What is static sag for '08 450F??? (rear suspension)


5 replies to this topic
  • rdefonce

Posted April 27, 2009 - 04:44 AM

#1

For some reason (brain fade, or????) I can't find the static sag measurement in my '08 YZ450F manual. It only shows race sag.

Does anyone know what the static sag (bike on ground, no rider aboard) should be?

The race sag is correct (me w/all gear on bike) BUT I need the static sag range to determine if the spring is in the ballpark. Thanks!

  • wondermuscle

Posted April 27, 2009 - 06:11 AM

#2

I believe the Static sag should be about 30mm or approx 1.18".

  • grayracer513

Posted April 27, 2009 - 06:17 AM

#3

The reason you can't find it is that they don't give it, but like WM said, it should be about 25~30mm if the spring rate is correct. If your spring is too light, you will have less free sag once the race sag is set. If the spring is too stiff, you'll have more.

http://www.tootechra...pension Tip.htm

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

Posted April 27, 2009 - 06:23 AM

#4

Thanks for the info guys.
Yamaha should put that in the manual!

I'm thinking my spring is pre-loaded too much (to reach correct rider sag numbers), giving me a harsh ride. I'm checking static sag soon as I get home tonight.
Cheers!

  • grayracer513

Posted April 27, 2009 - 07:05 AM

#5

The sag adjustment will not noticeably affect the harshness or plushness of the ride. It only sets the preload of the spring, and cannot affect the rate, which stays constant.

Only if the preload were set so you have no free sag at all would you begin to notice something. Remember that this condition usually occurs with springs that are far too light. Too soft springs result in the rider cranking the damping up to a higher than normal level to compensate for the lack of compression resistance in the spring itself, and in extreme cases, the spring can be preloaded so far that it coil binds at full suspension travel.

Springs that are too stiff often ride better than those that are too light.

  • rdefonce

Posted April 27, 2009 - 08:27 AM

#6

The sag adjustment will not noticeably affect the harshness or plushness of the ride. It only sets the preload of the spring, and cannot affect the rate, which stays constant.

Only if the preload were set so you have no free sag at all would you begin to notice something. Remember that this condition usually occurs with springs that are far too light. Too soft springs result in the rider cranking the damping up to a higher than normal level to compensate for the lack of compression resistance in the spring itself, and in extreme cases, the spring can be preloaded so far that it coil binds at full suspension travel.

Springs that are too stiff often ride better than those that are too light.


Gray, makes sense.
I experienced way too soft spring on my KTM200, which caused shock to move (too quickly) into higher compression damping range. A heavier spring helped a lot, and did what you said; made the ride more plush!

Chances are, my 450F spring is NOT too light for me, since I'm only 165 w/o gear. Hell maybe it's OVER sprung. I don't know what spring's on it; it's a silver (titanium?) colored spring, even though I bought the LE white model (used) . . . maybe they just swapped plastics, OR replaced the stock red spring.
Just like a stray dog, don't know it's past history, just trying to give her a good life from now on! :banghead:





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.