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Update: 66 RC3 Ti on Delirium T

5429 Views 47 Replies 18 Participants Last post by  OldschoolBMXer, 
KRob
4
I got a 2010 Marz 66 RC3 Ti 180mm Ti coil fork for Christmas and have 10 or 15 good rides in on it so far.

A few observations:

-Stack height stayed about the same as I was running quite a few spacers with my 55 RC3. I just removed a few of them. In fact I think for downhill and FR I'd prefer bringing the bar back up some. I'm running a Atlas FR lowrise bar now so maybe a bar with a bit more rise would be good.

-Climbing steep tech stuff doesn't seem to be affected much but on steeper smooth trails I do notice the front end wanders a bit more. Just takes a bit more concentration to keep it going straight. Not bad though.

-Action of the fork was pretty smooth right out of the box. I like the small bump sensitivity and it doesn't seem to bob too much on seated pedaling..... A bit boingy on standing sprints but not awful.

-I notice a faint looseness or soft rattle as it tops out when pedaling on smooth slightly inclined trails. Almost like a loose head set.... but it's not. It doesn't seem to affect anything. More something I hear rather than feel. Any thoughts? Marz famous QC maybe? If so, what's the source?

-Mid-stroke action in fast chop is solid, flex free, and tracks straight, but seems like it packs up a bit or is a little stiff through fast, rough chop although I'm running compression almost all the way out already. Compression knob is set at one click in from fully open. Speeding up the rebound may help with this but then it's too fast for slow tech and drops. Gotta find a happy medium because, more often than not, both these situations come up on the same descent. I'm running about 5 clicks out from fully closed for most stuff.
(Note: I edited this from the original)

-Drops and big g-outs get soaked up without complaint and without bottoming. In fact I'm not sure I'm getting full travel even on the bigger drops to flatish (although I haven't done anything too big with this fork yet). I haven't put on travel indicators yet so not sure but definitely haven't heard any loud clanky bottoming like I did on my 55. This is the main reason I switched to the 66 so score a win for the 66 there.

-On really steep descents I like the slacker head angle especially when there's chunky wheel-stoppers in the path. Although it does seem to dive a bit too deep into its travel in these situations thus negating some of the advantage.... but the 55 did this too so the 66 is still slacker.

-I'm a bit confused on the adjustments. There's an air valve on the top of the left fork leg that I assume is the air pre-load like on my 55 RC3, but the top of the red knob on the right fork leg has an arrow and the words Spring Stiffness. Are there two ways to adjust spring preload or is this something different?

Any insight or set-up tips from those who've used the 66RC3 are much appreciated.

A few pics from my recent trip to AZ for "field testing".:thumbsup:







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craigstr
A few words from the resident marzocchi hater.

That "looseness" you feel is the the bushing play. Marzocchi gets that buttery smooth initial stroke by having looser bushings then the other companies. If you take your front wheel off and take one fork leg in each hand and squeeze and pull them ever so slightly in and out you will feel the play. I've owned 3 66 forks and they all had that slight play out of the box. It only seems to be at the top of the stroke so if you run a little more sag (less air preload) the top out loosesness seems to lessen. I thought the knob on top of the right leg was rebound?
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dulyebr
Krob, did you ever figure out the DHX?
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Dude!
The knob on the right is spring preload. You may want to tinker with spring load versus the coil preload as they affect progressive behavior and your midstroke.

I wish the fork had a bit more independent controls instead of rebound for both hi and lo and compression for hi and lo.

I like the Marz when the trails get rough. However since riding the 2011 Fox Float, I really like the Fox fork and its damping behavior. When I throw the Marz 66 on, I wish it had characteristics of the Fox. I do not like the lack of midstroke on the Marz. There hasn't been much that I don't use the Fox for.

One thing I noticed since riding the Fox more, is that my wrists don't hurt anymore. I can't put my finger on it but the Marz must be harsher in some circumstances. It may be its progressiveness...I am not 100% sure.

These are based on the 2010 RC3, the 2011 has better midstroke support. I liked it more.

At one point, we found that oil level in the damper side affected the use of the forks travel. Remove a little and it helps!
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KRob
craigstr said:
That "looseness" you feel is the the bushing play. Marzocchi gets that buttery smooth initial stroke by having looser bushings then the other companies. If you take your front wheel off and take one fork leg in each hand and squeeze and pull them ever so slightly in and out you will feel the play. I've owned 3 66 forks and they all had that slight play out of the box. It only seems to be at the top of the stroke so if you run a little more sag (less air preload) the top out loosesness seems to lessen. I thought the knob on top of the right leg was rebound?
Click to expand...
If that's the price to pay for the buttery initial stroke I'm OK with that. I'm not sure I want to run more sag though... I think I'm already running about 2.25" though I'll double check it. I'm afraid if I run more the diviness on steep descents will get worse. What I want is a little stiffer spring to keep it up in it's stroke better and freer flowing compression damping.

The rebound is on the top of the left leg along with the schaeder air valve with the compression on the bottom of the left leg. The right leg just has the big red knob for spring stiffness which I have set fully soft.

So I'm still confused as to what the air assist on the damper side does.
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KRob
dulyebr said:
Krob, did you ever figure out the DHX?
Click to expand...
No not totally. It works pretty well but not great. I'm just kind of putting up with it until I can get the money together to send it off for the MX tune. Come to think of it... its action closely mimics the feel of this fork: A little constipated in midstroke on fast chop but doesn't bottom... So at least I'm pretty balanced front and rear (although the initial stroke isn't quite as plush as the Zoke's.)

If I set the rebound fast enough to handle the chop it behaves poorly off jump limps and in slow techy chunk. It really needs the separate hi/lo rebound damping (or a speed-sensitive rebound damping like the Elka).
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KRob
Dude! said:
The knob on the right is spring preload. You may want to tinker with spring load versus the coil preload as they affect progressive behavior and your midstroke.
Click to expand...
Are you talking about spring pre-load on the fork versus the coil preload of the shock? And if so....am I trying to match front and rear progressiveness by said tinkering? Or are you talking about something else altogether?

Dude! said:
At one point, we found that oil level in the damper side affected the use of the forks travel. Remove a little and it helps!
Click to expand...
Thanks, I'll try that. How much should I remove and what's the best way to do that?

Did you get the new Avalanche cartridge for your's yet .... or was that someone else?
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woodyak
This fork is a strange one to tune. Everything you say about this fork I have experienced as well. To fix the bottom out issue I had to remove some oil from the left leg. This of course make the fork a bit more linear which sucked. To combat that I tried everything and the only thing that seemed to help me was adding more coil preload. It helped but it wasn't great. I found the compression preload (one on the bottom of the leg) just made everything less plush so I left that off. The air preload seemed to make things more progressive, which never was a problem for me. I found that just a couple of pumps made a difference. 8 pumps made the fork way too stiff. I ended up running it with no air pre-load because it made things to stiff and overly progressive. Keep in mind that I weigh 150 so I'm at the lower end of the medium spring.
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craigstr
Couple things to try

I was running 10w Maxima oil in mine which firmed up the midstroke, stock fluid is 7 w. You cant put more than a few psi in the air assist, I used to count the number of pump strokes asa guide. I run a DHX 5 on my DT, I think the 2 most important adjustments are the boost pressure and bottom out dial. I run 125-150 in the boost valve and only 5/8 of a turn from full open on the bottom out. Any more than that and the suspension will be very spikey which might be what you are feeling off jump lips and in the chop. Its definetly a constipated shock.
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11053
KRob said:
If that's the price to pay for the buttery initial stroke I'm OK with that. I'm not sure I want to run more sag though... I think I'm already running about 2.25" though I'll double check it. I'm afraid if I run more the diviness on steep descents will get worse. What I want is a little stiffer spring to keep it up in it's stroke better and freer flowing compression damping.

The rebound is on the top of the left leg along with the schaeder air valve with the compression on the bottom of the left leg. The right leg just has the big red knob for spring stiffness which I have set fully soft.

So I'm still confused as to what the air assist on the damper side does.
Click to expand...
The air assist will help address most of the issues you describe above.
You"ll be able to dial out brake dive as well as get more out of the compression adjustment by adding some air.
It won't need much air-but try using a low pressure(floor) pump with an accurate gauge.
A high pressure shock pump probably won't be accurate at the low PSI range for the air assist feature of this fork.

Air range for most riders should be 0-15psi. You will notice a HUGE difference how firm the fork feels over this small range, so you really need an accurate gauge. Leave the black rebound dial on the fork and just insert the "needle" after removin g the air cap. By removing the rebound dial and air cap, you will let the air out of the chamber when you thread the needle on the valve.

Best to mess with all the stock adjustments before tweaking oil volumes and weights.

The stock spring covers a wide range of riders. I used to run heavy springs in my Totem, but I can run the stock Marzocchi Ti spring with 12psi air assist and all is good.
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Dude!
Marz fork

KRob said:
Are you talking about spring pre-load on the fork versus the coil preload of the shock? And if so....am I trying to match front and rear progressiveness by said tinkering? Or are you talking about something else altogether?

Thanks, I'll try that. How much should I remove and what's the best way to do that?

Did you get the new Avalanche cartridge for your's yet .... or was that someone else?
Click to expand...
Folks already said much of this- the fork supports air and coil preload. The coil right leg is a soft spring, I never noticed much in the sense of turns with it, so most of the preload comes from air. I am a bit heavier 180-185lbs and used 6-8 pumps, more than 8 pumps it got too progressive. Compression (lower leg) just a few clicks, as this seems more to be an on off knob then a dial. Rebound seemed okay.

Yes, I got the Avalanche and when I installed it, I had way too much sag. Since the cartridge replaces the air preload and Craig at Avalanche doesn't like air, I needed to bump up the spring weight on the right leg. I am in the middle of this now - just waiting for parts. It will probably be another week until it is back together. I am hoping that it feels like a bigger Fox Van with better midstroke:)!!

Oil level makes a significant differences - trial and error is the best method.
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KRob
Norman Clydesdale said:
The air assist will help address most of the issues you describe above.
You"ll be able to dial out brake dive as well as get more out of the compression adjustment by adding some air.
It won't need much air-but try using a low pressure(floor) pump with an accurate gauge.
A high pressure shock pump probably won't be accurate at the low PSI range for the air assist feature of this fork.

Air range for most riders should be 0-15psi. You will notice a HUGE difference how firm the fork feels over this small range, so you really need an accurate gauge. Leave the black rebound dial on the fork and just insert the "needle" after removin g the air cap. By removing the rebound dial and air cap, you will let the air out of the chamber when you thread the needle on the valve.

Best to mess with all the stock adjustments before tweaking oil volumes and weights.

The stock spring covers a wide range of riders. I used to run heavy springs in my Totem, but I can run the stock Marzocchi Ti spring with 12psi air assist and all is good.
Click to expand...
Thanks for the suggestions Norman. I assume from your username that you are a bigger guy. I wonder if the same suggestions apply to me at 160lbs. It seems like there's already too much high speed compression damping in the mid-stroke even with the compression knob turned almost all the way out (one click from fully open).

Will increasing the air assist by 12psi (assuming I'm at zero now) as you suggest really increase the range of compression settings towards less dampening? Seems counterintuitive, but I know some things are like that. More low speed dampening may help with some of the diviness on steep descents and bob on standing sprints, but I'm afraid it may make the high speed dampening more constipated as well.
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KRob
woodyak said:
This fork is a strange one to tune. Everything you say about this fork I have experienced as well. To fix the bottom out issue I had to remove some oil from the left leg. This of course make the fork a bit more linear which sucked. To combat that I tried everything and the only thing that seemed to help me was adding more coil preload. It helped but it wasn't great. I found the compression preload (one on the bottom of the leg) just made everything less plush so I left that off. The air preload seemed to make things more progressive, which never was a problem for me. I found that just a couple of pumps made a difference. 8 pumps made the fork way too stiff. I ended up running it with no air pre-load because it made things to stiff and overly progressive. Keep in mind that I weigh 150 so I'm at the lower end of the medium spring.
Click to expand...
This makes sense. I'm hesitant to add air preload because it's almost too progressive as it is. I wouldn't mind it being a bit more linear as long as I still had some ramp up at the end to prevent harsh bottoming.

Maybe less (or lighter weight?) oil would improve the mid-stroke flow then I could prop it back up with the air assist to keep it up in its stroke and add back in some progressiveness at the end of the stroke.
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S
To me, the air preload is exactly like changing oil height, except that you don't have to change the oil. Changes how progressive the overall spring rate is. I think if you put 12psi in there that you'll wish you had put a cromoly steel fork on there instead!!

I had a hard time getting enough sag on mine. Maybe because my legs are too long and all of my weight is over the rear, I don't know. Anyway, I took some oil out of the spring side, and left the rc3 side at 70mm. Still not enough. So I put the little valve thingy into the schraeder valve and pushed the fork down a couple of inches, then unscrewed the valve thingy. WahLah negative air preload! Got the sag where I wanted and the small bump performance was much improved!!
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11053
12psi is my setting. It's not the setting that I would recommend for you. Manual gives 0-15 as the range of air pressure.

Try 1-2 psi at a time and see what you think. Just a bit of air pressure makes a big difference.You will notice the difference with even 1psi in there.
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KRob
scooter808484 said:
To me, the air preload is exactly like changing oil height, except that you don't have to change the oil. Changes how progressive the overall spring rate is.
Click to expand...
Hmm. Now that you mention that... I think I've read that somewhere else.

scooter808484 said:
So I put the little valve thingy into the schraeder valve and pushed the fork down a couple of inches, then unscrewed the valve thingy. WahLah negative air preload! Got the sag where I wanted and the small bump performance was much improved!!
Click to expand...
Cool. So besides allowing you to get proper sag.... does it also decrease the progressiveness of the overall spring rate?

So is it a matter of just letting out some pressure when the fork is compressed or do I have to use some special "valve thingy"... Or are you just talking about the valve core of the schraeder valve? A little confused on your description.

Oh, and how much do yo weigh?
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S
The little valve thingy is the valve extension that screws into the schreader valve that came with my fork. You could also compress the fork an then poke the valve to let air out of the fork leg, but you might need someone to help hold the fork down.

It does make the spring more linear as there is less air spring effect. Since I wasn't using anywhere close to all of the travel, that was actually a good thing. You could make the change permanent by taking some more oil out, but with the air trick all you need to do if you start bottoming is take the rebound cap off and let air into the leg.

Of course, as with everything suspension related, this made the thing bob more on pedaling, especially standing. My routine was 10-12 clicks of LSC on the fire road climb up, 3 clicks LSC for the bomb back down, and if I was on a rolly pedal trail somewhere in between. The rest of my settings: 5-6 clicks of rebound, no coil preload, 1.5-2 inches of negative air. Stock weight oil though it has been changed.

I weigh about 190, so close to you. Like I said, I'm not sure why I couldn't get the fork to sag but I've got pretty long legs so I guess all of my weight hangs out back.

By the way, if you start messing with oil viscosity, do yourself a favor and don't rely on the 7.5 weight designation. That can mean darn near anything.

http://www.peterverdonedesigns.com/lowspeed.htm

Check out the information there. Really good info on suspension and oil in particular. I cross checked the viscosity with other charts and they read the same. My next change will be to Silkolene to get a low VI so the weather won't change my fork.
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titusbro
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No 'Dis intended, but...

...I am freakin' lovin my FOX 36 Talas 180! Buttr' on wheels!

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Jayem
Not suprised it can feel a bit harsh, it's probably the lack of mid-stroke support+inferior ported rebound orofice. I have an older 66 up front, and it can definitely get this way, while my rear avalanche shock with high/low compression is absolutely stunning. The thing is that the RC3 Evo cartridge isn't really all that much better (I have an RC3 888 as well), sure it's got the adjustable shim-stack, but same fairly lame rebound control and pretty crude low and high speed compression, abiet better than years before. I wouldn't buy a new marzocchi just due to how much more advanced fox and RS stuff is. Sure, you might be checking the lubrication oil levels/servicing more, but it will be worth it IMO. The only other option is to buy a $300+ avalanche cartridge for your marzocchi, thereby giving you the control and damping that you really deserve at this point (from a technology point of view). Marzocchi has been taking the path of least resistance for years with their dampers, they did a huge upgrade with RC3 Evo, but that's everyone else had far surpassed them, and RC3 Evo is still pretty crude compared to what RS and Fox use. I think most people just want RS and Fox to use a better open-bath system that doesnt require the frequent break-downs and such, but they are not that bad in this respect and it's worth it.
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KRob
titusbro said:
...I am freakin' lovin my FOX 36 Talas 180! Buttr' on wheels!
Click to expand...
The Fox 180 was definitely on my list and I've heard good things about them but it was hard to ignore that $488 on the 66. Sounds like you're enjoying yours.

PS: nice looking chunk. Are you going to do Goat camp with the guys this Saturday? Wish I was there.
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