Rear Spring Question?

I have 33mm static sag with 5.5mm of preload ,and 114mm rider sag on my FC 550 05.
Do you guys think I need a stiffer spring to get the 105-110 numbers to work out,or is this close enough?
Thanks for opinions!
I have an 8.8 and 4.8 set up for Moto,and go 212lbs no gear? :?:

you are miles and miles out!

you need 100mm sag on the later bikes and not 110mm? so where you got that from/ must be a book i haven't seen yet!

look at a 9.25 or preferably a 9.5 straight rate. MxT do a PDS9 which is a progressive 9.0-11.5 and this i totally recommend.

regards

Taffy

These Springs Change?

I just found my numbers from last year and they were 35/110 and with some time on them are now 33/114.

I did add some preload with a little over one turn but they did drop some.
Is this normal Taffy?

My KTMs get me screwed up on my numbers as they like 110-115. I forgot the Bergs need less. I will get a 9.25 as it seems very close.

Thanks,

mark550fc said:

I have 33mm static sag with 5.5mm of preload ,and 114mm rider sag on my FC 550 05.
Do you guys think I need a stiffer spring to get the 105-110 numbers to work out,or is this close enough?
Thanks for opinions!
I have an 8.8 and 4.8 set up for Moto,and go 212lbs no gear? :?:

Click to expand...

Hi Mark,

I am about 200# with all my gear on. My 04 550 is set up for desert senior amateur. I have a pds #8 with .44kg springs and both ends re-valved. That gives me between 95-100mm of rider sag.

There are several ways to check your sag, and just the smallest amount of different body postion can result in a change of 10mm pretty easily. One of the best I've heard of is to stand on the pegs while your assistant checks the measurement. And, if you want to be really accurate you can take the measurement this way. While standing on the pegs hands on the grips, have your assistant push down on the rear of the bike gently and then let it up, take a measurement. While in the same position, have your assistant lift up on the rear of the bike and then let it down gently, take a measurement. Now just splilt the difference between the two and you're there. This eliminates the stiction in the seal head giving a false reading.

I believe that Taffy is right in suggesting a progressive rate spring. The needle profile of at least the 04 was short and fat, and the progressive spring works well with this set up. However, if you are still running the stock valving you are probably going to have some "issues". There probably won't be enough rebound damping in the main stack to take care of the extra energy that will be produced by the stiffer spring. Cranking in more rebound damping via the clicker is not going to solve your problem there I'm afraid.

You are right on with the amount of spring preload though. On my set up, I have exactly 5mm of spring preload, which in turn gives me 33mm of static sag. Once you get everything sorted and have the static measurement, it becomes very easy to check.

Where are you located??

Shock Was Revalved for Straight rate

Dicks Racing set it up last year so it should have plenty of rebound , I will try the 9.25.
I had a progressive on it with the revalve and it was strange to deal with. I talked to **** Wilk and he said it was because of the revalve,so I will need to keep it straight since the work has been done.
I live in the Reno/Sparks area of Nevada with plenty of room to ride.
Thanks for the help guys,