It's a low speed bleed to bypass a shimstack in the base valve. Totally different animal than the RC3 sh*t.
2010 Marzocchi 888 Evo tuning thread
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where can i order this different shims?
Marzocchi (well at least Marzocchi USA) will be offering a full shim kit. Not sure if they offer that through dealers or have any retailers stock it however.
www.racingsuspensionproducts.com sells shims
has anyone had a chance to get any trail time on one of these forks? Even though my 888 evo is all but purchased I'd still like to hear about it, one of my problems with my 888ata of last season was not only the ata (which like most had a tendency to wind down) but the compression adjustment and the difficulty in finding that sweet spot between clicks of compression, air pressure (which would change depending on the status of the current o-ring that was in there) etc....
Been getting lots of trail time on mine. You can run the compression pretty far in without it getting harsh on the trail. Completely different damper than they've had in the past.
Haven't even touched anything on the fork yet besides adjusters. Not sure what I'd want out of a revalve yet, if anything.
It has been said that the gold knob on the bottom controls is a low speed bleed to bypass the shimstack in the base valve. Now, I have been wondering... what does a base shimstack do? Does it take care of the high speed region of compression or fiddling with it adjusts the range of the low speed region?
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Base valve shim stack covers entire speed range when needle is closed. The fact that it is the base valve and not the mid valve simply means that each shim has less effect on the amount of compression damping, as the ratio (similar to a brake master/slave ratio) of rod movement to oil displaced is quite high.
Due to this very high ratio, you may notice a tiny amount of slop in the stroke, where compression valving on the mid-valve would add an immediate firmness that you can't get on the base without it being harsh. I tried it on my 36, but couldn't stop the cavitation which will occur without pressurization.
It's the same system every fork and shock manufacturer (except DB and Vivid) uses. The shape of the base shim stack can be made to have most effect over any particular speed region. EG: Flat=Lots of low speed with linear progression; Christmas tree=harder progression, ect.
Due to this very high ratio, you may notice a tiny amount of slop in the stroke, where compression valving on the mid-valve would add an immediate firmness that you can't get on the base without it being harsh. I tried it on my 36, but couldn't stop the cavitation which will occur without pressurization.
It's the same system every fork and shock manufacturer (except DB and Vivid) uses. The shape of the base shim stack can be made to have most effect over any particular speed region. EG: Flat=Lots of low speed with linear progression; Christmas tree=harder progression, ect.
Well, I have been lucky enough to get the 888rc3evo ti. Unfortunately I wasn't able to weigh it, as I didn't have scales with an appropriate range. But I strongly believe that it is close to 3kg as Zoke says.
Before mounting the fork on to my bike I took it apart to check the amount of oil and grease and to satisfy my general curiosity
. Oil volumes were just as Zoke recommends, there was plenty of grease on the seals. There is a new foam ring under the dust viper similar to what fox and Rs are using in their forks. As far as I remember most of the parts in the fork are anodized and generally well made - high quality, no plastic crap anywhere...
Can't really comment on performance yet, but initial impressions are great. Fork is very smooth out of the box, I have been on it only 4 days in quite cold weather conditions (where my friends boxxer team was well frozen and he was getting like 10cm of travel ) fork was still behaving pretty decent, there is enough support from new damping so the fork doesn't blow through it's travel as much my 888rc2x did and yet I don't feel that it lost any of it's suppleness and it is noticeably stiffer. So in short it's stiff, well built, with good weight and a high end fork. We shall see how it holds up but I do have a lot of faith in it. Can't wait for the summer.
Back to your post. So you are saying that if I want more LSC I need to cut down the Christmas tree and make it all flat? What an industrialist way of thinking.
Replacing smaller shims visible on the picture with bigger ones or same size as is the biggest one = more LSC ?
Excuse my english it's not my native language...
Before mounting the fork on to my bike I took it apart to check the amount of oil and grease and to satisfy my general curiosity
. Oil volumes were just as Zoke recommends, there was plenty of grease on the seals. There is a new foam ring under the dust viper similar to what fox and Rs are using in their forks. As far as I remember most of the parts in the fork are anodized and generally well made - high quality, no plastic crap anywhere... Can't really comment on performance yet, but initial impressions are great. Fork is very smooth out of the box, I have been on it only 4 days in quite cold weather conditions (where my friends boxxer team was well frozen and he was getting like 10cm of travel
) fork was still behaving pretty decent, there is enough support from new damping so the fork doesn't blow through it's travel as much my 888rc2x did and yet I don't feel that it lost any of it's suppleness and it is noticeably stiffer. So in short it's stiff, well built, with good weight and a high end fork. We shall see how it holds up but I do have a lot of faith in it. Can't wait for the summer. Back to your post. So you are saying that if I want more LSC I need to cut down the Christmas tree and make it all flat? What an industrialist way of thinking.
Replacing smaller shims visible on the picture with bigger ones or same size as is the biggest one = more LSC ?
Excuse my english it's not my native language...
Changing the shim stack changes the 'knee' on the damping graph, or the threshold between the LSC and HSC. The shape of the curve below the knee is 100% LSC and is not changed by modifications to the shim stack. Adjusting the needle valve is the only way to change the shape of the LSC curve:
The following graph shows the change in overall damper curve via changes to the first shims in the shim stack. You can see, that the curve below the inflection point (knee) is always the same shape...what does change however is the point where the shims open, and the regressive HSC takes over
To stay in the LSC region 'longer' you need to make the shim stack such that it takes more force to open. Stiffer or more large shims next to the piston face are one way to do this.
The further away from the piston face....you are effecting the regression of the HSC curve. If the tapper in shims is agressive (fat short pyramid) the curve will be more regressive. If the shim stack tapers less, the HSC curve will be less regressive in nature.
Images as well as some very good reading from here: http://www.peterverdonedesigns.com/damping.htm
The following graph shows the change in overall damper curve via changes to the first shims in the shim stack. You can see, that the curve below the inflection point (knee) is always the same shape...what does change however is the point where the shims open, and the regressive HSC takes over
To stay in the LSC region 'longer' you need to make the shim stack such that it takes more force to open. Stiffer or more large shims next to the piston face are one way to do this.
The further away from the piston face....you are effecting the regression of the HSC curve. If the tapper in shims is agressive (fat short pyramid) the curve will be more regressive. If the shim stack tapers less, the HSC curve will be less regressive in nature.
Images as well as some very good reading from here: http://www.peterverdonedesigns.com/damping.htm
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Think of it as a "timing switch" for the HS stacks almost. That's crude, but kinda the way it works, especially with an adjuster that has a range from freeflow to fully closed off.
This link might be interesting for all you suspension tuning nerds
http://shimrestackor.com/Code/Sample_Applications/Stack-Config/stack-config.htm
http://shimrestackor.com/Code/Sample_Applications/Stack-Config/stack-config.htm
Thanks for great the post dave and to all other guys too.
I would like to find out more about this particullar case ( rc3 evo).
My theory is : Unless the LSC needle is fully closed, the shim stack controls HS region of compressin and as dilzy said when it is fully closed it covers the entire compression range... What are your thoughts on this guys??
I would like to find out more about this particullar case ( rc3 evo).
My theory is : Unless the LSC needle is fully closed, the shim stack controls HS region of compressin and as dilzy said when it is fully closed it covers the entire compression range... What are your thoughts on this guys??
The shim stack in practice with the needle open around mid way (obviously this depends on the size of the bleed hole) will cover a range from upper LS all the way up. On forks where there is a spring backing the stack, the spring controls high, stack mids and needle low. Personally I like to have the stack such that I have the needle closed off to let the shims do all the work.
I had the 40 on my gemini dh; got rid of that bike but kept it for my sx trail which was my everything bike. It was too much fork for that bike, so I swapped it for a 36. Got a Peeler that had boxxer teams (they were noodles) then got my demo with 888 wc's.
I like not having to do the seals all the time on the 888's, but the 40 was a better fork. I'm definitely looking at these new 888 evos.
I like not having to do the seals all the time on the 888's, but the 40 was a better fork. I'm definitely looking at these new 888 evos.
called Zokes bout my warranty issues on my 888 ATA and they gave me a option to change it to a coil for free or buy a new Evo or Evo Ti for the cheap.....decisions decisions.
IH8Rice: I wouldn't change it to coil, you will end up with quite heavy fork. You can coun't with at least 3.6kg (probably even more). Buying new one seems to be better option, especialy with that deal you mentioned. With evo ti weight savings are around 450g comparing to standard version. So if have some spare cash go for Ti version. That's what I did anyways
yeah thats what i was thinking. the 2008 888 ATA's are around 3/4lb more than the new Ti version, plus the new model has a different damping system right?IH8Rice: I wouldn't change it to coil, you will end up with quite heavy fork. You can coun't with at least 3.6kg (probably even more). Buying new one seems to be better option, especialy with that deal you mentioned. With evo ti weight savings are around 450g comparing to standard version. So if have some spare cash go for Ti version. That's what I did anyways
anyone know what weight range the firm spring is for the Evo Ti?
does anyone here have a comparison to a boxxer WC/Team 2010
whats better for racing? whats the difference in feel? I'm really interested in the marzoccchi's but i've been on rockshox only so far...
does the ti version have any advantages over the normal one except the weight and maybe the looks?!?
whats better for racing? whats the difference in feel? I'm really interested in the marzoccchi's but i've been on rockshox only so far...
does the ti version have any advantages over the normal one except the weight and maybe the looks?!?
this was discussed in another thread regarding spring weight.
im the same weight as are some other people with the fork and they said they feel the stock Ti spring is fine for our weight. you could bump up in spring rate to get a little bit of a firmer ride some less preload on the spring
http://www.ridemonkey.com/forums/showthread.php?t=227866&page=3&highlight=fork
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Been riding the stiffer spring a little bit now (I'm 170 and ride steep stuff generally so I like the support in front). With the stiffer spring it seems to suffer a bit on really tall rocks and slapdown landings, so I'm thinking about either lightening up the existing base valve stack or making it a heavier 2-stage stack.
Ok I'm looking at getting a 2010 888 WC or a good deal on a 2009 888 WC,
so the question is what one to get and how do the 2009 and 2010 WC compare?
so the question is what one to get and how do the 2009 and 2010 WC compare?
there is no "World Cup" for 2010, just the Evo and Evo Ti (and RCV for OEM.)
the 2009 WC has a different damping system in it from the new model and it also a bit heavier...i think .75lbs. there is also full Ti bolts in the Evo Ti model. the new model also has tapered stancions near the top and a new bushing design
looks like the Evo Ti's wont be in till the 16th of this month....more sitting on my hands waiting for it
Definitely going back to the stock spring and raising the oil levels now that I've ridden the fork a few times. The damper really seems to constrict on big impacts instead of just slowing the motion. Wonder if it could benefit from some porting work.
how much did you say you weigh? you have 1 spring rate up in there now right?
I'm 170. In the previous generation 888's I used the stock spring just fine, which was the same as the stiffer spring I just put in. Honestly it felt sprung correctly but the damping just made it spike and deflect like a mofo even with everything backed out. Checked out an Evo Ti with some adjusted oil levels and the stock spring that did feel a ton better.
im hoping my 220lb ass will be fine with the stock spring
If you're riding somewhere flat it will be fine. There's two guys locally who are riding the stock springs cranked down with some success, but would probably still rather have the stiffer ones.