Sag settings...

My rear end suspension on my 05 450 feels pretty soft. I have been trying to get it dialed in recently. I have been reading a lot on Sag, but still have a couple questions....

Here are my measurements....

625mm (this is with me holding the backend all the way up - tire off the floor)

595mm (this is the bike with it's own weight)

505mm (this is with me on the bike)

I am confused because the sag is at 90mm, but seems like some people measure from fully unloaded, and some with the bike sitting there on its own weight. :)

It just feels really soft to me.

Any advice would be awesome! Thanks! :D

Your sag is 120 MM.

You measure with the bike on a stand and then with you and all your gear on.

Deduct the second from the first and you'll have your sag.

Because I'm a fatty I have to buy heavier springs for every bike I own.

Just watched the "sag" video again....

Looks like my Free sag is 30mm, and my rider sag is 90mm.

Why does it feel so soft and seem so low?

BTW, I am 6'2, 210 (with gear).

Race sag is measured with the bike fully unloaded (with the bike on the stand) vs. fully loaded (with you and all of your riding gear seated on the bike). The diffirence between these two measurements should measure 100-105mm depending on the handling characteristics you are trying to achieve. 100mm will yield better handlling for tighter turning, and 105mm will give you more stability for open desert riding. Free sag is the measurement between fully unloaded vs. fully loaded (weight of the bike only without you sitting on it) and gives you an indication of whether or not your shock spring is correct for your weight. Generally, between 15-25mm is the accepted norm. Less than 15mm means the spring is too soft, more than 25mm means the spring is too stiff. Free sag should only be checked after the race sag has been set.

I agree with beezer, your race sag is set at 120mm. You need more pre-load.

Preload, is that AKA Free sag??

So can I get more preload by cranking up rings some, or what will that adjust?

Thanks for the great responses so far! Sorry for the newbie questions.

Pre-load just means you have to add more spring tension to the shockspring via the shock spring pre-load adjuster rings.

10-4.

Thanks for clearing that up guys! :)

Set your race sag (rider sag as you mentioned) first, with all of your riding gear on, then measure the free sag to give you an indication of whether or not your shock spring is too (probably) soft.

Its weird but many times stiffer springs with less preload make for a better ride.

Too much preload and the suspension dosn't work well.

One more question for setting up the preload....

What is the best way to get to the spring for adjustment, should I take the airbox off?

Also, do I need to adjust by feel, or can I measure the spot on the spring where it is now, then measure 15mm up and just adjust it to there?

Thanks!

I completely agree with Beezer!

I am about 210 with gear and I installed a 5.8 Eibach over the winter. It totally changed my bike. With less preload on the spring, the suspension is more compliant and tracks small bumps better. I also have much less chatter from the rear tire under heavy braking.

Now that the bike rides higher in the stroke, it steers quicker and is easy to flick around. It jumps better too since the rear doesn't blow through the stroke on the face of the jump.

I should have done this before I started the bike.

If your bike is clean you can loosen the upper lock ring with a long dull flat blade screw driver and a BFH.

I put the bike up on the stand and I can usually turn the spring by hand and the lower locking ring follows the spring.

If you are big and you put in to much preload you'll have a stink bug.

I just call up Factory Connection and have them send me the springs.

Many times you need less compression dampening and more rebound.

It sounds like a lot of work but TV sucks and the old lady is usually pissed at me anyway.

No, you cannot measure the perload on the spring 1:1 with the expected result at the rear. Because of the extreme leverage the wheel has on the rear shock, it's more like 8:1 or thereabouts. Far better off to adjust and measure the results.

Sleighdriver's assessment:

Race sag is measured with the bike fully unloaded (with the bike on the stand) vs. fully loaded (with you and all of your riding gear seated on the bike). The diffirence between these two measurements should measure 100-105mm depending on the handling characteristics you are trying to achieve. 100mm will yield better handlling for tighter turning, and 105mm will give you more stability for open desert riding. Free sag is the measurement between fully unloaded vs. fully loaded (weight of the bike only without you sitting on it) and gives you an indication of whether or not your shock spring is correct for your weight. Generally, between 15-25mm is the accepted norm. Less than 15mm means the spring is too soft, more than 25mm means the spring is too stiff. Free sag should only be checked after the race sag has been set.
...is precisely right, as is beezer's observation that a too stiff spring will ride better than a spring that's too soft by the same amount. That's because with a soft spring, the only way you can keep it from bottoming is to crank up the compression damping, and the ride gets overly harsh.

Read more:

First: http://www.tootechracing.com/suspension_tips.htm

Then: http://www.tootechracing.com/Static%20Sag%20Suspension%20Tip.htm

You can, if you choose, use a soft punch ( I use a length of 1/8 x 1" aluminum bar stock, but don't tell anyone; I'm supposed to be a pro or something :) ) and rotate the rings that way. Just don't get too heavy handed, and make the adjustments while it's on the stand to take as much pressure off the spring as possible.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now