why !!!!!

[GOTFEAR]

You know that the 250r is a legend being the best mx bike on this planet my question is every major manufactured built their atv's from the 250r. So if that is true why dont the other frames on the front bend up like the 250r and the four strokes frames are flat why so different

[All250R]

I think the 450R has the a-arms tilted upward, and I think the 09 YFZ450 does too. I'm definitely no expert here. You need to ask a chassis engineer what the pros and cons are. Not every design that is good on one setup is good for another.

[racerx573]

It's called frame rake.

It's a geometry characteristic.

Think about how that angle assists when going in forward motion in rough terrain.

A lot of the newer bikes DO have it, just not as much, and the rake may start at different points on the frame.