To Sag or not to Sag... What is Perfection??

Discussion in 'Trials' started by Beatprojim, Nov 29, 2018.

  1. Beatprojim

    Beatprojim Beatprojim

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    40 years of dirt biking and paying attention to suspension action and how the sag in the suspension can affect so many things, the trials community has me befuddled. On one hand RY suggests about an inch of “free sag” (free sag = bike settles a bit with no rider) . On other hand there are others that suggest zero sag. ADV members like Lineway says that it is not important but we just need to make sure the front and rear suspension works together.

    Let’s assume that you can get your suspension balanced perfectly front and back and you have dialed in the steering that you want. In a perfect world, would you have some sag in your perfect set-up?

    In my mind, a bit of sag allows the rear wheel to drop into holes a bit which may allow the tire to maintain traction. A tightly sprung rear may skip the holes and allow the wheel to spin. Likewise, when hitting an obstacle, a shock with a bit of sag will rebound fully without pushing the bike off the obstacle where the no-sag shock will continue to push until the shock is fully extended.

    As my cognition of trials suspension has been compared to that of a man that is “paralyzed from the waist down” (thanks heffergm) it is obvious that I need some help. Looking forward to your comments! (as long as I am not called retarded, ugly, and/or fat in addition to being paralyzed). Thanks
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  2. lineaway

    lineaway Long timer

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    So there I was two weeks before the first national of 2018 pondering the same thing. To set sag or no. My bike had been working flawlessly, but hoping to get the suspension a little tighter to make ip for my sloppy hoping ability.
    So after much fiddling, I settled on about 1 3/4 inches. By golly it felt great on my sections in the yard. Fast forward to section three first loop at the Roswell National. It had a tricky turn to three small humps up a steep loose hill. I rode it like a cowboy coming off his bull, I was everywhere except on the pegs. The damn Blonde scoring the section informed me how bad I suckes and my sons GF agreed with my wife.
    So I am using a rock on a screw driver at section 4 loosenng my rear shock humiliated at how dumb I was to set sag. But I felt better than the Vertigo rider whose bike would not start.
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  3. jonnyc21

    jonnyc21 Trials Ninja

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    My 2 cents... Yes the best setups will have some sag.

    From what I have found when I setup a bike with everything evenly working together and get it as close to 35% rider sag as I can get I like it the best. Also, they don't have the "On The Pegs" issue up any more, however they did a story reviewing sag on the trials bikes and the best results seemed like they had 38% rider sag with correct springs and setup front and rear.

    Well, hope that helps.
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  4. lineaway

    lineaway Long timer

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    P.S. My suspension still has not been touched since my trail adjustment in April.Ha!
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  5. jonnyc21

    jonnyc21 Trials Ninja

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  6. heffergm

    heffergm Long timer

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    For the rear: 10mm static sag, 80mm rider sag. Heaven.

    P.S. get the right spring for your weight
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  7. 2whlrcr

    2whlrcr gooligan

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    I'm having a hard time following this response...because I'm a little dull sometimes. So the OP is talking about free sag (no rider), are you saying you had 1.75" of free sag, or rider sag?

    All I know is I have about .25" of free sag on my TRS.
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  8. 2whlrcr

    2whlrcr gooligan

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    Damit, this is America here, quit talking Chinese.
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  9. heffergm

    heffergm Long timer

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    Sorry, 1/2" static and 3" rider in old money
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  10. alpineboard

    alpineboard Been here awhile

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    right on
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  11. wheelieman14

    wheelieman14 Adventurer

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    You do realize static &/or free sag numbers need to be set for Front AND Rear suspension. Stating "Free" Static Sag & total rider sag numbers only mean something if you indicate front or rear measurements...

    I do agree that correct springs for your weight is much more helpful, than just cranking preload adjusters to shoot for a number.
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  12. Norman Foley

    Norman Foley Devotee of the Husqvarna Supporter

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    Typically if you have the incorrect spring for your weight, you'll only be able to get one of the two measurements correct when adjusting preload. If you have the right spring.... Presto!
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  13. heffergm

    heffergm Long timer

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    Yes, indeed I do. Hooray for me. They're rear measurements.
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  14. heffergm

    heffergm Long timer

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    Bingo.

    I think most new-ish riders would be a little surprised at how soft a correctly sprung rear shock on a trials bike is... I guess a lot of people tend to fall into the 165-185 sort of range that the standard springs typically suit, so it's not an issue for them, but that stock spring for me is a disaster.
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  15. 2whlrcr

    2whlrcr gooligan

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    Wouldn't that be closer to .75" in static? :D
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  16. heffergm

    heffergm Long timer

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    Only if I wrote 20mm, which was an accident. I meant 10mm. Edited. I've run 20mm before. It works, but it's a little dead for me. If you're on the lighter end of the spectrum for your spring though, it might be great. I'm on the heavy side for the spring I run.
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  17. lineaway

    lineaway Long timer

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    1.75 of Sag. Sorry, but any time I think of sag is with the rider. It does bewilder people because in a driveway it feels really good, but once you start bouncing off a bunch of rocks it kicks you around. For years it was very hard too find replacement springs sprung for other weights besides stock. We just rode the crap out of them.
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  18. 2whlrcr

    2whlrcr gooligan

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    Dammit, check your work. All hell could break lose if misinformation is posted on the internet.
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  19. Norman Foley

    Norman Foley Devotee of the Husqvarna Supporter

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    :photog
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  20. Brewtus

    Brewtus Buffoonery, Inc.

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    C'mon, spring!!!



    :hide
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