Marzocchi 380 Master Thread

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Marzocchi 380 Master Thread
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flag only1mikey
O+
Posted: May 17, 2016 at 15:32 Quote
One other thing I just looked at and though was interesting.

On my old 2012 Fox 40, I originally ran a green spring (45 inch pounds or 5.0nm) then later switched over to a blue spring (40 inch pounds or 4.5nm) to reduce hand fatigue on long days at the park.

That said, in theory, shouldn't the 5.5nm (48.5 inch pounds) spring feel even stiffer that both (I know first hand it's not).

What am I am missing?
flag henkster
Posted: May 17, 2016 at 17:20 Quote
only1mikey wrote:
One other thing I just looked at and though was interesting.

On my old 2012 Fox 40, I originally ran a green spring (45 inch pounds or 5.0nm) then later switched over to a blue spring (40 inch pounds or 4.5nm) to reduce hand fatigue on long days at the park.

That said, in theory, shouldn't the 5.5nm (48.5 inch pounds) spring feel even stiffer that both (I know first hand it's not).

What am I am missing?

The 5.5nm spring is stiffer than the 5nm, which is stiffer than the 4.5. The things that might affect the perceived stiffness, or the ability of the fork lowers to move up and down are:

- If you fit a 4.5 and dial in all the preload you can then you might make it stiffer than the 5nm
- If you have tons of compression damping then the fork will resist compression
- If you have tons of rebound then the fork will pack down and only move deeper into the spring's travel with more force - once it's partly compressed it becomes stiffer, like with preload
- If there's friction in the fork from no oil/grease then it'll take more to move it
flag smuggly
Posted: May 17, 2016 at 20:32 Quote
frampo wrote:
Just took my forks off the bike and went to move them by hand with no compression and fastest rebound. I couldn't move them. I then put the lowers on the floor and got them to move but sound they got stuck down and didn't return to full travel. I think the bushes are too tight.

They are going back to the uk distributor/marzocchi uk this week to get looked at. This will be the second time they have gone back with a similar issue. Last time they came back with new lowers and stanchions.

I have been emailing steve at vorsprung about my issue and he has suggested getting the bushes resized and that if the distributor are just replacing lowers it may not fix the issue.

Does the axle line up properly when you remove and reinstall it?

I twisted mine in the crowns a couple of months ago, it was only a little bit but the fork was more or less jammed.
flag way2manyhobbies2keep
Posted: May 18, 2016 at 14:53 Quote
only1mikey wrote:
One other thing I just looked at and though was interesting.

On my old 2012 Fox 40, I originally ran a green spring (45 inch pounds or 5.0nm) then later switched over to a blue spring (40 inch pounds or 4.5nm) to reduce hand fatigue on long days at the park.

That said, in theory, shouldn't the 5.5nm (48.5 inch pounds) spring feel even stiffer that both (I know first hand it's not).

What am I am missing?

that's interesting you say that because 2 years ago when I looked all this up I could have sworn I saw way higher springrates on the fox springs.

From experience, fox ti springs fit in the 380 just fine, and the fox blue spring is noticeably stiffer than both the 5.5 and 6.5nm springs, I would put it up there in the 7nm range in comparison
flag only1mikey
O+
Posted: May 18, 2016 at 15:01 Quote
jewpowered wrote:
From experience, fox ti springs fit in the 380 just fine, and the fox blue spring is noticeably stiffer than both the 5.5 and 6.5nm springs, I would put it up there in the 7nm ranger in comparison

Yeah makes no sense to me! Maybe I am doing the conversions wrong.

Anywho got the fork dialed in last night thanks to henkster's setting. Had to dial up the high and low speed compression a few clicks more than what he wrote down, but all is good now. I think a good portion of the problems I was having was having the Vivid Coil so far out of wack. I dialed in a lot more compression and rebound and the bike is feeling a lot more balanced now.
flag way2manyhobbies2keep
Posted: May 18, 2016 at 15:09 Quote
only1mikey wrote:
jewpowered wrote:
From experience, fox ti springs fit in the 380 just fine, and the fox blue spring is noticeably stiffer than both the 5.5 and 6.5nm springs, I would put it up there in the 7nm ranger in comparison

Yeah makes no sense to me! Maybe I am doing the conversions wrong.

Anywho got the fork dialed in last night thanks to henkster's setting. Had to dial up the high and low speed compression a few clicks more than what he wrote down, but all is good now. I think a good portion of the problems I was having was having the Vivid Coil so far out of wack. I dialed in a lot more compression and rebound and the bike is feeling a lot more balanced now.

your conversions are right nearest I can tell
flag henkster
Posted: May 18, 2016 at 17:53 Quote
jewpowered wrote:
only1mikey wrote:
jewpowered wrote:
From experience, fox ti springs fit in the 380 just fine, and the fox blue spring is noticeably stiffer than both the 5.5 and 6.5nm springs, I would put it up there in the 7nm ranger in comparison

Yeah makes no sense to me! Maybe I am doing the conversions wrong.

Anywho got the fork dialed in last night thanks to henkster's setting. Had to dial up the high and low speed compression a few clicks more than what he wrote down, but all is good now. I think a good portion of the problems I was having was having the Vivid Coil so far out of wack. I dialed in a lot more compression and rebound and the bike is feeling a lot more balanced now.

your conversions are right nearest I can tell

Sounds about right. I prefer a slightly more active bike than I think a lot of riders will. Adding a couple more clicks to each damping circuit will make the bike more stable and confidence inspiring over my setup.

I think I've settled on a set of settings that work better at higher speeds (for Cat 1 racing). My bike definitely feels a bit "off" for the first 30 seconds on the first run of the day, and then once I settle into things and the speed picks up then it starts to come alive. Flat out it's glorious, but at half speed the fork is a little quick.
flag AndRiEL
Posted: May 21, 2016 at 7:56 Quote
Hey guys!
What is the oil amounts for a CR forks? Manual is saying 80/80ml left/right leg. Is these 80ml dumper side means that 80ml is a total amount of oil in a right side of the fork OR extra oil needs to be in DBC also (68mm to the top like monkey said for c2r2 model).

- Lowers spring side: 80 ml - Lowers dbc side: 80 ml + 60-70 in the damper itself
flag way2manyhobbies2keep
Posted: May 23, 2016 at 14:20 Quote
AndRiEL wrote:
Hey guys!
What is the oil amounts for a CR forks? Manual is saying 80/80ml left/right leg. Is these 80ml dumper side means that 80ml is a total amount of oil in a right side of the fork OR extra oil needs to be in DBC also (68mm to the top like monkey said for c2r2 model).

- Lowers spring side: 80 ml - Lowers dbc side: 80 ml + 60-70 in the damper itself

80CC/ML IN THE LEG WITH THE DAMPER ALREADY PRIMED

WHICH TOTAL WAS SOMEWHERE AROUND 200CC
flag unuser1
Posted: Jul 2, 2016 at 0:59 Quote
Hi, I am servicing my 380c2r2 forks, as per some helpful information on this thread, as the rebound damping seemed to not be working properly. Also putting a ti spring in. I have the damper out of the fork, yet its not obvious to me where the oil cycles back in to the damper... the top holes where excess oil is dumped are perfectly obvious... can someone possibly reveal to me where/how the damper sucks oil back in please as there seems to be no obvious hole near the base!?
thanks!
flag Korli
Posted: Jul 4, 2016 at 3:40 Quote
unuser1 wrote:
can someone possibly reveal to me where/how the damper sucks oil back in please as there seems to be no obvious hole near the base!?
thanks!

at the base of the cartridge where the rod enters the main body there is a one-way seal.
flag mcozzy
Posted: Jul 21, 2016 at 12:43 Quote
Ok my turn to try to add some content that will hopefully be helpful to others.
After a week in morzine my 2014 380's felt terrible, squeaky, clunky on topout and very harsh. A hire bike I rode with some basic boxxers showed how bad mine were as they felt so much smoother over the braking bumps.

Its pretty much covered in this thread so I will skim over & fill in the gaps hopefully.
I removed the top spring bolt (33mm) and took the spring out (7.7nm titanium, thanks YT Big Grin ). The plastic spring cover was pretty shabby but I didnt replace it.
I removed the rebound knobs (small allen key)
I undid the 2 foot nuts (14mm spanner)
And caught the oil ..
photo
mmmmmm 1/4 a cup of crappy looking oil. Most of this was from when I added 100ml in the spring side when I was checking the spring weigh a few months back.

I then removed the top damper nut (33mm) and pulled the damper out.
The lowers can now be slid off
A circlip needs removing on the spring side to get the elastomer rod out, easily done with a small thin screwdriver.
All the bits laid out, lowers, elastomer rod, foot nuts, rebound knobs, circlip, spring, preload adjuster & damper.
photo

I cycled the damper & oil squirted everywhere from the top bleed hole.

Some general pics.

Space left on stanchions with forks at full compression.
photo

Length of standard elastomer. 170mm
photo

Travel left before elastomer hits the bumpstop with spring removed. I had previous though YT had cut my elastomer as full travel could be obtained. I now realise without the spring fitted, the elastomer is free to flex around in the stanchions and can be easily distorted.
photo

45mm cut off the elastomer with the bread knife. I was aiming for 40mm but am a terrible cut!
photo

Reassembly is straightforward reverse of the removal.
Plenty of slik suspension grease on the seals.
Remember to check the o-rings fitted to the damper bottom & the spring bottom. I hadnt realised one was stuck in the forks still.
photo

Now the damper bleed confuses me. I see it can be done using a really thin flat 24 or 26mm spanner I read about earlier in the thread to take the top off the damper. I did not have one of these. I had hoped that it would self bleed by reassemble, 110ml of oil in the damper leg then cycling the fork without the spring fitted. This appears not to work. I cannot see the lower bleed hole anywhere thats meant to suck oil up, its mentioned that its at the bottom of the black damper where the rod exits. I really cannot see how this would ever work as I dont think this part is ever submerged in oil. Anyone care to explain??

So I had to take the damper apart without the correct spanner.
Removed the LSC knob with small allen key.
I wedged a bolt against the HCS knob to undo the 8mm nut.
photo

Then remove the HSC knob. Dont loose the springs & ball bearings from either compression knob!
Now the damper can be undone with a 26mm socket. Ok I didn't have one, but a 27mm did ok, its not that tight.
photo

I then poured oil into the top of the damper. Hand over the top (or it will spray everywhere) & gently cycled it up & down, added a bit more and repeated until it felt like it was doing something. The top cap can then be screwed back in. This was a tight fit with the oil in there now.

And tighten everything back up.

Dont forget a travel o-ring whilst its in bits, rude not to.
photo

Out of my 500ml of 7.5 fluid I used about 350mm.
150ml in the spring side.
110ml in the damper leg, the rest in the damper.

Fork feel splendid just bouncing it, super smooth & silent & the damping adjustments now actually seem to work. I think it was so low on oil from the factory.
Looking forward to testing it Big Grin

EDIT: the only bit I'm not happy about is not taking the damper top off earlier & emptying the old oil out. I'm sure some of the crappy oil is still left after cycling it.
flag Kitejumping
O+
Posted: Jul 22, 2016 at 14:02 Quote
Question for anyone that just rebuilt their fork:

Can anyone take a hand scale and measure the breakaway force of their fork after a rebuild? (flip your bike, pull the wheel off, take a hand scale and zip tie, and pull down on the TA and measure how many pounds it takes to get the fork started moving in it's travel?)

Just got a new 380 c2r2 ti and the lightweight aspect of it is awesome, but it is the harshest DH fork I have ever owned. I thought Marzocchi was supposed to be buttery smooth? Spring preload and hsc/lsc all the way off.

Mine is somewhere way over 40lbs of force to get moving which is what my cheap hand scale maxes out at (brand new fork, has maybe 4 dh laps on it). For comparison, the new dhx2 on the rear of the bike takes less than 10lbs to get moving, and my older x-fusion rv1 downhill fork only takes 7lbs of force to get moving. This new fork causes way more arm pump than doing laps on my RV1. I suspect this is due to the fork sitting in a warehouse for a year and being completely dry.
flag henkster
Posted: Jul 22, 2016 at 14:08 Quote
Kitejumping wrote:
Question for anyone that just rebuilt their fork:

Can anyone take a hand scale and measure the breakaway force of their fork after a rebuild? (flip your bike, pull the wheel off, take a hand scale and zip tie, and pull down on the TA and measure how many pounds it takes to get the fork started moving in it's travel?)

Just got a new 380 c2r2 ti and the lightweight aspect of it is awesome, but it is the harshest DH fork I have ever owned. I thought Marzocchi was supposed to be buttery smooth? Spring preload and hsc/lsc all the way off.

Mine is somewhere way over 40lbs of force to get moving which is what my cheap hand scale maxes out at (brand new fork, has maybe 4 dh laps on it). For comparison, the new dhx2 on the rear of the bike takes less than 10lbs to get moving, and my older x-fusion rv1 downhill fork only takes 7lbs of force to get moving. This new fork causes way more arm pump than doing laps on my RV1. I suspect this is due to the fork sitting in a warehouse for a year and being completely dry.

Sounds like it's one of the dry ones from the factory. Pop it apart, empty fluids and replace with the correct level, and grease the seals. Mine takes maybe 2 lbs to move. It's the most responsive fork I've ever owned and is silky smooth all the way through the stroke, exactly how it should be.

I spoke to a few guys at Whistler/Northstar about problems with 380s and 90% of the time it's caused by dry seals and almost no fluid in the spring side from the factory, and/or too little fluid in the damper side that results in inconsistent damping.
flag Kitejumping
O+
Posted: Jul 22, 2016 at 15:21 Quote
henkster wrote:
Kitejumping wrote:
Question for anyone that just rebuilt their fork:

Can anyone take a hand scale and measure the breakaway force of their fork after a rebuild? (flip your bike, pull the wheel off, take a hand scale and zip tie, and pull down on the TA and measure how many pounds it takes to get the fork started moving in it's travel?)

Just got a new 380 c2r2 ti and the lightweight aspect of it is awesome, but it is the harshest DH fork I have ever owned. I thought Marzocchi was supposed to be buttery smooth? Spring preload and hsc/lsc all the way off.

Mine is somewhere way over 40lbs of force to get moving which is what my cheap hand scale maxes out at (brand new fork, has maybe 4 dh laps on it). For comparison, the new dhx2 on the rear of the bike takes less than 10lbs to get moving, and my older x-fusion rv1 downhill fork only takes 7lbs of force to get moving. This new fork causes way more arm pump than doing laps on my RV1. I suspect this is due to the fork sitting in a warehouse for a year and being completely dry.

Sounds like it's one of the dry ones from the factory. Pop it apart, empty fluids and replace with the correct level, and grease the seals. Mine takes maybe 2 lbs to move. It's the most responsive fork I've ever owned and is silky smooth all the way through the stroke, exactly how it should be.

I spoke to a few guys at Whistler/Northstar about problems with 380s and 90% of the time it's caused by dry seals and almost no fluid in the spring side from the factory, and/or too little fluid in the damper side that results in inconsistent damping.

Cool, you think 5wt torco rsf will work for all of it?

 


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