Rear end gets squirly

[Mick17]

I've noticed the rear end on both mine and sons bikes get squirly (it moves side to side) at higher speeds. I'm thinkin tire pressure. I'm runnin 13.5 in the rears and 10 in the front. Tires are stock (dunlaps 756 in rear and 742fa in front) Both bikes are 2010 yz450's.I also set the suspension to the MXA suggestions (a little softer as we are lighter) Thanks for any help

[clutchless]

Race Sag set up wrong? It could be too low, the result will be a twitchy rear end and head shake at speeds.

[grayracer513]

Try turning the rebound adjuster tighter by 2-3 clicks at a time and see if it improves.

[Scrubba]

isnt 10 lbs front way too low? i run 13f 13r

[CaptainKnobby]

I run 12 in the rear on mine and 13psi in the front. I ditched the front 742f on the front of mine cause it made the bike want to slide around a lot in the front.

The 742's are trash! Depending on how much you weigh (if it is 200 or more) you may want to try and run 100mm of race sag or a little less to reduce preload.

[Mick17]

The race sag is 58-60mm.......but that is with the preload adjusment all the way out!!! Maybe I need to put some lead in his butt!!! LoL......Do I need to go to a lighter spring? I have always run less air in the front tire (or tires) for off road........I like a little tire spin and the front to "stick". If I run the same or less pressure in the rear it will "push" the front end

I measured the race sag wrong.....my first measurement was a static. I'll get the right measurement tonite

Edited June 14, 2010 by Mick17

[Mick17]

Try turning the rebound adjuster tighter by 2-3 clicks at a time and see if it improves.

When you say "tighter".....do you mean to slow down the rebound? Thanks

[monkeymotocross]

i run 15.5 pounds of pressure in all my tires

[Phil Hannah]

Sounds like you need lighter springs. 70mm race sag is a recipe for disaster!!!!

[Mick17]

Measured it correctly and it's 100mm (hair under 4 inches)

[idigdirt]

I had the same problem with my 2010, I tried a Kenda Southwick and it was terrible same problem so I just switched to the Pirelli Scorpion MXMH 454 and have 4 rides on it and it rides like it's on rails no more wiggle. Hope that helps......

[kalvin22]

check to see if the spokes are tight, sometimes they take a while to seat in.

[Dylan8kawasaki]

Also make sure your wheels are running true. I had bought some new rims and at high speed they wobbled more than the stockers. Once I trued the rims the problem was solved.

[Scrubba]

The race sag is 58-60mm.......but that is with the preload adjusment all the way out!!! Maybe I need to put some lead in his butt!!! LoL......Do I need to go to a lighter spring? I have always run less air in the front tire (or tires) for off road........I like a little tire spin and the front to "stick". If I run the same or less pressure in the rear it will "push" the front end

I measured the race sag wrong.....my first measurement was a static. I'll get the right measurement tonite

stick alright, wait till it sticks to a rock and bends your rim at that pressure.

[Mick17]

stick alright, wait till it sticks to a rock and bends your rim at that pressure.

Glad you said somethin.....was thinkin of droppin to 9 in the front and 11 in the rear.

What is the lowest pressures you would go?

[Scrubba]

Glad you said somethin.....was thinkin of droppin to 9 in the front and 11 in the rear.

What is the lowest pressures you would go?

lowest i go on a 450 is 13 lbs. highest i go is 14, but thats just preference.

too high, and the ride gets harsh. also you can tell if its too high, you wont see the rim bead effect on the rim when you ride.

[CaptainKnobby]

with say....95mm to 102mm race sag you will want around 25mm to 40mm static sag.

I couldnt hardly get this until i had my suspension redone. now i have 102mm race sag and 35mm static.

It really rides well now and is very plush through the whole stroke,but I had to turn loose of a chunk of change to get it like this.

[Scrubba]

where did you get it done?