KDXRIDER.NET

I've been adjusting my bike's suspension lately:
-ATF, .40 springs, 5mm PVC Spacers (forks)
-Set 4in of sag to my weight.

The bike sags down so much now that the kick stand won't work! Has any one had this expierence? I think I should get a lighter rear spring but I can't help feeling the forks 5mm spacers are not enough. Any help would be appreciated and I know I've had alot of posts to do with suspension because I've never done this.

free sag on the rear of the bike should be about 30mm. With the rider in full race gear, sitting or standing on the bike in the attack-type riding position and a buddy supporting you from falling over, the sag should be about 100+ mm.

The kick stand is not designed to support the rider on the bike when deployed.

SHOCK
Besure that when you note the "initial length" between the axle and upper frame that you are extending the shock. You do this by pulling UP on the frame in the area of the rear fender while taking the measurement.

PS You may be chasing you tail if you are just trying to get race sag number by measuring the difference in height between frame and axle - then re-adjusting the shock preload - and remeasuring the frame to axle distance. i.e. Need to base race sag number ~95mm from the fully extended position which means lifting up the rear of the bike to extend the shock.

FORKS
Are 5mm spacers the correct preload spacer for your bike forks? Likely not.

When we talk about 5 - 10 mm of preload for the springs we are talking about also measuring the available space for the spring (fully extended rebound rod): taking up the excess space with spacer material and THEN adding the additional 5 -10mm in spacer length to get the spring preload.

Hope this helps.

She needs a service my man!

IdahoCharley wrote:FORKS
Are 5mm spacers the correct preload spacer for your bike forks? Likely not.

When we talk about 5 - 10 mm of preload for the springs we are talking about also measuring the available space for the spring (fully extended rebound rod): taking up the excess space with spacer material and THEN adding the additional 5 -10mm in spacer length to get the spring preload.

Hope this helps.

Yes it does I only put 5 from the get go. Ill try the sag too.

I had the same experience.
With the race sag set at just under 4", my free sag was at 2" and the kick stand didn't want to work.
I've since decided that a free sag number in the neighborhood of 1 1/4" is more important and race sag be what it may. I ended up adjusting my race sag on the trail. I'd run a loop, lay the bike over and spin the spring, run a loop, until I got the "attitude", steering, and action where it worked well.
When I got home I measured the free and race sag for recording purposes.
1 1/4" free sag, 3 3/4" race sag. Go figure.
I think how warmed up the suspension is has something to do with those earlier garage measurements.

KarlP wrote:I had the same experience.
With the race sag set at just under 4", my free sag was at 2" and the kick stand didn't want to work.
I've since decided that a free sag number in the neighborhood of 1 1/4" is more important and race sag be what it may. I ended up adjusting my race sag on the trail. I'd run a loop, lay the bike over and spin the spring, run a loop, until I got the "attitude", steering, and action where it worked well.
When I got home I measured the free and race sag for recording purposes.
1 1/4" free sag, 3 3/4" race sag. Go figure.
I think how warmed up the suspension is has something to do with those earlier garage measurements.

If you think your suspension is good now: you should really try one set-up for your weight and working correctly. Bottom Line - 3.75 inch race sag is good but with 1.25 to 2 inchs of race sag something is amiss. Maybe the shock is low on nitrogen, maybe the spring is too stiff for your weight, maybe you have some linkage or swing arm binding going on. (Maybe a combination of one or more of the mentioned factors).

What are you missing? A lot more fun and control I expect!! Not trying to diss you or the bike - just trying to point out if you think its good now - do a little more work in figuring out what is not working and I believe you will be a improved rider. One thing is with that much free sag you will not get the preload spring rebound that most of us like to utilize off of water bar jumps, ditches, etc.

Redid forks- seemed to be the cause of the sudden change.

Rebuilt shock just need to put the nitrogen in (before it was 77psi and the oil was black and like water)

Charlie-
Please read again- I'm at 1.25 inches free sag, or 31 mm and 3.75 race sag or 95.25 mm. I've found that free sag to be more important than race sag, actually.
The point was really that gross adjustments to suspension can be done in the garage, but fine adjustments need to be done after the suspension is up to operating temperature. I wasted a lot of time early on playing with clickers on a cold bike.
I'll make a two click change in compression dampening on the shock and really notice the difference, now.
Two clicks harder, you better go fast!
Two clicks softer, it don't work at all!

My dad couldn't do the nitrogen because the chuck wouldn't fit. Now I have to search for a straight chuck but I have swingarm bearings comming in so I'm outta commission anyway.

KarlP wrote:Charlie-
Please read again- I'm at 1.25 inches free sag, or 31 mm and 3.75 race sag or 95.25 mm. I've found that free sag to be more important than race sag, actually.
The point was really that gross adjustments to suspension can be done in the garage, but fine adjustments need to be done after the suspension is up to operating temperature. I wasted a lot of time early on playing with clickers on a cold bike.
I'll make a two click change in compression dampening on the shock and really notice the difference, now.
Two clicks harder, you better go fast!
Two clicks softer, it don't work at all!

That does sound close for the KDXs. (1.25 free and 3.75 race sag) I was under the impression that the static sag was changing on you; depending upon whether or not the suspension was warm. Changes in either free sag or rider sag should not change whether based upon the shock's temperature. You certainly are correct in that fine tuning is best done on the track or in the woods. Everyone has those own riding style and needs to tune the suspension set-up to their riding style. Now let those ponys run loose and have some fun!!

Nah, the sag doesn't change for temperature, but the action certainly does. It takes about 5-10 minutes of hard going before it is warmed up.
Make no adjustments before then