How to increase front suspension travel

Discussion in 'The Garage' started by bikecat, Apr 21, 2012.

  1. bikecat

    bikecat Long timer

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    Hi,

    The front travel of my Megamoto is only about half of the available travel. How do I go about making use of the available travel? Common sense dictates using a lighter weight fork oil, and increasing the length of the air column. Am I right or is there something I overlooked?

    The forks have rebound and compression adjustments, but no preload adjustment at the top.

    Cheers
    #1
  2. kpt4321

    kpt4321 Long timer

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    Careful. Lighter oil will decrease damping, which ay not be what you want.

    Lower oil level is a good idea, and I would investigate if the stock spring rate is appropriate for your weight.
    #2
  3. stainlesscycle

    stainlesscycle Long timer

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    you could very well have forks bound up. makes forks harsh, and eliminates travel...

    loosen all axle pinches
    tighten left side pinches only
    bounce front end a couple of times
    apply front brake, compress forks as far as you can
    (this takes 2 people usually) with the forks as far down as you can push them down tighten right side axle pinches

    bounce forks and see if travel is back...
    #3
  4. HapHazard

    HapHazard Waiting for Gudenov

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    From what I've seen, the Megamoto has 6.3" of front end travel. To use ALL of the available travel would require a hellacious bump. Did you check the travel using a tie wrap loosely fitted to a fork stanchion, ride over gigantic bump, then stop and pull up on the front end to eliminate the sag and measure the distance the tie wrap has moved?

    Stainless' suggestion regarding bind is a good one, at any rate.

    You may not have a problem. The only street bike I ever bottomed the fork on (used all the travel) is my Sportster.
    If you want to trade, let me know!:lol3
    #4
  5. bikecat

    bikecat Long timer

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    Hiya, appreciate the help here.

    Here's a pic of the fork with the travel used over various bumps etc, compared with the available travel.

    [​IMG]

    Unfortunately the MM does not come with preload adjuster. How does one adjust the sag in this case? By varying the oil's weight and air-gap?

    Cheers
    #5
  6. PeterW

    PeterW Long timer

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    Change the springs is usually the answer to that, though check what the % sag is - it should be around 30% of total travel with you on the bike. If it's a lot less, check the spacers inside the fork - you MIGHT get away with shorter spacers. You need some room for the wheel to drop i.e. potholes and to cope with rebound 'bounce'. For a linear system that's optimally damped (fastest settling) the rebound is around 30%.

    If the spec. travel is 6.5" and you've used 5.5" that'd be doing pretty well, you usually want some reserve for "bad shit just happened".

    Changing the oil shouldn't help unless it's far to heavy now - if that's the case the front of the bike will sink lower and lower if you go over a series of bumps - that's usually pretty noticeable because of the bad effect it has on handling.

    Pete
    #6
  7. Twin-shocker

    Twin-shocker Long timer

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    If you want to have the full travel available, then dismantle the forks and fit pre-load spacers which eliminate all sag, or stronger springs if longer spacers wont work. The bike will then be pretty much unrideable, as the suspension wont move on anything other than very large bumps, but you will have full front suspension travel.
    #7
  8. HapHazard

    HapHazard Waiting for Gudenov

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    I'm with Pete, you're just about right where I'd want to be for travel and have a margin for the "Oh, Shit!" bumps.

    Don't worry, be happy, and if you want to trade, the offer stands.:D
    #8
  9. kpt4321

    kpt4321 Long timer

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    Unless you were racing the bike or jumping it, using 5.5 inches out of 6.3 inches is pretty good. Depending on how hard and how long you rode it to accomplish that, I might even be inclined to say it's too soft.

    I don't understand why you said you are only using half of the available travel, if you are using 5.5 out of 6.3 inches.
    #9
  10. FlyingFinn

    FlyingFinn Long timer

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    One thing to keep in mind that the suspension travel numbers on the Mfg spec sheets are.... should I say optimistic.
    I'm sure they aren't quite lying but what they often give is a number that's "metal to metal" at both ends of the suspension travel.

    The forks have a top-out spring. To get the full 6.3" of travel (if that what the Mfg spec is) you'd need to go from a fully compressed top-out spring to forks compressed to full compression stop.

    --
    Mikko
    #10
  11. Beezer

    Beezer Long timer

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    only thing left to add is.... increasing the air column will make the ride softer and increase the brake dive
    #11
  12. bikecat

    bikecat Long timer

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    Thanks for the words of wisdom (and of doom) :)

    I tweaked with the oil weight and ended up with the same travel but seemingly (psychological??) plusher front end. However, at slow speeds the front still seem "jittery" but at higher speeds (70km/up upwards) I'm happy.

    What you guys reckon? I am thinking increasing rebound and compression by 2 clicks to temper the jitters.

    Views?
    #12