DRZ drz 125 front forks

Drz 125 front forks bottom out , don't know if oil has ever been changed . What oil should be used ? I'm 5'5 160# bike is 2007 . Almost all stock , used for light motorcross , and trail riding . Any suggestions , change springs ?? Something else I should know ???
 
Those bikes are inherently under sprung, I'd check around for heavier springs in the aftermarket world. The viscosity of the oil concerns the action of the forks but does not help with bottoming issues.
 
If you can't find any springs you can shorten the older ones and make a spacer the same length as your cut out section to keep the preload. Drill the caps and thread in some Schrader valves so you can add from 3-25 lbs of air or a combination of both. Just depends on what you want to spend.
 

SRAD97750

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I like the idea of the air ride , I can drill and tap for schrader valves , will it affect dampening ????

it will make the forks return faster, much like a heavier spring will.

I don't pay a whole lot of attention to the manuals on the amount of fork oil, since they are not always the same from side to side. that can be due to one side draining out more than the other etc. I start them all at 5 inches from the top of the tube (measured from the "short side", or side closest to the rider), without springs. Next I extend the forks and make sure that the damper rods (in your fork's case) are covered. In go the springs. Now you can ride it and add oil if necessary. Some of my old damper rod forks were as high as 3 inches from the top. you get a certain amount of bottoming resistance from that alone, since the compression space is smaller.

For you , I would start at 5, make sure the levels are equal. do the drilling and tapping. you can get some really nice compact line that air brake equipped trucks use as control line and set the forks up with an elbow and a t, which will allow you to fill from one side, and keep the pressures equal. clever routing can keep it all behind the number plate/light if you want.

Try and remember the surprisingly low pay we get for dispensing what most of us learned by lots of time investment, not to mention money. (Manuals are pretty easily obtained online fyi.)
 
Thank you ! That is a lot of help . Did some digging and now have downloaded manuals for all of my bikes . i figure that one fitting on each fork will do , and a low pressure gauge to check will be the cheapest way . I understand that education is best learned from experience but manuals do help . I hope I can give my grandsons the help they deserve .Again thanks for your help Bernard ...
 
you are welcome. I have done a lot of one side one valve mods. the biggest problem is from having trouble getting the sides even. I use an air can that i fill up to whatever pressure I want to try to put into the forks. then I just extend them full on the stand and hold the air chuck onto the valve for about a two count, and repeat on the other side. Don't try it with a tank that is more than 40 lbs is my suggestion, as it only takes a second to over fill them. I used to see guys do that off a compressor and tank, back when lots of us were running air only springless conversions. You start blowing seals out and it only takes a second. 90-100 lbs comes up really fast. So i would never suggest filling from a gas station. one of those little inflators that goes in your cigarette lighter/power point should work fine though.
 
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