I went on race tech's site and looked for fork springs for a klx300 and got the part number, then there just happen to be those exact springs on ebay a little bit cheaper. So i dont know exactly what the diameter is. This is what race techs site says:
FRSP 394644 RT FRK SPR 38.2x455mm .44kg

For those of you that have put new springs in, what did you do with the compression adjustment on the bike? I had it all the way up due to under sprung springs... but with the correct springs what have you found works best?

 

I went to the Ebay place. MY SF has a 6.8 stock rear spring acording to race tech and John at moto pro. I emailed the folks at the Ebay store. They said they have no spring that fits my bike .

Race Tech also says I need a 7.2 for a 200 lb person. Available from Moto Pro only as far as I know. This is for an SF.

David

 

That doesnt make sense, i put in im 220lbs and race tech says:
REAR SHOCK SPRING
Recommended Rear Shock Spring Rate: 6.08 kg/mm (use closest available)
Stock Shock Spring Rate: 5.8 kg/mm (stock)
FRONT FORK SPRINGS
Recommended Fork Spring Rate: 0.484 kg/mm (use closest available)
Stock Fork Spring Rate: .380 kg/mm (stock)

Moto pros website reccommends a .44 spring in the front, and a 6.2 in the rear.... Thats what i got... but i got race tech fork springs and the DSP rear spring....

holy crap..... the springs are that much different in a supermoto?
Rider Weight: 220 lbs

FRONT FORK SPRINGS
Recommended Fork Spring Rate: 0.484 kg/mm (use closest available)
Stock Fork Spring Rate: 1.150 kg/mm (stock)
No Fork Spring Series currently specified for this model.
Please call Tech Support 951.279.6655 for help.

 

With all my offroad bikes, I could never trust the RaceTech info. After passing along the info to my tuner, he agreed that the rates were too light for me. The RT calculator always undersprung me. 5.8 stock to a 6.08 almost doesn't seem worth it? Of course motard-type stuff doesn't call for the big-hit soaking suspension.

I have .38's in my klx331 with kx500 forks. It is somewhat on the light side as I can bottom them(dangerously so) in the whoops but they pick up trailtrash well. I'm going with .43's and maybe a revalve...this is in line with my other bikes in terms of spring rate. Good luck!

 

Yeah, it's been a bit of a surprise to me too on the difference in the SF springing and apparently the damping. It's quite different. I also went with .44's in RT fork springs for the '06 KLX300. I went with a 6.0 Eibach shock spring from the '06 KLX300. It's 15mm longer than our '06 KLX250 spring, but it fits with no issue. Oh, I forgot to add that the 394644 RT spring is what I used on those .44's. And I'd give you my compression adjuster specs, but my damping isn't stock and won't be similar.

 

Im pretty excited about the new springs, i always had to be conscious of how hard i ride because of the weak springs, couldnt get real high off the ground or it would be bad....

 

Well, I see the problem EMS. From that picture it's obvious you're riding an SF and trying to ride it like a dirt bike. Get rid of that low rider and get an "S" model...LOL!

Man oh man!...you are crunching that suspension there, aren't you.

 

This is the SF model with stock front and rear suspension. Rear racing sag is around 60 mm. ALL the weight is on the rear wheel right now.

The bike corners in the city like crazy. 30 mph at an intersection, just turn...



The super moto or Motard version is 1" lower than the S. It feels pretty good riding around. Ever since I bought it, the rear felt softer than the front. Rear tire would get warm when the front would not. SO I tried raising up the rear end just by decreasing the sag and it did not help much. I was thinking rear higher would put more weight on the front just like anything else.

BUT since the bike is 1" lower, folks say the longer links make the suspension more progressive and softer. I believe it, that is why the 6.8 spring on my bike and 5.8 on the S model. The manual says its built for a 160 or 180 lb driver just like the S model. SO to have a stiffer shock/spring setup, I could go with a shorter link, but then the bike would be too tall for me. My link says "119.5" and I measured it. Center to center for the holes it is 119.5mm.

David

I can tell you a small adjustment on the rear preload changes the sag a lot.

I am a road bike rider, this thing handles on the blacktop like it should. Get off this and get on my BMW1100. At first I feel like I am riding a bucket of mush. BUT go a few hundred miles and Ahhhhh...

I have bottomed out the front just once and that was trying to do a stoppie. CLUNK! I do not remember bottoming out the rear. I have since set the rear sag to 75mm or just over 1/3 of the rear suspension travel. Still snow, so I can't report on the results. Its killing me...... 14*f this morning with gusts of wind up to 40 mph. Frikkin cold!

 

You can bottom on a stoppie? That seems soft. I used the same settings when I swapped to my motard wheels on klx4 and it felt good on the street....also felt like it could turn on a dime. Shows what a good revalve does!

 

Was this landing from a jump?