Joe Gibbs Racing Bikes


14 replies to this topic
  • todds924

Posted April 09, 2008 - 08:46 PM

#1

I had a close up look of the Joe Gibbs Race team Bikes and noticed something very interesting! I noticed that the front motor mount plates have been machined through in the centers and also the upper mounts have been machined out in the middles and you can "see through" them....instead of being solid mounts. You can see what i'm talking about on the Joe Gibbs web site. I think they are doing this to get some flex into the chassis kinda like Kawi did with the 08 450's motor mounts. Interesting! Wouldn't be hard to do if you had a Mill or knew a machinist. Both Josh Hansen and Josh Summey's bikes are like this.

  • rickallen124

Posted April 09, 2008 - 08:57 PM

#2

Yeah one of the mags or websites had pictures of the motor mounts. Gibbs can build anything they want and it will be interesting to see what things they fabricate themselves. I'm glad they have Grayck on the team now, no one more deserving.

  • Ga426owner

Posted April 10, 2008 - 04:31 AM

#3

Anyone know real reason Hanson was released for JGR?

  • rickallen124

Posted April 10, 2008 - 05:20 AM

#4

Only Gibbbs and Hansen know the real reason as everything they have said has been politicaly correct. I would imagine that it came down to the fact that he wasn't willing to put forth the effort that Gibbs expected of him- he wasn't even making the main. He may have been having a negative effect on the team. All I'm sure of is that he wasted a great opportunity with that team.

  • USED YZ426F

Posted April 10, 2008 - 05:42 AM

#5

I noticed that the front motor mount plates have been machined through in the centers and also the upper mounts have been machined out in the middles and you can "see through" them....instead of being solid mounts.
*SNIP*
I think they are doing this to get some flex into the chassis kinda like Kawi did with the 08 450's motor mounts.


Why would you want flex in the chassis? I would think that flex would potentially cause the bike to be unstable at speed or over rough terrain.

I can see milling out the centers to reduce weight. Even though they only got rid of a few grams doing that mod, they can do a lot of other similar mods to shed a few grams here and there (drilled axles, titanium bolts, etc). Pretty soon you are looking at shedding a couple of pounds, and I can see that being beneficial on the track.

  • MX926

Posted April 10, 2008 - 05:43 AM

#6

There is a podcast on racerx with Jeremy Albrecht that hints toward the reason.

  • IDAHOBALLER

Posted April 10, 2008 - 09:14 AM

#7

[quote name='USED YZ426F']Why would you want flex in the chassis? I would think that flex would potentially cause the bike to be unstable at speed or over rough terrain.
[QUOTE]

Having the proper amount of flex in the chassis is absolutly critical to having a good handling bike. When you are turning and the bike is leaned over the chassis flex has to be there to act as suspension since the swingarm and forks operate on a plane perpendicular to the handle bars but the ground under the bike is not always perpendicular to the bike which is when the suspension can work to its best potential. I am not syaing that the suspension doesnt do anything while turning, I am saying that without the flex the bikes become resistant to leaing into the corner and will want to stand up on you at times. Which is why every year you hear about them feeding more flex into a certain area of the motorcycle to create a cood balance of agility as well as retaining stablity. If the chassis is too flexy the bike will have a hard time holding lines around corners because there is less I guess you could say force trying to hold the tires down on the ground.

Flexy frames usually feel much more nimble to an extent because the chassis doesnt have to fight its self as much because it can bend a little here and there, which has a lot to do with why the 06 and newer YZFs feel like they weigh less than they actually do while riding it. Now, the flex is not always a good thing, and in environments like the sand dunes a stiffer frame will actually be a better choice because the sand has dramatically less influence on the bike because it has soo much give to it and doesnt really pack tighter under the tires much, and you dont want the bike to wander around and pick and follow ruts and such because the wheels are flexing slightly out of their regular plane. you want the chassis to be resiliant enough that the wheels do what they are told becuase the bike in sand is going to wander some anyways without the flex in sand.

IMO on dirtbikes the flex is very important to having a great handling bike but with the long travel suspension it can be greatly affected by the suspension setup, but on say a crotch rocket the frame flex is absolutly critical to how the bike handles since they have dramatically less suspension travel that can hide chassis imperfections. If you were to ride say a 2000 R1 back to back with an 2008 R1 on a race track you would see how much more resistant the bike is to leaning into the turn as well as how much less chassis communication and feedback that you feel when riding compared to the newer R1. Most of the differences are attributed to have the right balance of flex and stiffness in certain areas since the outright dimensions and weights of the two machines are very close to one another.


Just my opinion though...

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  • hillclimbguy

Posted April 10, 2008 - 05:19 PM

#8

Its too bad about little hanny. His dad made a name for himself and rode hard and never gave up. These young riders now have it too easy and focus on the wrong things instead of racing. I think JG racing is a top notch outfit and they give their riders everything they need.
I miss the 2 strokes!

  • MX926

Posted April 11, 2008 - 09:29 AM

#9

Everyone misses the two-strokes. More fun to ride, sound better, and way cheaper to repair.

-Maybe one day they will make a return.......

  • grayracer513

Posted April 11, 2008 - 12:24 PM

#10

Everyone misses the two-strokes.

Not everyone.

  • IDAHOBALLER

Posted April 11, 2008 - 01:19 PM

#11

The two strokes are not gone, they just arent on top of the performance curve anymore when compared to the 450's on an MX track. I still see plenty of smokers all the time. In fact there is an 06 YZ250 sittin in my shop right now keepin my 450 company.:thumbsup:

I prefer my 450 for most conditions, but the 250 smoker sure is hard to beat in the tight twisty stuff...

  • never59

Posted April 11, 2008 - 01:20 PM

#12

Yeah one of the mags or websites had pictures of the motor mounts. Gibbs can build anything they want and it will be interesting to see what things they fabricate themselves. I'm glad they have Grayck on the team now, no one more deserving.



+1 on that!! I am amazed that anyone is willing to sign josh hansen

  • Wyatt

Posted April 11, 2008 - 05:21 PM

#13

If Hansen doesnt get back out there and finish in the top twenty, then it will screw Dungey.

He will finish in the top 20 and then be bumped to the big bike class before he wanted to be there.

  • hillclimbguy

Posted April 11, 2008 - 09:12 PM

#14

I will always have a two stroke as long as they re available. Gotta have one of each. 2 and 4

  • almostinvincible119

Posted April 11, 2008 - 09:16 PM

#15

i love how this thread was actually about the engine mounts (which i would love to see a picture of) HINT HINT

but when one guy says he misses the two strokes. all everyone starts to talk about are the oil burnin, last place ridin pieces of crap. i love em to play ride with.

but if you race. and if you race seriously.

they are WORTHLESS





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