2010 YZ450F Attack position/suspention question

[Skotten]

Is it just me, or do you have to be further up on the bike for the attack position. I almost looped out at the track this weekend, on other jumps I noticed the front wheel was high. I have never ridden a 450 before I moved from a Crf250 to this bike. it could also be that I haven´t worked out the gearing yet. I lifted the bike on the stand and it was perfectly balanced, I got on it and tried to find the balance and found it is much further forward.

Has anyone else found they must be further forward on this bike than others??

[Scrubba]

yes a lot of times

[Skotten]

Would moving the bars to the forward mounting position help with this????

[hadameo]

If you are used to powering off a jump while riding a 250 you do not have to on a 450!It sounds like you are blipping the throttle at the top of a jump!

[Scrubba]

Is it just me, or do you have to be further up on the bike for the attack position. I almost looped out at the track this weekend, on other jumps I noticed the front wheel was high. I have never ridden a 450 before I moved from a Crf250 to this bike. it could also be that I haven´t worked out the gearing yet. I lifted the bike on the stand and it was perfectly balanced, I got on it and tried to find the balance and found it is much further forward.

Has anyone else found they must be further forward on this bike than others??

f/r weight bias on the 2010 yz is 50%-50%

other bikes are about 60%F-40%R

i think the KTM is opposite.

[NE14MX]

Where do you guys come up with this stuff. From the Dirt Rider shootout;

Weight: tank full

450 Total Front/Rear Bias

Honda CRF450R 237 121/116 51/49%

Kawasaki KX450F 250 125/125 50/50%

KTM 450 SX-F 251 124/127 49.4/50.6%

Yamaha YZ450F 248 127/127 50/50%

[Skotten]

I spoke to my friend about it today, he is geussing I am giving it too much power of the jump.. Weight, power, more less fuel in the tank. When I found the approximate balancing point on the bike, I found there is much more bike behind me than what there is on the CRF. I guess I have to exsperement some more next weekend, 5 long more days of work to go..... Thanks for all your input. If anyone else has some ideas, points of veiw or information it would be great to read.

[Scrubba]

I spoke to my friend about it today, he is geussing I am giving it too much power of the jump.. Weight, power, more less fuel in the tank. When I found the approximate balancing point on the bike, I found there is much more bike behind me than what there is on the CRF. I guess I have to exsperement some more next weekend, 5 long more days of work to go..... Thanks for all your input. If anyone else has some ideas, points of veiw or information it would be great to read.

same as i did. true, forks are too soft on crf so you gotta ride the rear more.

HOWEVER! perhaps riders are missing the theory of the FIELDMOUSE TECHNIQUE.

This technique states, that like the scampering fieldmouse, the only time the front legs need to touch the ground are in the turns. this can be seen on slow motion studies of the mouse. meanwhile acceleratiing, the entire body weight is supported directly over the springing of the rear legs, like a kangaroo, but leaning forward at hyper speed.

think about it, with perfect traction, the mx bike should have its front wheel unweighted on acceleration. down the strAIGHTS, OUT OF TURNS, you have no need for the front wheel to be balanced with the rear, because it floats ever so slightly above the ground.

this is the design function of the stinkbug effect. it is a functional design.

you accelerate down a straight, weight is centered over the rear suspension, shifting up, until a last minute breaking, which should in lapsed time, touch down, decel and pivot, only to unweight out of the turn and down the next straight.

many riders, blaming the bike for being too high in the rear, unknowingly dismiss this funtional concept.

Edited March 9, 2010 by Scrubba

[Skotten]

Interesting therory, and thats why 'i get less, well actually less arm pump with this bike because the front has less wieght on the ground, less resistance to hold on to.... hmmm food for thought..

[Skotten]

Well the sun is out office dark and boring, time to inch my way to the nearest exit, crawl to the car, race home and break out my bike. Get the beast onto the frozen lake. Maybe i´ll get 5th gear....

If you dont here from me again we sank somewhere....

[grayracer513]

This technique states, that like the scampering fieldmouse, the only time the front legs need to touch the ground are in the turns.

Back in the day, when the bikes had 6" of fork travel IF they were the cutting edge stuff, that's how we made up for the lack of adequate front suspension...

In an ideal world, though, the more the wheels stay in contact with the ground, the more control you have. Still, the mouse may be onto somethig.

[Skotten]

The mouse should be pretty good over the whoops.

[Skotten]

Talking about wheel contact... and high front wheel over jumps ect (original topic)

When I was out on the YZ I felt it was a bit twitchy (At the track last weekend hard packed snow and ice) backend twitching, and the front end slid... So today, I took it out on the lake on just ice and it was wobbly, and unstable. Took it down the road (snow, ice and asphalt) front wheel wash out on the asphalt... Baffled on the way home, thinking about all I read on handling, suspension ect, did I buy the wrong bike?? So when I was drying off the new bike, looking at my old bike, thinking "at least you don´t slide all over the place" I glanced at my tires. Glanced at the tires on the new bike, which I got from a friend..

Front tyre

The stud pattern is not the same as the tyres on the

CRF more studs, better stud spacing, better pattern on the new Yz less studs three rows in a strait line, the second row of studs are blunt.

Back tyre had the same problem but new studs which are blunt now plus they are enduro tyres.

So I guess the back wheel was spinning too fast off the jumps. The bike didnt feel like it was pulling hard, thus causing high front wheel over the jumps. I actually think they are cheep enduro tires.