wasted space right behind the front wheel where you want as much mass to be. tisk, tisk...
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2008xb12scg
Posted on Monday, December 15, 2008 - 11:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Isn't the point of mass centralization to put all the wieght together, not necesarrily lower?
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Anonymous
Posted on Monday, December 15, 2008 - 11:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Basically the engine in the XB is set to where it clears the ground at a 55 degree lean angle. The room for the muffler was what was left over. So, in short, if you lowered the motor the clutch cover would drag on the ground in left hand corners when you ride really fast.
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Preybird1
Posted on Tuesday, December 16, 2008 - 12:04 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Yes 2008xbscg you are correct see below
http://www.buell.com/en_us/technology/design-philo sophy/
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Froggy
Posted on Tuesday, December 16, 2008 - 12:09 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Hahah Ochoa has lots of experience with dragging the clutch cover! : D

Time to look at getting a Uly! ; )
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New12r
Posted on Tuesday, December 16, 2008 - 09:05 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

You can drag a Uly too...

55 deg. lean angle is bull, I call 60 deg.
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Wolfridgerider
Posted on Tuesday, December 16, 2008 - 09:31 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

HA HA HAAAA!! I call 61.... 75.. 90... 110... 180.... 210... 270... 310.... 360...

RUN AWAY!!!!



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Midknyte
Posted on Tuesday, December 16, 2008 - 10:08 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Even *if* the engine were raised a little to accommodate the muffler, remember -
where other bikes have their gas tank, we have our airbox, and air weighs how much?
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Nukeblue
Posted on Tuesday, December 16, 2008 - 11:10 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

depends on the altitude...
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Hootowl
Posted on Tuesday, December 16, 2008 - 11:14 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

air doesn't weigh anything. It has mass, but air submerged in air is neutrally bouyant, and therefore weighs nothing.
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Wolfridgerider
Posted on Tuesday, December 16, 2008 - 11:17 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

all air is not equal....
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Nukeblue
Posted on Tuesday, December 16, 2008 - 12:58 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

my air's faster than your air!
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Brinnutz
Posted on Tuesday, December 16, 2008 - 12:58 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

my air is better.

(Message edited by brinnutz on December 16, 2008)
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Swordsman
Posted on Tuesday, December 16, 2008 - 01:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I think "mass centralization" isn't necessarily "lower center of gravity". Sounds like you may be confusing the two. A sledgehammer is mass-centralized, but I don't think anyone would say it had a low center of gravity unless you stood it on its head.

~SM
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Wolfridgerider
Posted on Tuesday, December 16, 2008 - 02:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

1st 521 Shawn Strawser 12:49.826
2nd 777 Mark Gainer 12:50.033 diff. 0.207
3rd 32n Bill Smith 13:28.267 diff. 38.441


Your air is only .207 seconds faster than mine..... LOL
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Pkforbes87
Posted on Tuesday, December 16, 2008 - 02:30 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

If you get the weight too low the bike will be very stable but turn in will be a chore. The new ninja 6r frame specifically raises the engine placement to increase "flickability".
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M1combat
Posted on Tuesday, December 16, 2008 - 04:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Yeah a low CG isn't beneficial in and of itself...

A cg that has the "right" height is beneficial : ).


You're also thinking in the wrong direction.


What happens when the rear/front of the bike hits a bump? The rear/front raises. THAT's where the benefit of the underslung exhaust and magnesium fairing bracket come into play : ). They allow the suspension to work better.
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Ochoa0042
Posted on Tuesday, December 16, 2008 - 09:15 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

have y'all seen the buell book about the theory of mass cen. ???
the diagram showed this:
a man holding two dumbells with his arms straight out, try to twist your body. its hard to do it
Now hold the weight clost to your body and twist, its much easier

relating that diagram to the bike, the only way it can relate is to the bike turning/leaning, realting that to a bike doesnt have to do with the other directional-plane stated above. it only applies to leaning.... ya following me here???

i also remember reading in that booklet that mass-cen. makes the bike flickable and whatknot, so i believe there's a flaw in this story
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Lemonchili_x1
Posted on Tuesday, December 16, 2008 - 09:39 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

"What happens when the rear/front of the bike hits a bump? The rear/front raises. THAT's where the benefit of the underslung exhaust and magnesium fairing bracket come into play . They allow the suspension to work better."

I'd never thought about it like that before. Centralising mass would effect all three axis - lean, pitch (for/aft) and yaw (left/right). If I remember my dynamics class from many years ago, this would reduce moment of inertia in all three axis requiring less energy to flick or turn the bike, and would be easier on the suspension as M1 said. (I might be using the wrong terms, that class was a long time ago!)

With c-of-g, Honda had a GP bike (I can't remember which one... maybe the first NR500?) in the eighties with exhaust over the top and the fuel tank underneath the engine and the c-of-g was *very* low and from what I remember the bike was very hard to ride, very unstable.
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Pkforbes87
Posted on Tuesday, December 16, 2008 - 09:59 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

"I remember the bike was very hard to ride, very unstable."

In my opinion it's all just a give and take.

In order to gain stability, an amount of agility has to be sacrificed. From the small amount of time I've spent on jap "crotch rockets" it seems to me that in well-trained hands, they have the potential to be a lot more nimble than any Buell I've ridden. BUT they feel twitchy, nervous, unstable. I guess that's all part of the difference between riding a race bike adapted to the street, and a street bike adapted to the track.
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Nukeblue
Posted on Wednesday, December 17, 2008 - 10:12 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

but still faster!.... for now : ) hey where's the mid-ohio stats?

(Message edited by nukeblue on December 17, 2008)
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Etennuly
Posted on Wednesday, December 17, 2008 - 10:23 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Mark, before you started your racing career I saw you test that 100 deg. lean angle from too close up!

From my experience the left peg will snap off at about 65 deg. and the tires will still have grip! .........Amazing!
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