Rear suspension

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This topic contains 5 replies, has 0 voices, and was last updated by  Paul 15 years, 9 months ago.

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  • #97214

    Eric Smith
    Member

    A certain member here has asked how rear suspension is supposed to work/feel.

    This bloke is apparently a tad lazy so I am starting this thread on his behalf! :laugh:

    Here’s what I want from suspension (front and rear) and it is acheiveable with the right guy on the job:

    Most important is a plush feel in the initial part of the travel. I want to ride over the smaller rocks, roots, sharp lips or whatever without any deflection of the wheel from the path I choose or jarring through the bars. As a benchmark, I would say that I want to be able to ride over a branch as thick as my arm without any deflection or jarring – ideally wouldn’t even feel it! But then, that same suspension has to take the bigger hits like drainage banks without bottoming out. I can ride with plush suspension that has poor bottoming resistance, but it is slower and more tiring.

    You can gain a bit of plushness by running UHD tubes at lower pressures, although there is an increased risk of pinch flats and damage to rims. Depends where and how you ride. But this doesn’t solve the overall problem.

    Most trail riders will benefit from upgraded suspension, even if it is simply setting the sag (race and static) and having the clickers in the appropriate position.

    To set the clickers I usually find a shortish track with typical riding obstacles on it. Run the track once or twice before doing anything. Then I wind the clickers in the direction I (think) I want and usually go twice as far as I think I need. Then run the loop again. It is then easy to work out if it is better or worse, change clickers and repeat until you dial in the settings that work best for you. This is my method, and it works, but there may be better ways to do it!

    But just remember that all of the above is what I do, and this may be different for others.

    For the record, unless you weigh about 65kg, a DRZ400 comes from the factory with suspension (front and rear) that is simply inadequate. Apparently the forks on a WR250F are the same! If a DRZ owner, for example, has upgraded their forks, then wound the spring up on the rear, it will be too harsh in the initial part of the travel. This can be helped by the lower tyre pressures mentioned above, but this is a partial fix and has its risks! If someone was in that situation, I would recommend he remove the rear shock from the bike and get it to a good suspension guy. About $350 should see it spot on.

    Any others with good helpful advice please feel free to chime in as well. B)

    #153691

    Paul
    Member

    Firstly, you say you adjust the ‘clickers’ and ride again.
    Its better to do one clicker at a time say rebound, when that seems good move on to the compression one.
    If doing the forks treat the pair as one, same setting on both sides.

    Remember, a well setup bike usually needed work on the front as well as the rear to keep the whole bike well balanced.

    After owning the 06 model DRZ I feel the they are setup for a rider up to 85Kg from factory.
    Remember this is a trail bike sold as an enduro.
    Riders over 85Kg should look into re working the whole setup, front and rear as I did with good result and an invoice for $725.

    The rear shock needs oil changes when the forks are done at around every 3000Km.
    This will give noticable plushness back to the bike.
    If it is a new bike or a recently purchased second hand one this is the first thing I would recomend, then start again with the factory clicker settings.

    The rear shock can also be extended by 10 mm quite easily which improves the steering and ground clearance.

    The DRZ wears one of the shock bushes, the bottom one so check them both for play.

    Finally, if the shock is removed, check all the linkage bearings, swing arm bearings and the wheel bearings. There should be no noticable freeplay in any.

    #153743

    Eric Smith
    Member

    Good point Wikd, and of course that is what I do, but didn’t explain it very clearly I guess.

    Whatever the stock suspenders on a DRZ are set up for, it sure as hell wasn’t my fat can! :laugh:

    #153755

    Anonymous

    I’ve just been playing with my rear shock and found the method of going a bit farr with adjustment good as you can really see the effect. When you’re sure this is the way you want to go you can refine it the correct level to suit your style.

    Good advice ECKS :)

    #153923

    Bruce Curtis
    Member

    The job of rear suspension is to…

    *Keep the rear wheel in contact with the surface
    *Provide the rider with some degree of comfort, and control
    *Allow the bike to remain stable and ensure geometry doesn’t change too much through it’s arc of travel.

    It does this through the primary resistance of a coil spring and secondary resistance of Oil and Gas travelling through a series of restrictors to keep some control over spring compression speed, to stop “pogo stick” effect it also uses these very same oil restrictors to slow the rebound down as well. Most decent rear dampners/systems will have 4 points of adjustment
    Spring pre-load (sag)
    Shock Compression ajustability
    Low-speed rebound dampening
    High speed rebound Dampening, some elite systems also have adjustable ratios on their linkages but for the average trail rider this is a compromise betwixt $$$ outlay and returns.

    BC

    #153933

    Paul
    Member

    Post 2005 the DRZ shock has high and low speed comp damp clickers and one rebound clicker.

    Here’s a good article on setting the rear sag.

    rear sag setup method

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