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Archive through February 22, 2011Mad_matt30 02-22-11  03:56 pm
         

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Rocketsprink
Posted on Thursday, February 24, 2011 - 05:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I road raced both and MUCH prefer the 12
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Ericz
Posted on Thursday, February 24, 2011 - 06:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

That's one thing I have never understood. If an XB9 engine "revs faster" than a XB12, then the XB9 should accelerate faster than a XB12 as long as they have the same gearing. But I have not experienced a stock XB9 that accelerates faster than a stock XB12. The XB9 has a lower primary ratio so it might just sound faster? Hmmm?
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D_adams
Posted on Thursday, February 24, 2011 - 07:23 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Lighter reciprocating mass? I would think that would allow the 9 to rev quicker.
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Glitch
Posted on Thursday, February 24, 2011 - 08:10 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

It is a much smoother engine.
I road raced both and MUCH prefer the 12
The power to weight ratio had nothing to do with it ; )
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Strato9r
Posted on Thursday, February 24, 2011 - 08:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

The 9 will seem to go through it's RPM range faster because it is geared lower. Though at a given engine speed, the 12 will produce more horsepower (actual work done), because of it's higher ratio primary drive, the complete amount of force exerted to the rear wheel is very similar, with the edge to the 12, and always at a lower engine RPM relative to rear wheel speed. What I think is cool is that each engine has it's own character, and because of that, the same machine can seem a lot different, depending whether it's a 9 or 12. I really like the 9 in a Firebolt, but I would absolutely love to have a Super TT, and the 12 engine would be one of the cool things about it. Having the engine making so much more low end power would be sweet, and I'd probably end up going to the 9 primary; I still have a thing for Big Block powered cars with short gears, and I think that a short geared TT would be freakin' sweet.
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Reepicheep
Posted on Thursday, February 24, 2011 - 08:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Eric, that isn't the case, because at a given RPM, the 12 is making more HP than the 9.

HP is what matters, and when people talk about "torque" what they really mean is usually "The HP versus RPM curve". So they say Buells have great torque, but what the mean is that Buells produce good horsepower at even low RPMS.

The 12 moreso than the 9.
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Jandj_davis
Posted on Thursday, February 24, 2011 - 09:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Reep -
HP is calculated using torque and RPM
HP = (TQ * RPM)/5252

So, HP really doesn't matter. Torque and RPM are what really matter. That's why a current literbike can make so much more HP with so little torque, it has more revs.
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Glitch
Posted on Thursday, February 24, 2011 - 09:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Actually it's all black magic
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Reepicheep
Posted on Friday, February 25, 2011 - 08:16 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

JandJ,

You are correct, and it would be relevant, if all motors had the same redline, and none had transmissions.

Transmissions multiply torque. So an engine that makes 1/2 the torque but can go 10x the RPMs is simply a faster bike. It will always be a quicker bike also, provided you get the gearing right and the operator can use a clutch aggressively.

Torque, taking into account the RPM that it can be maintained at, is Horsepower. Thats why these discussions should be about horsepower.

If torque was the main point, I could go infinitely fast just by continuing to change the gearing on my motorcycle.
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Glitch
Posted on Friday, February 25, 2011 - 08:38 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

In 2003, the XB9 had the largest torque to weight ratio of any other production street bike.
Certainly not the fastest street bike of 2003.
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D_adams
Posted on Friday, February 25, 2011 - 08:41 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Why not use an infinitely variable drive? It might be an interesting intellectual challenge to make it work, but if you could do it.... well, maybe not. Lack of gear changes might suck on a bike.

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Rotor
Posted on Saturday, February 26, 2011 - 12:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

infinitely variable drive?

this is working and on the road with Audi and his multitronic transmission

http://en.wikipedia.org/wiki/Multitronic
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Danxb9r
Posted on Sunday, February 27, 2011 - 06:59 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I prefer the 9 engine more. It revs higher. The 12 seems like a diesel engine lol
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Foximus
Posted on Wednesday, March 02, 2011 - 02:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Oh lets just face it. Eitherway an S1 is better.





...crybabies...
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B1bomber
Posted on Wednesday, March 02, 2011 - 03:08 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

God , I love those old Tubers ! They are a classic .
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Augustus74
Posted on Wednesday, March 02, 2011 - 11:09 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Hmmmmmm....what size motor does a tuber have though???
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Foximus
Posted on Wednesday, March 02, 2011 - 11:21 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

doesnt matter... 2000 awesomeC's its a better unit of measurement.
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Xoptimizedrsx
Posted on Thursday, March 03, 2011 - 04:56 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

another thing to watch out for is the companies using metric measurements when your use to sae.

there Tq numbers will look really good but if you put it to sae scale the drop a lot.
as in 87nm ~= 64 ft. lbs

big difference.

I am not seeing a rev speed difference in my 9 and 12 as free rev but the 12 will out pull the 9 getting to higher revs faster.
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