Rear end gets squirly


17 replies to this topic
  • Mick17

Posted June 13, 2010 - 06:20 AM

#1

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

Posted June 13, 2010 - 12:02 PM

#2

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

  • grayracer513

Posted June 13, 2010 - 01:32 PM

#3

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

  • Scrubba

Posted June 13, 2010 - 02:14 PM

#4

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

  • CaptainKnobby

Posted June 13, 2010 - 04:24 PM

#5

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

Posted June 13, 2010 - 05:16 PM

#6

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 by Mick17, June 13, 2010 - 05:55 PM.


  • Mick17

Posted June 13, 2010 - 05:18 PM

#7

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

Posted June 13, 2010 - 05:48 PM

#8

i run 15.5 pounds of pressure in all my tires

  • Phil Hannah

Posted June 13, 2010 - 06:21 PM

#9

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

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Mick17

Posted June 13, 2010 - 06:35 PM

#10

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

  • idigdirt

Posted June 13, 2010 - 06:45 PM

#11

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

Posted June 13, 2010 - 06:50 PM

#12

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

  • Dylan8kawasaki

Posted June 13, 2010 - 06:57 PM

#13

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

Posted June 14, 2010 - 01:40 AM

#14

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

Posted June 14, 2010 - 04:53 AM

#15

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

Posted June 14, 2010 - 08:53 AM

#16

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

Posted June 14, 2010 - 11:42 AM

#17

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

Posted June 14, 2010 - 11:31 PM

#18

where did you get it done?





Related Content

 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.