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  1. #1
    Lord Thunderbottom
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    Big guys fork adjustment

    I have an 05 marzocchi EXR 100mm and I'm haivng a little trouble getting it right where I want it

    I'm right around 270#s the spec sheet doesn't go this high for air pressure, 210-220# riders should be at 55-65psi so I set it to about 80 and then preloaded the spring to the proper 20% sag, it's still a little too bouncy on the flats when standing up and pedaling and it compresses too fast when forced into mud etc (yes I know I need to pull up a bit more and lean back a bit more as well)

    also there is no max air pressure listed anywhere in the manual but I'm afraid to run it too high

    any suggestions? time for a different fork?

    Thanks!

  2. #2
    mtbr member
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    Good thread topic. Unfortunately I can't help you, but am in the same situation with my Reba.

    Does anyone know of an existing resource for settings over the factory charts? Or maybe we can collect what MTBR members are doing and make this a sticky.

  3. #3
    Lord Thunderbottom
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    100 views and no one here that weighs over 220#s has adjusted a fork?

  4. #4
    Former Bike Wrench
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    If you have one of the EXR models with an oil damper, increasing the oil weight and/or height over the stock oil will help control the fork better and offset the high psi.

  5. #5
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    I'm going through the same issues with an 04 Manitou South fork. I found out they they made three different spring kits for it. I called my local bike shop, and they located the stiff spring kit, and it costs about $35 for the parts. Supposedly it's an easy fix, and will stiffen up the fork considerably.

  6. #6
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    I've read that about the Manitou forks, and it sounds like it makes a big improvement for bigger guys. Not sure how the air pressures change on their air forks though.

  7. #7
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    I don't know that model of Manitou, but it could be a coil spring only fork. The OP's Zoch sounds like it has a hybrid air/coil set up. In '05 the EXR came in 4 models that including coil-only, air-only, and coil/air. The OP probably would see a benefit from getting a stiffer coil spring if the fork is partly/wholey coil sprung.

    I ran an EXR Pro for a while (air-only) with pressure extrapolated past the highest value in the owners manual to a level appropriate for my weight. I had no problems, but it did have a bit of pogo stick feel.

    I got some directions on how to service it off the suspension forum here at mtbr--let me know if you can't find them and I will post. I was about to start trying some of the the things mtnbiker72 suggested, but then I got a reba.

  8. #8
    Lord Thunderbottom
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    so let me see if I have this correct after some more reading, my fork is the regular EXR, coil and air

    the spring in the left side is what causes the fork to rebound and also has the most impact on the sag, which is why my "fatness" requires me to have the preload set at max

    the air in the right side is the damper that keeps the spring from bottoming out fast/hard

    so if I can swap to a stiffer spring I can adjust the sag a bit more (or at least not have it maxxed out) and it won't compress as fast when running a lower PSI on the other side?

    also adding oil to the air side will also allow me to run a lower PSI there as well?

    Thanks for all the help guys

  9. #9
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    Yeah, as far as Manitou goes, they offer three different springs up to clydsdale. Call the manufacturer or an authorized dealer and find out if they offer something similar to your setup.

  10. #10
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    I'm no suspension expert, we need to get someone like mtnbkr72 to respond to your questions, but here goes.

    A stiffer spring should allow you to run less pre-load. "Pre-load is the distance a spring is compressed, from its free length, to its installed length." "CHANGING PRE-LOAD DOES NOT CHANGE SPRING RATE. You donít get a stiffer spring by adding pre-load." (from link below). Getting a stiffer/firmer spring should slow the speed at which the fork compresses, and that may alleviate some of the pogo-like feel.

    I doubt the air on the right side is a damper, dampers usually involve oil. According to the manual the right side has a 'positive spring' adjustment, so it helps the coil spring prevent the fork from compressing.

    I'm pretty sure you are correct that a stiffer spring would allow you to run less pressure on the air side, this might also help achieve a softer ride since the spring rate for air springs tend to ramp up near the end of their compression cycle.

    I don't think adding oil to the right side would allow you to run lower psi. I think it would increase the damping--damping slows the movement of the suspension.

    Threaded Spring Preload

  11. #11
    Bnerd
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    I had a similar issue with a different fork but it still is a Marzocchi fork.
    I'm 6'6" and 245ish lbs.

    I have a 2008 Marz 55 TST Micro. I took it in to Marz to get the issue sorted out.
    What I was told by the person who serviced the fork was that the coil stays the same (no swapping to a stiffer coil) but he had changed the oil weight on the compression side. And, to adjust the stiffness overall I was to play with the air setting (the air pressure is like a virtual oil level).

    The fork works great now and I have a great range of adjustability for the different types of terrain and riding I do.

    I know it isn't the same fork but most Marz forks are similar enough across the lines that the adjustments and tunings are similar.

  12. #12
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    it was suggested by my lbs to put thicker oil in my marz bomber 0.3 exr,i am 280/290lbs.

    it work realy good what a difference,could jump ,take last second drops and dips,run over roots etc...

  13. #13
    Former Bike Wrench
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    Many of the base Marzocchi forks had air pre-load in the right leg, and still has the very primitive and non-adjustable SSV damper. It's often referred to as a pumping rod, just a ported piston...about as simple as it comes for oil damping.

    Stock 2005 EXR 105 with oil damping used 150cc's of Marzocchi 7.5wt oil (Spectro Golden Very Light). Increasing oil weight with something such as a 10wt from Maxima, Spectro, or Bel-Ray will help for a bigger rider. Sometimes increasing the oil height a little (but not too much as it can cause the fork to lose travel) will help as well. I would go 5cc at a time until the feel works for you.

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