so i got around to checking sag settings on my 10 ec300... 41mm static and 95 with me on it (no gear)... seems like the static is a touch on the high side and race is a touch on the not enough sag side. What is this telling me? i expected since i had a little to much static i would have a little to much race but maybe im wrong. so what is my next steps? do i ad some preload to get the static a touch less? bike has sachs rear shock. Thanks for your help...PS in 220 no gear, bike has stock springs
sag settings....
- Thread starter BryanMcc
- Start date
Jakobi
Super Moderator
Classic indication of the spring being too stiff for you.
If you wind more preload on you will reduce the static sag will reduce, however the race sag will also reduce. If you back the preload off the opposite happens, where you'll end up with more static and race sag.
How much preload have you got on the spring at the moment? Find it hard that at 220 the stock 5.2 spring would be acting that way. I'm 200-220lbs in full gear and coated in mud and the run a 5.4 rate spring.
If you wind more preload on you will reduce the static sag will reduce, however the race sag will also reduce. If you back the preload off the opposite happens, where you'll end up with more static and race sag.
How much preload have you got on the spring at the moment? Find it hard that at 220 the stock 5.2 spring would be acting that way. I'm 200-220lbs in full gear and coated in mud and the run a 5.4 rate spring.
how do i check the preload...i looked over the forum a little bit, seems there is some info on both the sachs and the ohlins shock.. im with you on not understanding why the stock spring is stiff. exact opposite of what i ecpected... sunday morning a will take a measurement when im all geared up... the measurment i took was just me, no gear, so im probably 20-25 lighter than normal. what sag do you like Jackobi? hey thanks for all your help by the way... i think i have my jetting issues sorted, we will see on sunday, all the way down do a 165 main on a as2 38mm, jd red middle pos and 40 pilot. seems lean to me compared to others.... 4500 to 7000k feet 80 deg low humidity.
Jakobi
Super Moderator
Does seem lean but you have some decent elevation and temps going on. If you worked your way down to it and are happy with the results, the bikes not showing signs of being lean and the plug chops look good then thats that sorted. I generally go for the needle clip position first up as it makes the biggest effect across the widest range of throttle.
Back on topic. Best advice I can offer is to pull the shock out. You can do this by undoing the lower subframe bolts and loosening the top ones and flipping the whole back of the bike up. You'll have to undo the dog bones on the linkage to swing them forward to access lower shock mount. Once you have the shock out mark where the spring is compressed to, and then back the spring off until its no longer compressed. The distance between these marks is your preload (uncompressed spring - compressed spring = preload). It should be around 10/12mm.
While you are at it its a great time to lube the linkage bearings and ensure the swingarm moves freely through its range of travel without binding. You can then either order a new spring, or consider testing the one you have to see what rate it is.
Back on topic. Best advice I can offer is to pull the shock out. You can do this by undoing the lower subframe bolts and loosening the top ones and flipping the whole back of the bike up. You'll have to undo the dog bones on the linkage to swing them forward to access lower shock mount. Once you have the shock out mark where the spring is compressed to, and then back the spring off until its no longer compressed. The distance between these marks is your preload (uncompressed spring - compressed spring = preload). It should be around 10/12mm.
While you are at it its a great time to lube the linkage bearings and ensure the swingarm moves freely through its range of travel without binding. You can then either order a new spring, or consider testing the one you have to see what rate it is.
pscook
Platinum Level Site Supporter
To set preload you don't have to remove the shock, you can can set the bike on a box with swingarm unencumbered and wind off the preload ring until the spring spins by hand. That is zero preload. Then wind in ten mm of preload and see how it acts, adding more as it's needed. I know that my Ohlins shock has 1mm of preload for each rotation of the preload ring, which makes it quite easy to set the sag. Les from LTR has a sticky (click right here) to apply correct preload, but it is for 2004-2006 models and I don't know how it would translate to a '10. According to the sticky you want 105-108mm of sag, and I found this to be true as 95mm of race sag for me caused the bike to be too twitchy, and the extra 10mm of sag helped out a bunch.
Jakobi
Super Moderator
Very true that you can indeed set the preload with the shock on the bike. I was just suggesting removing it and checking the linkage and swingarm as well as either of these binding will also affect the performance of the shock and how well it moves through its stroke. My old man had the linkage in his WR seize so bad that the back end felt rigid. It wasn't the shock, spring or preload causing it 
Hope that helps.
Hope that helps.
Jakobi
Super Moderator
Not sure how to test one. Think you should be able to sit a certain weight on top of the spring and it should compress a certain amount. See how it all ends up. Another thing is to try and take your measurements from an area that will remain verticle. I use a crew driver with a string fixed in the rear axel and then run it straight up to the rear fender.
swazi_matt
Active member
I found a web site that works out spring rates based on wire size an coils etc. will post it here on Tuesday when I am at my computer. Not sure how accurate it is as I would imagine various manufacturers use different sizes, but based on your measurements we should be able to compare it to other springs on the forum
swazi_matt
Active member
Unless you are actually asking what spring rate you should be using? Then a starting point would be the racetech site (or asking here
swazi_matt
Active member
Jakobi
Super Moderator
How'd you go? Did you find out if its the stock spring or not? Anything binding? Just a bad measurement last time?
When I get home tonight I'll post what it came out to as far as race sag goes, still has 41mm of static which I think is wierd(a little much static and ok race sag in stick spring). I didn't really feel anything binding either but all day Sunday and Monday I was plagued with a power valve that I believe sticks open After a section where I'm heavy on the throttle. A couple times I had to climb a hill in first gear that I normally rip in third, wouldn't even come on the pipe in 2nd. So it was tough to focus on suspension when every few mins it would act like this. I have a race coming up Oct 7th so I better get this thing dialed in!
