05-06 Marzocci valve specs

[G520]

Thanks KTMLew.

You obviously have studied suspension a lot. Do you know of a web site, or a book where the basic principals fork tuning are explained?

I ask because I now ride in a new area where there are a lot of rocks and loose trail junk. My husky’s WR250 shock is fine, but the forks need to be soften up a bit.
(I know the sensible thing is to send the forks to a professional, but I enjoy to learn stuff and do my own work)

[pobit]

I had another set of 06 DE250 forks appart today for a seal change. This is the 3rd set I have taken apart and so far all the bushings and uppers tubes looked like new. That said, I ground the upper tubes anyhow so the bushings can float even though it does not appear to be a wear problem but may help my other issue which is a harsh feel when under a load. I did ride a different set of forks at the WUDI with the ground tubes and could not feel any difference from the stockers. I also tried removing the bleed shim from the face of the base valve and replacing the first 11x20 crossover with an 11x10. The result was a firmer ride but still suffered from a harsh feel any time the fork was under a load. I had an extra set of stock 06 base valves with me so I screwed those in and they worked better in the rocks but still had a harsh feel especially under a load. So far with my limited test time, I can't say grinding the tubes has made a detectable difference. Here is a picture of the rebound stack used for 06. Note the valve has a 1mm bleed hole in one port similar to the base valve. Also the 21mm rebound face shim does not completely cover the ports either allowing more bleed. There is also a bleed shim on the check plate. Anyone have a rebound stack they would like to share? Thanks, Dave

[GMP]

Thats bizzare. Thanks for the update. They feel like they pack even with all that bleed? Les told me that many of the shims were greater than .1mm thick. Once its straightened out its fine.

[snakey]

could anyone give me a suspension man in in nw england who could revalve my forks cheers snakey.

[GMP]

FWIW, I have a couple rides on my '07 (Zoke/Sachs). There is no harsh feeling related to fork position or load. Its actually pretty good, better than I expected for a stock setup. Even in the rocks its decent and does not deflect. My WPs needed a lot of work to feel like these stock Zokes. I did not have the forks apart yet, but I'm sure they can be even better and have more potential than the WPs.

[motorhead]

Holy cow you guys must be really picky!I loved the forks on my 00' husky wr250 (45 zokes) after I went up one on the spring rate/played with oil level as I changed the seals 700 times.And now on my 05' DE300 gas gas I love em' even more after I got my rear sag set and back'd off the clickers pretty much all the way comp. and rebound.Plush yet progressive and not a leaking fork seal yet!The only drawback i've encountered is a tendencey for my right side rebound adjuster to for some reason back itself out over a period of time???Any ideas on that?Oh yeah, I'm @ 225 without gear enduro open B rider, have not had forks apart yet=stock springs.

[GMP]

Tore my '07 Zokes down tonight to go out to LTR along with the Sachs for revalve. Forks have 10 hours on them. No tight spots. I was also shocked at how perfectly clean the oil came out. I was expecting some debri since they were new and went through break in. This tells me that the bushing debate is a non issue on my forks. Any scraping/binding would surely foul the oil on new, tight components. I didn't pull the stack apart but through a magnifier it looks like pobit's '06 stack.

[pobit]

Sorry about not getting back to everyone sooner but testing suspension is a very slow process. This is what I can tell you so far. Two things I have noticed are causing what feels like a spike in the fork. The first is if the rebound is set too loose on the rear shock the back end will kick and pitch you forward and it feels like a harsh spot in the forks. Part of this is due to the long shock on the GasGas so you tend to feel it more when going down hills or stopping fast in braking bumps. KTM's also have this same problem so I knew what to look for when I noticed it. On my 06 DE300 with the stock valving and a 5.2 spring and 105mm of sag, the rebound adjuster needed to be in the 15 range. It's very touchy so keep increasing the shock rebound until you feel the fork get smoother. As a side note this also helped the rear end track straighter when accelerating out of bumpy turns. More rebound on the rear end will make the shock feel stiffer when riding slow but get up to a race pace and it feels smoother and helps the bike stay level in fast sweepers. The second problem is what feels like a spike in the fork when your deep in the travel. I tried many different compression valve stacks, springs and oil heights and could not get good results. What I found is the spike is not caused by compression but is caused by the rebound being too light. When the fork is deep in the stroke, the fork releases too fast and hits you in the hands and it feels like a spike. The problem is with the high speed rebound so turning the adjuster screw in only makes the fork pack on small stuff yet is still too fast when deeper in the stroke. Last week I tried a stiffer rebound stack and finally made some progress. If anyone else has been down this road and has a good rebound stack they would like to share, it would save me countless hours of testing. Thanks, Dave

[GMP]

Good points. Les told me the same thing about the rebound control. I heard of some guys shortining the shock. What may be an eaiser thing to try for an experiment is the 124mm pull rods. I ran them on my '00 that had an even longer shock.

[pobit]

I tried a set of 123mm and 124mm pull rods. They do lower the rear of the bike and make the first part of the travel softer. The down side was they also caused the linkage to ramp up too fast. At faster speed it went from soft to instant hard and no combination of springs or preload I tried would remedy the problem. The other thing I did not like was the bike would see-saw and was unstable in whoops or rolling turns. Under power exiting turns, the bike would squat and again, cause the bike to lose its line. The best set up I have found so far is the stock rods with more rebound. I have a 2mm and a 3mm shock spacer from MX Tech I may try but I don't want to mess with the shock too much until I am sure I have the fork right. I should point out that the suspension settings I am working on are for racing and not trail riding. My son rides AA and I ride A class. The pull rods did work good at slow speeds at a casual pace. In a nut shell, they made the bike handle like a Yamaha ttr or a Honda XR trail bike: Great when going slow and easy to overwhelm when going fast. Dave