which spring

jeffs2200 · May 20, 2007

I just got a new to me 02 fe501 and being as I am a big guy ( 6'3" and apprx. 320 lbs) I need to change out the rear spring. I was wondering if anyone knows what spring rate or spring # would work best. I am also a little confused about setting preload. I read the wp manual and when they talk about measuring for static drop it says to place the bike on a stand with the rear wheel suspended and take a measurement. then re-measure (without rider) does this mean the rider should be mounted in the first measurement? If not why measure twice as there will be no difference if you have not made any changes. It then says to measure with the rider on the bike to figure the total drop. I think that this makes sense, I am just confused about the static drop measurement. Any help would be greatly appreciated. I am really excited about my Berg and I just want to get it set up right.

Shonky13 · May 20, 2007

Hello jeffs2200,

Static sag is measuring how much the bike's own weight (no rider) "sags" the suspension. By putting the bike on a stand (rear wheel off the ground) you are relieving the rear spring of any weight. Take the bike off the stand (keep it upright) and you are loading the spring with the bikes weight. The difference beteween the 2 measurements is the "static" sag. Adjust to the recommended setting (mine is 35mm).

Then measure "race" sag. Race sag is the measured difference (from static sag) with the rider onboard in a neutral position (with all his normal gear on). If it is more than the recommended sag (mine is 95-105mm) then the spring is too soft, if it is less, then the spring is too hard.

By measuring both static and race sags you can determine whether you need a different spring or not. If the spring is too heavy or too light you'll never be able to set both sags to their ideal settings.

I've recently measured my '07 FE550 sags with the standard spring (WP 84/250). Both were OK even though I'm around 95kg(210lb - without riding gear) and the spring is recommended for 74-87 kg (163-192lb - with riding gear) :? . Maybe I'll need to remeasure when the suspension has bedded in a bit more - but the point is, you will need to find the right spring by trial and error using recommended weights as a starting point.

Sounds like you don't have the bike's manual. Have a look at http://www.husaberg.se/Downloads.33.0.html - you may find your manual there to download. My '07 manual has a good explanation & diagrams of how to set preload etc. plus a bit on heavier springs (forks as well) - although the manual only specifies springs for riders up to 97kg (214lb).

Have fun

buzzard · May 20, 2007

Jeffs, there are three measurements. First, with the bike on a stand, no weight on the wheels, measure from the rear axle to a point on the chassis above the axle. Second, with the bike on the ground, under it's weight alone, take the same measurement. Third, with the rider on the bike, all geared up, take the same measurement again. It helps to have an assistant to hold the bike vertical. The difference between the first and second measurement is the static sag. The difference between the first and third measurement is the rider sag. With the correct spring, the static sag and rider sag will be within specified dimensions. I cannot guess the spring weight you will need, but I think some of the suspension shops that sell springs might have a good guess at it. Good luck!

Johnf3 · May 20, 2007

There won't be an off the shelf spring available that will work with 320 lbs, at least not a factory WP spring. The older WP shocks, like your '02, also used heavier spring rates to start with, so comparing what works on an '07 Husaberg will be a bit confusing.

I'd call up Cannon Racecraft, located in Oklahoma City. They manufacture many springs for other aftermarket suspension companies, and are good to deal with. They will have a spring that will work for you. I'm guessing you will need a straight rate spring rate around 10.6 or higher.

jeffs2200 · May 20, 2007

I appreciate the advice. I was reading from the wp manual and it just was not clear but that makes much better sense. I was wondering if someone could tell me how to identify whether a spring is stiffer?I believe the stock spring is a pds4. Does a higher # indicate stiffer or does a lower# mean stiffer. For example would a pds 2 be stiffer than a pds 6? Also does the longer the length make it a stiffer spring or does a shorter spring make it stiffer, or maybe I am just confused and that does not matter. :?

Johnf3 · May 21, 2007

jeffs2200 said:
I appreciate the advice. I was reading from the wp manual and it just was not clear but that makes much better sense. I was wondering if someone could tell me how to identify whether a spring is stiffer?I believe the stock spring is a pds4. Does a higher # indicate stiffer or does a lower# mean stiffer. For example would a pds 2 be stiffer than a pds 6? Also does the longer the length make it a stiffer spring or does a shorter spring make it stiffer, or maybe I am just confused and that does not matter. :?

The stock WP progressive springs # 1-4 are 250 mm in length with 4 being heaviest. PDS # 5-8 are 260 mm in length with 8 being the heaviest out of those four. The spring length changed in '03 because the shock length increased, I think. Length has no effect on stiffness.

I think your stock spring rate was a PDS 2. For sure not a PDS 4. PDS 4 is the heaviest progressive spring WP makes.

Here is a WP PDS spring chart. C1 is measured at 20mm compression and C2 is measured at 100 mm compression.

PDS #0 C1 6.5 C2 8.3
PDS #1 C1 7.0 C2 9.0
PDS #2 C1 7.5 C2 9.7
PDS #3 C1 8.0 C2 10.3
PDS #4 C1 8.5 C2 11.0

New Generation
PDS #5 C1 6.6 C2 8.8
PDS #6 C1 7.15 C2 9.05
PDS #7 C1 7.6 C2 9.5
PDS #8 C1 8.1 C2 9.95

At your weight, you should go with a straight rate spring. A progressive won't give you proper sag numbers.

Taffy · May 21, 2007

there is a PDS9 available from MxT and it's a 90-115 i believe.

regards

Taffy

Johnf3 · May 21, 2007

Taffy said:
there is a PDS9 available from MxT and it's a 90-115 i believe.

regards

Taffy

I am running that exact spring, although it is from Factory Connection. It still wouldn't be near enough spring for 320 lbs, though. I am 230 lbs and it works about right for me.

Taffy · May 21, 2007

i was going to say - it is the nearest!

i believe my PDS4 to be just a little shy of strong enough for me. i figure that if i was 210 or 95kg it would be fine. i want to try the PDS9 sometime but i have to get into the valving soon.

spring first or valving: this is the question.

regards

Taffy

jeffs2200 · May 21, 2007

I appreciate all the advice. I contacted Cannon racecraft today and they were very helpful. They suggested a fixed rate spring of 10.8 or a progressive with a rate of 9.5-13. My question now is which would be better. I live in Texas and most riding will be in sand, rocks, ruts some jumps and that type of thing. I might play around on an mx track but that is not a main focus. I do not plan on doing any enduros or hair scrambles yet but I might decide to do so in the future.

Johnf3 · May 22, 2007

jeffs2200 said:
I appreciate all the advice. I contacted Cannon racecraft today and they were very helpful. They suggested a fixed rate spring of 10.8 or a progressive with a rate of 9.5-13. My question now is which would be better. I live in Texas and most riding will be in sand, rocks, ruts some jumps and that type of thing. I might play around on an mx track but that is not a main focus. I do not plan on doing any enduros or hair scrambles yet but I might decide to do so in the future.

For a progressive to work, you really need the initial starting rate to be the same as what it would be in a straight rate spring. Otherwise, you probably can't get the sag set correctly. That's why I said to go straight rate. If they had a progressive that started at 10.8, then you would be good.

Progressive springs give an extra measure of bottoming control and keeps the shock from blowing through the travel so quickly, but not everyone likes them. They aren't as plush as a straight rate spring on enduro-type obstacles, like rocks, ruts, and big braking bumps.

Taffy · May 22, 2007

not much in it. i think that 9.5 is way too soft as a start point for you though so go with the straight rate.
regards

Taffy

which spring

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