Fork springs

[1989kawasaki]

so i am changing my springs to the stock setup cause its too stiff now.

so in my box of springs , i have 2 pairs of fork springs , one pair has 48 etched in the top, the other says nothing

any ideas as to what "48" means?

[DoldGuy]

The springs weight is measured in Kg....the 48 probably is a .48 Kg spring rate. The thicker the metal the stiffer the spring, same size of metal with looser coils (more are between) the stiffer.
Hope this helps,
DoldGuy

[1989kawasaki]

The springs weight is measured in Kg....the 48 probably is a .48 Kg spring rate. The thicker the metal the stiffer the spring, same size of metal with looser coils (more are between) the stiffer.
Hope this helps,
DoldGuy

Thanks. but would .48kg suit a 180lbs rider?

[DoldGuy]

Working from the iPhone....can't get to the spring chart. By your previous post you have the manual for your bike, what is the stock spring rate? Way back when & many pounds ago, I had the 1988 KX250 & weighed 155lbs, the stock springs were too soft for me & needed stiffening. Have you bled the forks? What oil level are you running in them? Oil weight? These things have a big effect on the "stiffness" of the forks.

In my opinion, the bikes of that era definitely need stiffer springs for today's style of jumps/tracks & have been told the "Big" conventional forks on yours were far superior to the inverted forks in that era. If you go to racetech.com they should have a spring chart that should help too.

DoldGuy

[1989kawasaki]

race techs calc. says the stock rate is .366kg/mm
and for 180lbs they recommend .45kg/mm (use closest available) which is .46
and im sure after the weight gain after putting on all the heavy gear , then i would suit a .48kg rate.

and the stock rear spring would suit me just fine according to the calc. 

i do bleed the forks sometimes, 5wt oil, no idea on the level (shop did the seals and oil for me)

so you think .48 is good?

[DoldGuy]

That's pretty significant over the stock .36, what rate springs are in there now?

[1989kawasaki]

That's pretty significant over the stock .36, what rate springs are in there now?

no idea. but ill guess ill find out soon

[1989kawasaki]

i took some pics

on the left is the .48 springs. i wonder why the others are longer 
do you know what the pipe and the washers do??

please excuse the mess.. i was out cleaning today making room for bikes

[DoldGuy]

The tube/pipe should be a spring guide, washers protect the fork caps if memory serves. Those springs do not fit the same set of forks. Check your manual for the free length specs to determine which (if either) fit your forks. The springs on the right are definitely stiffer as you can see the difference in coil length. The forks should have some sag as the rear shock does & with the springs you have there, one would have no sag & the other would have way to much. Get into that manual & start measuring.

[1989kawasaki]

ok so the free length is supposed to be 56cm. and the longer springs are 56cm. shorter ones are 51cm

[Friar-Tuck]

Do you think there may be a spacer missing from the shorter springs?
 I could swear both  my XR and CR both had a small  2-3" spacers that went at the top of the springs to
 "Pre-load" them  (I'm thinkin')
   Tuck\o/

[1989kawasaki]

d**n.. i cant get the fork caps off.. they are rounded off .

what do i do now? is it even possible to fix the rounded top caps? or should i buy the forks off ebay for $35?


some of the damage was there before. i didnt do all that damage. just made it a little worse

[DoldGuy]

Take out the top triple tree bolts, it clamps down on the fork caps.
DoldGuy

[weymouth399]

And use a socket or box end wrench you will do less damage this way.

Bob W

[1989kawasaki]

Take out the top triple tree bolts, it clamps down on the fork caps.
DoldGuy

i tried that.. the wrench just spins around the cap