Sachs fork valving '10 300

[Bailey28]

OK guys, I am starting to ride in a new area which has lots of limerocks, roots, ruts, and loose baseball to bowling ball sized rocks.

I noticed that the stock '10 Sachs worked great on moto tracks, and faster soft sandy trails and such. In the heavy rocks and roots the front is killing my speed by deflecting and skipping around. Small washboard roots make the front end disconnect from the trail, and sharp hits jar and wear me out.

I believe at this time I would need to go into the fork to change the high speed compression valving and aside from doing this on a KDX I have no other revalve experience.

How hard would this be to accomplish at home? What special tools would I need to do this? I am a tinkerer at heart and would most likely take the forks apart several times to get what I wanted after experimenting.

I already saw that I need a 50mm 10 point wrench for the caps.

Would it be easier just to send them out?

[swazi_matt]

Sounds familiar. I will be keeping an eye o. This thread

Doubt you need the 50 spanner. The fork caps should be only slightly tighter than finger tight (if you remember to loosen the t clamp pinch bolts first!)

[gg3]

Also watching.Get stuck into it & tell us what not to do.

[Bailey28]

Well that answers my question..... nevermind then.

[GMP]

Thats probably not the best fork to learn on. The cartridge apparently does not come apart as easy as Zokes, plus the shims are an odd 7mm ID size. Also, a proper revalve is more than just compression shim swapping. Have a pro like LTR go through it.

[twowheels]

Originally Posted by Bailey28

OK guys, I am starting to ride in a new area which has lots of limerocks, roots, ruts, and loose baseball to bowling ball sized rocks.

I noticed that the stock '10 Sachs worked great on moto tracks, and faster soft sandy trails and such. In the heavy rocks and roots the front is killing my speed by deflecting and skipping around. Small washboard roots make the front end disconnect from the trail, and sharp hits jar and wear me out.

I believe at this time I would need to go into the fork to change the high speed compression valving and aside from doing this on a KDX I have no other revalve experience.

How hard would this be to accomplish at home? What special tools would I need to do this? I am a tinkerer at heart and would most likely take the forks apart several times to get what I wanted after experimenting.

I already saw that I need a 50mm 10 point wrench for the caps.

Would it be easier just to send them out?

I posted a reply but now its gone ... hurumph! Basically what I said is this...

You don't need a 50mm 10 pointer, although they are cool (I had a couple made up). There is a regular hex head in the center of the cap (19 or 21mm IIRC).

You can do the job somewhat easily without ever removing the caps though. Turn the fork leg upside down (right side up for old guys), and carefully remove the compression tap with an impact gun. Why carefully? Because the material and geometry make it seem like the taps are made of room temperature butter.

Cover the open hole and set the legs aside. With good handling you won't even have to adjust oil level (although you should likely change the oil if you haven't yet).

Clamp the compression tap in a vise and carefully remove the shims and piston, making good notes as to size and orientation of all the bits. Adjust the valving as you desire and then reassemble, using a dab of threadlocker and 25 INCH-POUNDS of torque. Reinstall the taps in the fork legs, and its back to the garage to finish up.

I've attached a couple pics of what you might expect to find inside. Like Glenn said though, if you want to get much beyond working with the compression settings you'll end up having to make tools (like I did) to work on these.

The compression tap stripped of the shims and piston looks like this

Laid out on a bench that translates to

Hope this helps.

[bergerhag]

Here is the base valve shimming laid out http://gasgasrider.org/forum/showthread.php?t=7546

I had great success with no revalving on my '10. Solution was to stiffen up rear shock. My setup now is:
4.6 springs, 100mm 7w oil, comp clickers 10 out, rebound 10 out.
rear is ?hlins shock with a 54 spring, hs 1.5 out, ls 10 out, rebound 13 and static sag set to 25 mm. I weigh in at 88kg now, and this setup is super sweet on choppy ground at high speed. For slower, more technichal terrain i change ls comp to 13, same with fork comp, 13 out. I have noticed that the Sachs forks love to build up air pressure, after a 2h race it sounds like i am emtying my wheels when i open the fork bleeders. This excessive buildup is unbalancing the suspension and makes it feel harsh. I really need to install pushbutton fork bleeders.

[Bailey28]

Sweet, thanks guys... Steve, your pics didn't show up, says they were deleted.


I am a good mechanic and can fix a wide variety of things on the bike, cars, house, etc. I just need an understanding of "how it works" before I get into it and start so please forgive any seemingly overly basic questions on this.

Is removing the base valve and changing the shim stack down there going to affect any of the high speed compression? Or only the low speed? I am quite happy with where the bike rides in the stroke now and the balance between the overall front to rear feeling. I can corner well, and the bike is stable. I just wanted the HS damping charachteristics a little softer on sharp hits without changing much else on the fork.

Years ago, a suspension tuner who revalved a set of YZ forks told me while I watched him do it "You want the suspension resistant to move, but once it starts moving, let it move". I guess he was talking about having the springs and LS compression stiff enough to hold the bike up and control movement over smooth and rolling ground, but on sharp hits, let the fork move to absorb the shock load.

Again, I appreciate the input and if it is not too difficult to do, I would not mind playing with it a little to get the feel I am after.

[Bailey28]

So the diagram here:

http://www.husaberg.org/modules/gall...BaseValve2.jpg

refers to a two stage stack, as what Bergerhag found in his Sachs fork?

From Bergerhag: Ok, now I have investigated the factory settings of the fork. I was surprised to find 140mm oil level, and a light 2-stage compression stack.

Stack:
24x.15 LS
12x.15 LS crossover to HS

20x.15 HS
16x.15 |
14x.15 |
12x.15 HS

10x.30 Collar?
10x.30

comp piston has two large channels for the compression flow, with two 1 mm-bleed holes.
----------------------------------------------------------------------------------------------------------------------

Do I have it right that the HS stack starts "under" the first 24 and 12mm shims?

If this is correct, could I play with the HS stack, maybe remove either the 14 or 12mm shim then reassemble and try it?

Again, for those of you who have been in there a hundred times, any suggestions would be great. I tinker all the time and aside from a near perfect bike, this is the only area that I thought needed some smoothing out.

[twowheels]

Originally Posted by Bailey28

So the diagram here:

http://www.husaberg.org/modules/gall...BaseValve2.jpg

refers to a two stage stack, as what Bergerhag found in his Sachs fork?

From Bergerhag: Ok, now I have investigated the factory settings of the fork. I was surprised to find 140mm oil level, and a light 2-stage compression stack.

Stack:
24x.15 LS
12x.15 LS crossover to HS

20x.15 HS
16x.15 |
14x.15 |
12x.15 HS

10x.30 Collar?
10x.30

comp piston has two large channels for the compression flow, with two 1 mm-bleed holes.
----------------------------------------------------------------------------------------------------------------------

Do I have it right that the HS stack starts "under" the first 24 and 12mm shims?

If this is correct, could I play with the HS stack, maybe remove either the 14 or 12mm shim then reassemble and try it?

Again, for those of you who have been in there a hundred times, any suggestions would be great. I tinker all the time and aside from a near perfect bike, this is the only area that I thought needed some smoothing out.

You could remove either the 12 or 14. If you are particularly sensitive to these things and have a consistent test surface and protocol you could experiment with removing the 12 but leaving the 14, then removing the 14 and leaving the 12.