Results 1 to 18 of 18
  1. #1
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245

    lower rating titanium spring needed for 170 mm Marzocchi fork

    (edited - see below for updates)
    Last edited by rshalit; 07-22-2013 at 01:28 PM.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    (further edit: continued updates below)

    Anyone know anything about changing the shim stacks - how it might alter performance, how to do this?
    Last edited by rshalit; 07-22-2013 at 01:30 PM.

  3. #3
    otb club member
    Reputation: Chris2fur's Avatar
    Join Date
    Jan 2004
    Posts
    2,198
    Quote Originally Posted by rshalit View Post
    cancel my thread above - apparently there is no other titanium spring available for the 170 mm fork, according to Marzocchi.

    Anyone know anything about changing the shim stacks - how it might alter performance, how to do this?
    I think you are right about the 2013 spring being stiffer at the 6.9 N/mm rating than the previous stock springs for 55 coil forks. Also right about the new ones for 170mm forks only coming in the one "stock" rating. I'm guessing there is only so much you can do on the damping side to overcome a spring that is too stiff for your weight. I got slightly better results switching to 2.5 wt. oil. I'm only guessing here, but maybe Marz decided with their limited 2013 production to "average" the spring rate and only make one spring for the 55 RC3 V2. Whatever the reason, I'm not happy they don't have spring options. If they were going to only concentrate on a few models then they should have done a thorough job on those limited fork offerings. I doubt you and I are the only ones Marz is hearing from. Hopefully a lighter spring will be forthcoming.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    Thanks for letting me know I'm not the only one out there with this issue concerning the 2013 Marzocchi 55 RC3 EVO v.2 Ti (170 x 35) mm open-bath/coil fork.

    How much difference did the 2.5w oil make - anything quantitative in travel gain? (Do you think the viscosity of 2.5w is high enough to remain in the bushing grooves?) I was thinking of 5w. Did you find instructions anywhere on how to change the RC3 leg oil? Just turn it upside down and replace with new? What is your height of oil above RC3 "cartridge"? I think the minimum must be that the cartridge is completely covered when the rod is pulled all the way up, ie, the fork is compressed fully with spring out.

    Are there any instructions/information on how to change shim stacks and what that might achieve? I'm surprised by the lack of information and literature available for this fork. It is very plush, and the rebound is much sweeter, compared to my Float 160 RLC, but hopefully Marzocchi will come out with a lower spring rating.

    I assume you forced at least some air out of the headspace above the RC3 oil bath to create a negative pressure relative to atmospheric - do you find it stays out, that it is truly sealed?

    Some other notes:

    -the fork bottoms out (spring removed) with 6 mm of stanchion still showing.

    -rebound 15 clicks out from full clockwise (from full damping)

    -my weight 155 - 165 lb with water & gear

    -when stanchions are fully extended, pulled out as far as they will come from the legs, the total length of stanchion is 168 mm.

    -this makes for an actual maximum travel potentially achievable of 162 mm (although I don't know if, when the spring is in the fork, that the spring somehow decreases the travel when it's fully compressed).

    -taking that into account, the maximum travel I have yet to achieved (zero pre-load on spring, compression knob all the way to negative or soft, ie, no high speed damping), is about 159 mm - and that's trying to land front-heavy on drops, shoving my weight into the fork on fast rolls into a dip that shoots up out the other side, trying to compress the coil, etc.

    -I wonder if the titanium coil weakens with time - ie, the force required to compress it per mm will lessen, ie, drop from current new rating of 6.9 N/mm?
    Last edited by rshalit; 07-22-2013 at 01:30 PM.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    redux: after speaking with Marzocchi-Canada today, I am told that the solution to my situation is to get a new shim stack, which is done & ordered for each rider's specific parameters in consultation with Marzocchi-Italy engineers.

    Once the snow is too deep to ride Mojo HD, I'll pull Pugsley out of the basement and send this fork into Marzocchi for a shim stack replacement.

    I am liking this fork more and more each ride - sweet linear compression with fast, smooth rebound! Nothing harsh like with air-sprung cartridge-damped forks.

  6. #6
    otb club member
    Reputation: Chris2fur's Avatar
    Join Date
    Jan 2004
    Posts
    2,198
    Quote Originally Posted by rshalit View Post
    redux: after speaking with Marzocchi-Canada today, I am told that the solution to my situation is to get a new shim stack, which is done & ordered for each rider's specific parameters in consultation with Marzocchi-Italy engineers.

    Once the snow is too deep to ride Mojo HD, I'll pull Pugsley out of the basement and send this fork into Marzocchi for a shim stack replacement.

    I am liking this fork more and more each ride - sweet linear compression with fast, smooth rebound! Nothing harsh like with air-sprung cartridge-damped forks.
    Hey, Rshalit: Wish you hadn't edited all your previous comments and questions away. I know you had updated info, but, IMO, it's useful to see the progression in the thread. Anyway, I wanted to get a more objective measurement than I was able to provide before by going to a trail that I ride regularly and know the travel range I was getting. After getting vacations and such out of the way I was finally able to do that and was pleasantly surprised to find that, with the 2.5wt oil I was able to get an additional inch of travel in comparison to the stock oil. That is a very conservative estimate, btw. Based on that, I am much more optimistic than I previously was about a shim stack change making much difference.

  7. #7
    mtbr member
    Reputation: rscecil007's Avatar
    Join Date
    Apr 2007
    Posts
    2,147
    Quote Originally Posted by Chris2fur View Post
    I think you are right about the 2013 spring being stiffer at the 6.9 N/mm rating than the previous stock springs for 55 coil forks.
    Does anyone know off hand what the 2012 stock ti spring rating was? I just had mine out a few weeks ago to re-shrink wrap it, but I can't remember. For some reason 5.5 N/m rings a bell, but that seems really soft. But again, could be correct since I'm running 20 or 30 clicks of preload on it, and I'm about 215 lbs read to ride.

    If mine is 5.5, then the 6.9 would probably feel really good...
    If jackasses could fly this place would be an airport.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    sorry about that - let me know if you have questions.

    The bottom line for me is that this fork outperforms all of my Fox air forks for my weight and riding styles. I am confident that Marzocchi will come up with a solution for lighter users.

    The last time I spoke with Marz Canada I was told shim stack change would help. A couple days later I spoke with Marz USA and was told that unless I was getting proper sag, which I am not, changing shim stack won't help. Unbelievable to get continuously conflicting information.

    edit: Now the latest: Marzocchi Italy sez shim stack change-up should help(!)

    I also called Renton Coil Spring to find out about titanium spring fatigue, as they custom CNC Ti springs for snowmachines and other vehicles, but not mountain bikes. The engineer there told me titanium alloy coil springs fatigue much more slowly over time than does steel. So then I was talking again with Marz USA and the guy there told me the exact opposite! (help!)

    I'm glad and surprised to hear that 2.5w made that much difference in travel - you're saying at least 25.4 mm more travel. Again, Marz told me that lighter oil would only change the rate at which the oil moves through damper ports and shim stack, and would not change travel.

    So far I have possibly reached full travel one time, and that was slamming down into a ditch and shooting up the other side, but I didn't actually measure (remember that when fully compressed, spring removed, there are still 6 mm of stanchion showing) -that was with significant negative pressure above damper oil bath, and then the stanchions never fully extend -I mean without rider on bike, standing next to bike, pushing down hard and as fast as possible lifting front end all the way up so tire comes off ground - I have since let a little air back in as I'd rather the stanchions extend farther, so they now only stay in maybe 3 or 4 mm. That gives me a maximum potential of 160 mm of travel.

    Downieville today, Mr. Toad's tomorrow - 13,000 feet of climbing in past 5 daze - no recovery, quite toasted...
    Last edited by rshalit; 08-02-2013 at 12:00 PM.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    from what I can gather, the 2012 & 2013 on the 55 RC3 EVO v.2 Ti 170 are both 6.9 N/mm.... have you tried increasing air pressure above the bath? That's supposed to help with heavier riders, along with increasing oil volume in both legs.

  10. #10
    otb club member
    Reputation: Chris2fur's Avatar
    Join Date
    Jan 2004
    Posts
    2,198
    Quote Originally Posted by rshalit View Post
    from what I can gather, the 2012 & 2013 on the 55 RC3 EVO v.2 Ti 170 are both 6.9 N/mm.... have you tried increasing air pressure above the bath? That's supposed to help with heavier riders, along with increasing oil volume in both legs.
    I hope that's not true. I've been looking to trade springs with a 2012 rider (he wants stiffer, I want lighter spring). He should have it pulled out in the next day or so and we'll see what it says...

  11. #11
    mtbr member
    Reputation: rscecil007's Avatar
    Join Date
    Apr 2007
    Posts
    2,147
    I swear mine is 5.5 N/m but I will pull it out and verify it this weekend and report back. Mine is a 2012 model (last year they said "Marzocchi" down the side instead of the really big "55" graphic).

    I did call Marz earlier this week and they told me they all came stock with the 5.5 spring,...so I'm not sure what to make of that.
    If jackasses could fly this place would be an airport.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    could be - I'd like to know for sure - but just so you don't get your hopes up too high: Marz has repeatedly told me, and I'm talking about Marzocchi USA, Canada, & Italy, and that's 6 different peeps altogether from Marz, and additionally, I contacted both US and European suppliers looking for a different spring because Marz USA originally told me that there was indeed a lower rated spring available before telling me, a week later after I searched and searched, that they had erred and that there is no other 170 mm titanium spring other than 6.9 N/mm. I believe the 5.5 N/mm is only for the 160 mm fork (pre-2012), for which there are indeed, apparently, 4 different titanium springs available.

  13. #13
    mtbr member
    Reputation: rscecil007's Avatar
    Join Date
    Apr 2007
    Posts
    2,147
    I'm headed home and I will pull it out and verify soon as I get there.

    I did get mine from a now pro (I think) back in the winter who was sponsored by them, so I guess it's possible he got some team only spring. But mine bolts up fine, has 170+mm of stanchion showing, so I think I can safely assume it doesn't have a 160mm spring in there.
    If jackasses could fly this place would be an airport.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    245
    yours definitely not a 160 mm in that case - so if someone has a different spring other than 6.9, it means someone has a CNC machine coded & can make more (!)

  15. #15
    mtbr member
    Reputation: rscecil007's Avatar
    Join Date
    Apr 2007
    Posts
    2,147
    Unfortunately I have no good news to report. I was totally wrong, and my fork does indeed have the 6.9 N/m spring.

    I do have a 5.5 N/m Ti Marz spring, but it was out of my 888 Evo Ti and is sitting on my workbench, which is must be why I thought my 55 spring was the lighter weight one. I apologize to anyone for my confusion, who's hopes I may have gotten up.
    If jackasses could fly this place would be an airport.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    1,359
    slightly off topic here, but i'm looking to trade a 7.3 for a 160mm 2010 55 ti 6.5 or 5.5. anybody interested?
    breezy shade

  17. #17
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    1
    Having the same problems with my 55 rc3 evo v2. I´m quite small and light (50kg), so doesn´t get fulltravel. The fork is really amzing feels so plush inspite of the fact that i Max get 150mm travel don´t have enough sag. Did you guys ever find a solution to the problem?

  18. #18
    otb club member
    Reputation: Chris2fur's Avatar
    Join Date
    Jan 2004
    Posts
    2,198
    Quote Originally Posted by NóiNPO View Post
    Having the same problems with my 55 rc3 evo v2. I´m quite small and light (50kg), so doesn´t get fulltravel. The fork is really amzing feels so plush inspite of the fact that i Max get 150mm travel don´t have enough sag. Did you guys ever find a solution to the problem?
    No luck. Only one spring for 170mm 55. I was at one time looking into getting a 160mm spring and making my own spacer or adapter, but Marz USA told me it would not work and would not cooperate with me. Finally gave up and sold the fork to a heavier rider.

Similar Threads

  1. What CCDB spring rating do you run on your Demo?
    By FrankRizzo in forum Specialized
    Replies: 2
    Last Post: 04-01-2013, 02:13 AM
  2. Replies: 0
    Last Post: 10-02-2012, 09:11 PM
  3. 2012 Marzocchi - 66 RC3 Evo Titanium - 888 RC3 Evo Titanium V2
    By Nick_M2R in forum Downhill - Freeride
    Replies: 57
    Last Post: 07-05-2012, 08:00 PM
  4. Demo 8 spring rating? 200 lb rider
    By o3zone in forum Downhill - Freeride
    Replies: 5
    Last Post: 12-19-2011, 09:07 AM
  5. Demo 7 spring rating
    By darkzeon in forum Specialized
    Replies: 3
    Last Post: 06-13-2011, 10:28 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •