Dec 16, 2000
I have a stock 1991 kdx200 and i'm 5'11 and 195 punds
My front suspension is extremely soft....if i hit small whoops or a rock in the trails my forks practically bottom out. not quite that bad, but i think it would be better if i stiffened up the suspension a little bit. I was thinking about getting 21# or 22# springs...but i'm not sure which is better or if that is the best thing to do. Also, i don't really know what kind of fork oil to get. Is there any other thing i can do to make my forks stiffer without spending alot of $$
any responses would be appreciated....thanks alot!! Matt


Oct 14, 1999
Short answer: Yes

Slightly longer answer:

Yep...21/22# springs would be a better 'balance' for your weight. Which spec depends on your preference, how you ride, etc.

As far as 'stiffer' careful with adjectives in this case. Words like 'stiff' and 'harsh' and 'strong' are sometimes misapplied to the valving/spring setups.

In your case, you could 'stiffen' the suspension by either changing the oil weight, or the oil level. Both of which by the way would be masking the real issue...which is you likely REALLY need a higher rated spring AND some valve work.

Not specifically for the '91..but whatever the oil level in the forks is (say 100mm for example), you will increase the 'firmness' of the forks if you raise that level (more oil). Raise it 10mm at a time until you get to where you want.

5W oil is generally stock. In your case, I'm sure the oil's been changed from that (I hope!!) seeing as the fork oil should be changed every few months. On your next oil change, try a 50/50 mix of 5W/10W. That will firm things up some, too.

Service oil of choice of the masters (like mr. wilkey) for home maintenance is Mobil1 ATF. That of course is akin to saying which premix oil is the 'best''ll find there's a slight difference of opinion among riders!!

No, I don't recall the weight of Mobil1..should..but I'm suffering from brain flatulence at the moment...I don't recall...........

Wasn't the short answer better????


Dec 16, 2000
Thanks alot....i'll try messing around with some oil changes in the shocks before i go for the springs...cause i still owe my parents some money for the bike...i dont need to put myself into any bigger debt...especailly since i dont have a summer job lined up yet!

G. Gearloose

Pigment of ur imagination
Jul 24, 2000

After you get that summer job...:D
What canyn sez and..

Your bike likely has .30 springs.
You can call Fredette, he has 'take off' .35 springs for $50, preload and oil recomendations depending upon your #. 0.35 could by too soft for you too, but he will know and set you up to your riding style.

For instance my '91 forks sagged 1.5" static then another 1.5" when I got on it (180# ride-ready) so you must be seeing even more droop.

Both these numbers are 1" now and it behaves much more precisely all-around.

Perhaps you can add .5" preload to fix the static sag, add oil to effectivly raise the rate some, but as canyn said,its not a comprehensive solution and had tradeoffs, but could get you by until you have the cash.

I used the synthetic ATF with these spings, and the combo is markedly better and recomended, but I only have two data points nor am I a racer.
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