Marzocchi 48mm CC Forks

Scrambler, I'm about the same (165lb geared up) and have a 250 coming in Feb. Will let you know what I get for springs. On my 2011 I ended up using 4.0 fronts and 5.0 rear (stock was 4.2 and 5.2). I ride tight east coast single track with lots of trail trash and roots. The stock springs may be fine.
 
This new system will most definately increase the user adjustable tuning scope as far as terrain goes, but a spring is a spring and you will need what you have been running before. I suspect there will be more potential to "dial out" an incorrect spring rate which will no doubt screw up the action of the fork and complicate tuning. This adds another dimmension to tuning from the rider's perspective, but when you think about it it has always been there from the tuner's perspective in a standard CC fork.

I know I'm going to need a rate up on each end, was hoping the Race models would come that way.
 
I'm about 210 with gear on.. Rear is now 5.4 which is still soft for me. Front is standard 4.2 and it's also too soft for me but i added some oil to outer chamber to stiffen end of the stroke and with pfp i can play the mid stroke pretty well - so i'm in no hurry to get stiffer front springs.
After winter i will change to 5.6 at rear as there i feel the need much more clearly.. Riding in snow: soft suspension is good!

-Mika
 
I'm confused about the 2011 Race xc250. Some people say they come with Marz 45's and others say they come with the Marz 48's. Can someone clarify what actually comes on the 2011 Race xc250, and just how good or bad they are compared to the standard model ec?
 
They come with the 48s in the USA. I think some of the confusion about this is there are people here from all over the world discussing bikes in those markets without specifying them.
 
I rode a set of stock EC race 48mm CC zokes back to back with my semi revalved 45mm OC zokes. The 48s were much better at dealing with g outs, and higher speed hits, I found them about the same at dealing with trail trash, they didn't blow through the stroke on bigger hits and didn't transfer harshness back to the bars as much as the 45s. They were probably still a bit stiff for my tiny 65kg, but I could have easily raced them with confidence.
 
48mm Oil Change

I'm planning to dump the oil out of my outer chamber and refill with about 30cc less with 5wt to cheaply soften up my forks a bit. Can anyone confirm I can just loosen the top cap, slide down the outer tube and dump the oil? I'm a suspension novice, and don't want to break anything expensive.
 
rxmx said:
I'm planning to dump the oil out of my outer chamber and refill with about 30cc less with 5wt to cheaply soften up my forks a bit. Can anyone confirm I can just loosen the top cap, slide down the outer tube and dump the oil?
Click to expand...

Sure, you can loosen the cap, dump the outer chamber oil and refill to your spec. You will have to let them drain for a bit to get close to a "zero" measurement, but you'll have to assume you will not get the entire amount of oil out of the fork. This will effect your refill measurement. (In this case assume at least 5-10cc will remain in the fork, regardless of how long they drain, unless they are taken apart and cleaned)

Keep in mind, the outer chamber oil is mostly there for seal/bushing lubrication and the progressive spring force at the end of the stroke. So going lighter on the outer chamber oil wont have the "wow" factor of a cartridge valving change, if softening up is what you really want to achieve in the initial stroke. Lower oil height will help with mid stoke harshness in some cases as long as the spring rate is correct.
 
PFP notes (Updated)

OK, been slammed at the shop with work, but got enough time last week to completely go through the Marzocchi TC (twin chamber) 48's on our '11 250 Race demo bike. As discussed previously, I've been hesitant to change too much before I got a good idea of what I did and didn't like about the fork. Don't get me wrong, not only do I think these forks work great after some minor changes, they have serious potential to get really really good. They just need some TLC (or at least in my case they did) I'll just share some of my experiences, so that others can chime in or see if they too have had the same issues...

Some initial issues I had with the forks:
-Compression clickers have a very faint or non-existent "click" from the adjusters (there should be 6 clicks per turn, 26 total clicks) Mine were barely noticeable on both sides.
-Fork action was harsh on roots, rocks & braking/accel bumps
-Fork action was very quick on rebound, was hard to settle for corners when pushing hard.
-For me the 4.2Nm (.43kg/mm) spring is way to light (I'm 195#) Keep in mind all the new WP forks for the 250/300 Kattoms come with .45 kg/mm springs and 95% never complain.
-Forks had a VERY bad rebound "CLUNK" noise from the front end in hard acceleration chop (ie: sand whoops) Felt like the strg brgs were loose, but weren't (see previous posts)

Initially, over a month ago I simply pulled the cartridge, springs and split the tubs to blueprint the seals, bushings and springs for sizing. My particular forks had different preload btwn left and right legs (5mm difference) It was very evident with the spring seat clip on the cartridge. The seals were also devoid of any seal grease. I greased the seals, reset the spring preload to 5mm (standard) and lowered the oil from 330cc to 310cc. I road this setting for another 300+ hard miles. The fork was maybe 15% better, but still harsh and clunking on hard rebound (Ive been over the some PFP setting issues in previous posts)

Per the issues listed above, here's what was changed/corrected...

-COMP Clickers: disassembled the complete compression assembly, clicker assy and all. Found basically too much grease packed into the ball & spring detent grooves for the "clicks" to be felt. Cleaned out, light grease, compression clickers work great now. Problem solved.

-Checked valving setting with notes from Marzocchi Italy, nothing out of place. There was a large price of rebound piston band jammed into one side rebound valving, which didn't help my rebound issues. Needed a new piston band, so while waiting for my OEM parts shipment I fabbed one from a WP piston band, fit prefect. Problem solved.

-I ditched the stock springs for .45kg/mm set, readjusted the preload with the spring seat clip, ended up with 4mm. The new springs we're stocking for the Marzocchi's fit fit like a glove!

-Surprisingly all four main bushings had a good amount of metal contamination in the teflon already. They were all replaced. A new set of SKF seals were added to match, along with a chrome tube lathe polish.

-Reassembled the forks (STD valving), with OEM spec oil. Took careful notes on the PFP setting relative to cartridge oil fill procedure. Reset oil height back to stock 330cc, clicker base at C20 R15 PFP 2 Trurns. (I know the standard rebound setting is R20, but they are just too fast for my taste)

Went out and pounded some hard NJ sand trails. Damn, forks are like butter on everything. Harshness gone, even better on g-outs, and still turns like a champ. Let a few others ride, they were equally impressed in the improvement. And BEST yet, the F*ING CLUNK is gone! I still think the rebound circuit needs to be slowed down internally, but more on that later.

I'm very pleased with what a simple service and spring change did to the fork performance. I think anyone who's got fork issues just needs to get a proper fork service and spring rate swap for their weight before ANY valving changes are made. These forks have huge potential, don't get frustrated, just get em serviced.

We're stocking complete springs, bushings, seals & oil for the TC fork. If you guys need anything, call the shop I'll be more than happy to help out. Our testing will continue each weekend, I'll post more as it comes...

Note: the cartridge CANNOT be assembled like a normal KYB or Showa fork to set the PFP spring preload correctly, this is critical to eliminating the dreaded "rebound clunk"
 
I need a little help here. I picked up my new 2011 250 Race today, and I'm checking it over before I break it in.

I can't locate the PFP or the spring preload adjuster. The pictures in the manual are only for the 45's not the 48's.

Pictures would be great, but a little more explanation would be appreciated also.

This is a great web-sight and I've already learned a lot about my new ride. Thanks for sharing.

I'll post a comparison to my KTM 250xcw when I get some seat time.
 
It is a preload adjuster, but for the CC chamber spring, not the main fork spring. Check with the owners but this is what was discussed.
 
For the riding you're doing you'll likely want to back the PFP adjuster out to zero from the stock two turn setting.

The owner's manual won't be very helpful (shocked ... SHOCKED) but your dealer should have given you at least some insight into the adjustments. Good thing this board, and particularly this thread exists.
 
Here's a picture of the top of the fork. The center screw is the compression adjustment, the phillips screw is the air bleeder, so I assume that the star shape is supposed to be the PFP. However, the star piece does not turn? Any advice?
 

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singletracker said:
Here's a picture of the top of the fork. The center screw is the compression adjustment, the phillips screw is the air bleeder, so I assume that the star shape is supposed to be the PFP. However, the star piece does not turn? Any advice?
Click to expand...

Won't turn by your fingers or won't turn with a wrench? A good six-pointer should fit right on. Remember you're pre-loading a relatively stiff spring.
 
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