Thursday, 21 February 2013

Set up: Understanding the Marzocchi 888

The 888 has a lot of adjustments, here is a guide to what everything does. Every adjustment is relative to the spring rate, so get the spring correct and work from here.

Spring options

Titanium k=4.4 " 5141956 - soft k=5,5" 5141918 - med k=6.5" 5141957 - hard k=7.7" 5141958 -  x hard
Steel k=4.4 " 5141959 - soft k=5,4" 5141923 - med k=6.5" 5141960 - hard k=7.7" 5141961 – x hard
preload
Spring Preload
Spring preload can be done with the external RH adjuster on top of the fork. Preloading the spring will compress them slightly and increase the initial force needed to compress the spring. Marzocchi forks can use the maximum amount of preload from the adjuster and the fork will still get full travel. Spring preload is used to fine-tune the spring rate to adjust for the proper sag measurement. Minimal spring preload is recommended for better performance and longer working life of the springs, so it is better to change to a stiffer spring rate than to add significant preload (10+ turns.)
Sag refers to how much the fork compresses when the rider is in the normal riding position. Marzocchi recommends 20-30% of DH travel in sag to provide the best overall ride. The easiest way to measure sag is to put a zip tie around the stanchion and then measure how much the fork compresses when the rider is in the normal riding position. Keep in mind that the normal riding position on a DH bike may not be correct on level ground.


rebound


Rebound Damping
Rebound damping controls the rate in which the fork is able to extend. All Marzocchi forks have adjustable rebound damping. Rebound damping should be set fairly fast, but without causing a sudden, harsh force back to the rider. This will allow the fork to comfortably extend to full travel as soon as possible after impact.
The 888’s damping adjuster located on the top of the left hand leg and is anodized red. Turning the adjuster clockwise will slow the rebound speed and therefore turning the adjuster counter-clockwise will speed up rebound.
It is a good idea to get a feel for how the different rebound adjustments affect the fork. Try turning the adjuster all the way counter-clockwise to the fastest rebound setting and then quickly compress and release the suspension several times. Next test the fork with the adjuster turned all the way clockwise and then somewhere in between. This will demonstrate the differences between damping settings.
compression
Compression Damping
Compression damping is the oil flow resistance felt when compressing the fork. Compression damping is categorized in two ways: low speed compression and high-speed compression. Low speed compression refers to when the fork is compressed slowly and gradually, for example during rolling impacts and rounded bumps. High-speed compression refers to the resistance felt during multiple, hard impacts and square-edged bumps.
Too much compression damping creates a harsh ride because the suspension cannot compress rapidly enough to absorb large impacts. Compression damping is not a substitute for proper spring rate and should not be adjusted until the fork has the proper spring set-up for the rider.
Low speed damping is typically used to dial out excessive fork dive or rider induced movement. High speed is typically used to make the forks action more progressive and resist bottoming out.
The compression adjuster on the 888 is located at the base of the LH leg. The RC3 compression adjuster will affect both high and low speed damping, simply put if you set the adjuster all the way to “+” it will give you maximum low speed damping, set the adjuster all the way to “-“ will give you maximum high speed damping.
Both high and low speed damping curves cross in the middle so the adjusters neutral position is in the middle (count the clicks/ turns). Adjusting out from the middle with give you a varying combination of both high and low speed damping, so in theory you have all the combinations of damping you would normally have in two separate adjusters, but in one easy-to-use adjuster.
***graph for visualization purposes only



Volume adj 
Volume Adjust
Volume Adjust is a simple and effective way to control the second half of the compression stroke and is located underneath the rebound adjuter on the top of the LH leg.
The VA works via lowering and raising the top of natural air chamber inside the fork. This gives the same effect as raising or lowering the oil volume; a tuning ‘trick’ often used to make the compression stoke more linear or progressive. The VA offers this with an easy to use external dial. The effect you ‘feel’ is to make the fork more progressive, ideal for larger drops without sacrificing small bump performance.


Note: this following image does not relate to the above feature but relates to a question asked bellow.


46 comments:

  1. This comment has been removed by the author.

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  2. Regarding the compression adjuster, i thought it only adjusted low speed compression. It mentions that in the manual and the website.
    You stated that it adjusts both high and low speed compression, could you please confirm and or explain?

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    Replies
    1. This adjuster is hi and low on one dial with the damping curves crossing in the middle. Adjust to 'Hard' gives you maximum low speed), adjust to 'Soft' gives you no low speed but maximum high speed. Have a play with the settings and you will be able to feel the difference?

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    2. Sorry but this explanation is completely incorrect. It is a low speed adjuster, there is no reduction in high speed damping when you increase the low speed - in fact, like all low speed adjusters, increasing the LS damping very slightly increases the high speed damping too. This can be demonstrated on the dyno.

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    3. ok, to be completely correct the RC3 + EVO model has the hi-lo adjuster, the EVO V2 (2012 +) has low speed compression adjust and high speed compression via the shim stack valve.

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    4. But RC3 EVO also has a shim stack valve?! What you sayin?

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    5. All Evo 888's have the shim stack that can be removed, the pre EVO RC3 had a sealed damper without removable compression valve.

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  3. I have searched high & low & I can't find my answer...

    My fork (888 rc3 evo v2) is leaking out of the rebound & Volume knob. Marzocchi want's me to send it in or get a rebuild kit with the part in it. The service guy I just talked to said I needed to take off "the worlds smallest snap ring" to get to the spot where there is a forgotten shim. I have had the fork apart myself and got the top cap off the cartridge but I can not get an answer on where this missing piece is supposed to go. The C clip holding the cartridge to the top cap isn't THAT small so I don't think that's what the service guy was talking about. It's not pbvious to me that the red anodized cartridge comes apart easily so I haven't gotten into that yet... The exploded diagrams all leave the top cap attached to the cartridge & don't show what's underneath it.

    I stacked a few aluminum can "shims" under the c clip that is just under the silver volume knob and that helped stem the leak for a few runs but it now continues to leak out when upside down and when ridden. Do I just need to more shims there? Everyone is hinting that this is a known issue but I CANNOT get anyone to tell me what exactly I need. If I can save the time and $40 of the rebuild kit by using a 10¢ o ring I would like to know...

    Any help at all is appreciated.

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  4. the top part is assembled, stop ring, washer (shim), o-ring then top plug. either the o-ring is torn or there is to much movement between the plug and cir-clip. To remove play we use shims used in damping circuits as these are very thin (0.1mm).
    Honestly, we have not had this issue in the UK, but to remedy all we would do is replace the o-ring (as a precautionary measure) then use an assembly grease on the o-ring (not a lube grease. I cannot attach an image in this text box so I have added an image of the parts broken down in the main body.

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    1. Major help. Thanks a ton. I thought that shim was pressed on as it did not come off during my multiple tear downs. The o-ring beneath it was missing. I'm lucky to have a huge assortment of o-rings in my garage so I found one that fit and went for a ride. Seems fixed. Going to put some assembly grease on it as well for good measure later on.

      So glad I didn't spend $80 for my LBS to tell me I needed a 10¢ o-ring. Thanks Again.

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  5. I have tried to fit my 2011 Ti spring in my 2013 RC3 Evo V.2 fork.
    The 2011 Ti spring is somehow wider and it did dot fit to the plastic part at the bottom of it. is it ok to use the 2011 Spring like this or I have to change any other parts at the Spring side?
    By the way, I thought that the only update betwenn the 2011 and 2012 models was the cartrige. The Coil side is totally different though. It is thinner and this small coild is 3x bigger than the 2011 one. Is that a change to avoid bottoming out?
    I say that because with my 2011 Fork I had constantly this problem.

    Thanks
    Cristiano

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  6. hallo there!!!

    what weight range is the soft k=5,5" ti spring, ideal for?

    i weigh 185lb.

    Kind regards
    George

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    Replies
    1. it vastly depends on your riding style and personal preference as a lot of adjustment can be made on the fork. However if you are quick and you race, I would suggest going to hard for your weight.

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  7. thank you!!!!

    1.what is the max weight for the 5.5 spring?

    2. You stated that the compression adjuster adjusts both high and low speed compression, but in the manual it says that the high speed is only adjusted via shim stack. are you sure???

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    Replies
    1. As I said, the spring rate depends on your riding style and preference, if you are happy with it then its ok.
      The compression adjuster is the biggest miss-understood feature of this fork, it offers high and low speed compression - I have added a graph so you can visualise how it works.

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  8. thank you!!!\

    a few more questions:

    1. should i add oil in the spring side or in the damper side, to have mopre progression the whole travel?

    2. more oil or heavier weight oil? (instead of 7.5, to put a 10wt oil)

    3. what do you suggest in order to improve mid travel support (to sit high in the travel)?

    you are correct about the compression adjuster, i had 7 clicks to hard, and it was so much better in performance!!!

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  9. Hi..Dan nice blog...I like that blog very much which make understand by images.So thanks for sharing this nice post.
    compression springs"

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  10. Hi I have RC3 Evo 2 2012 and when it goes in compresion there is a little bump noise which is Coming from Rebound steem as it starts filling with oil. any ideas how can I eliminate this problem ?

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  11. Hi Jaryn, I think you probably have just a very hard low-speed compression setting and the noise is just the shim. I would probably just suggest a simple refresh by changing the oil for a high quality motorcycle type?

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  12. Great blog, I really liked it. I found all the information very useful.Thanks for sharing the post.. air tools

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  13. HOLA PUEDO PONER A UN FORK 888 RC3 EVO V 2 UN SPRING DE TITANIUM???

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  14. About compression damping, if I understand it correctly e.g. when we ride at pumptrack its better to set adjuster to + (hard), when we doing drops its better to set adjuster to - (soft)?

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  15. Hi,
    last day I tired to service my 888RCV form the year 2012, but it failed. I looked at all the components of the fork inside the bike and changed oil, but now the rebound doesn´t work.

    Does somebody knows what could be wrong?
    D

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    Replies
    1. did you use the correct oil? Is the adjuster 'stuck' open?

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    2. yes of course,
      i used a 7,5w motul oil

      there´s no difference if the adjuster is open or closed :(

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    3. you will need to get the rod out to check the function of the adjuster?

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    4. i also thought that the problem could be there, but i already checkt it.

      When i turn the adjuster, the shaft turns and the hole at the top of the rod closes, or opens.

      Probably i assembled the parts in a wrong way...

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  16. Hello, I'm looking for a tutorial on how install springs on a 06 888. Thanks!

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  17. Hello, Dan.
    I have a 88 Rc3 evo2 2014, and is leaking out of the compression knob, i changed the o-ring and continues leaking.

    Any help at all is appreciated.
    Thanks

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    Replies
    1. I think you will need to replace the complete compression unit, part 726036/P

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    2. Hello..can you tell me how to open the compression from the catridge..i think there's o ring inside that..tks

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  18. Hi, do you have a tutorial for the 55RC3ti Evo V2? Or know anywhere I can find one?

    I want to know how to top up the oil levels a tad

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  19. Hi I have a 2013 888cr and am trying to change the oil after I removed the dampener and replaced oil it seems to be air bound how do I bleed it

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  20. Hi. Hope people are still active here. I've got a Marz 888 RC3 Evo V2 2012. When I took the fork off the bike, removing it from the crowns, the rebound/ compression leg sags lower than the spring leg. Do you think this might just be a lack of oil or air? Hope someone can answer. Thanks.

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    Replies
    1. this is perfectly normal as this le does not have a spring in it!

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  21. Hey, I'm glad it looks like you still respond! Finally serviced my trusty 66 rc3 ti. Everything went smoothly except installing the golden compression adjuster knob.

    Mine is a 2012, and instead of a set screw, they used a rubber O-ring in a notch that goes right between the fork nut and the comp adjuster knob. When I try to slide the compression nob down on the nut, it just pushes the O-ring down instead of seating it where its supposed to.

    There's gotta be some stupid trick to this haha

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    Replies
    1. try some grease on the nut, so the o-ring slides rather than rolls?

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  22. Hello

    i lost small oring of RC3 cup. could someone help me and give me right measures?

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  23. Hi Dan, love your blog! I just serviced my 888 RC3 EVO V.2 (2014) last night into this morning and should've taken a nap in the process (never work tired). I seemed to have blanked out like a school girl because my fork is miraculously fully assembled but feels like sh!t! Harsh immediate compression, feels ok mid stroke. Here's what sleepy me remembers:

    During end stage re-assembly - with fresh fluid in the compression/rebound side and top cap installed - I turned the fork upside down, gently opened the compression knob on the bottom and let out the air (while compressing the leg to get that air out). The leg now has a vacuum chamber and wants to compress on its own and resists hard when I pull up on the stanchion. Far more than be before I opened it. Is it safe to assume I should've left the air in that chamber?

    Also, I noticed what looked like either light grease or oil sludge inside the plastic wrap of the spring and along the rods... is that sludge buildup? I had the fork new and this is the first service (I don't ride as much as I'd like to).

    That plastic shrink wrap is shredding apart... is it safe to remove it completely and should I replace the wrap with something around the spring?

    Lastly... in the image of the cartridge on top with the top cap disassembled, you have in order: top cap, o-ring, metal washer (shim stack?) then C-clip. .. is that the proper assembly order? Does that rubber o-ring go right on the top cap and the metal washer compress it into place and then held in place by the c-clip? I did that. But i have 2 metal washers instead of 1 from factor. .. should i be running one?

    Ok that was a novel and i do apologize for the length of it. If you would kindy respond or direct me to a place where i can source the info I'd greatly appreciate it.

    P.S. is there an assembly diagram (break down) of the fork internally? Can't seem to find one online.

    ReplyDelete
  24. Hi Dan, love your blog! I just serviced my 888 RC3 EVO V.2 (2014) last night into this morning and should've taken a nap in the process (never work tired). I seemed to have blanked out like a school girl because my fork is miraculously fully assembled but feels like sh!t! Harsh immediate compression, feels ok mid stroke. Here's what sleepy me remembers:

    During end stage re-assembly - with fresh fluid in the compression/rebound side and top cap installed - I turned the fork upside down, gently opened the compression knob on the bottom and let out the air (while compressing the leg to get that air out). The leg now has a vacuum chamber and wants to compress on its own and resists hard when I pull up on the stanchion. Far more than be before I opened it. Is it safe to assume I should've left the air in that chamber?

    Also, I noticed what looked like either light grease or oil sludge inside the plastic wrap of the spring and along the rods... is that sludge buildup? I had the fork new and this is the first service (I don't ride as much as I'd like to).

    That plastic shrink wrap is shredding apart... is it safe to remove it completely and should I replace the wrap with something around the spring?

    Lastly... in the image of the cartridge on top with the top cap disassembled, you have in order: top cap, o-ring, metal washer (shim stack?) then C-clip. .. is that the proper assembly order? Does that rubber o-ring go right on the top cap and the metal washer compress it into place and then held in place by the c-clip? I did that. But i have 2 metal washers instead of 1 from factor. .. should i be running one?

    Ok that was a novel and i do apologize for the length of it. If you would kindy respond or direct me to a place where i can source the info I'd greatly appreciate it.

    P.S. is there an assembly diagram (break down) of the fork internally? Can't seem to find one online.

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  25. Hello..do you know how to open compression from the catridge.?not the knop..

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    Replies
    1. only the Evo can be opened and the evo unit un-screws from the base of the damper, see the diagram used in the blog header.

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  26. Hello just did a basic oil service on some 888. Everything worked fine before service but after the air volume doesn't seem to be working. The dial doesn't have any clicks in it when you turn it and it doesn't feel to have any effect on the fork....Any ideas muchly appreciated.
    Cheers
    Mick

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  27. Hello, hoping you still check on this post. I bought a 2013 rc3 evo v2 ti, which was topping out in the last 1-1.5 innches of travel, I thought this would be due to low oil levels in damper, but having changed the oil and put the recommended 325ml, the problem continues. I've tried even higher oil levels but it seems like the damper won't fill up. Rebound works fine for 90% of the travel and then just shoots out the last 10. cycling the fork intensely works sometimes and lasts a little while, but the problem pops up even while riding as if there were an air bubble at the top of the damper that wont go out. What could be wrong with the damper and which area of it should I be looking at to see what the problem is?
    Thanks,
    Robi

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