Fork Spring Dimensions

Discussion in '6th Generation 2002-2013' started by BigRocketMan, Aug 26, 2021.

  1. BigRocketMan

    BigRocketMan New Member

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    Hi all,

    I want to install some .95kg linear fork springs in my 07 6th Gen and Eibach springs, who is close by, asked me for Dia and Length.
    I haven’t removed the stock springs yet but being progressives they wouldn’t be anything to go off.

    So please does anyone who know what Dia and Length linear springs I’d be asking for? Many thanks.
     
  2. raYzerman

    raYzerman Insider

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    I don't have one, but the service manual will give a length. Shouldn't matter if a bit different, as I expect you'll cut new spacers anyway.
     
  3. Diving Pete

    Diving Pete Member

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    I have a set of uprated springs to be installed on my 08. I was told that i will need to make 2 spacers & to make the air gap the same. Happy to get the dimensions for you.
     
  4. BigRocketMan

    BigRocketMan New Member

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    That would be great thanks.
    BTW so long as yours are linear variety…
     
  5. Diving Pete

    Diving Pete Member

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    I'll take a look later tomorrow, & update then.
     
  6. Terry Smith

    Terry Smith Member

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    The stock spring length is given as 334mm in the service manual. The OD would be 37mm I believe.
     
  7. BigRocketMan

    BigRocketMan New Member

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    Many thanks. However the stock ones are progressive with a lot more installed preload so the length won't suffice when looking at linear type.
     
  8. raYzerman

    raYzerman Insider

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    Any aftermarket springs for the bike will be appropriate and may have a different length than stock... if they're longer, you make or cut your spacers to suit... usually so there is 15mm of preload when you try to re-install the fork caps with any preload adjusters backed right out. Fork oil level should be a touch lower than stock to give more air cushion for say straight rate springs, you can vary this but never put oil higher than the stock level.
    If you find later that you don't have enough preload, easy enough to install some washers or make new spacers. Not likely though with straight rate springs of the proper spring rate for your weight.
     
  9. BigRocketMan

    BigRocketMan New Member

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    Got it. Makes perfect sense :O)

    I'm using 10W oil for .95kg linear type. Hopefully that'll go well !!
     
  10. Diving Pete

    Diving Pete Member

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    Mine are linear, 315mm x 37mm, srpring rate - .90.. Looking forward to fitting them. I only weigh 145 so these should work well for me. They are, if I can remember Racetech springs.
     
    Last edited: Aug 28, 2021
  11. BigRocketMan

    BigRocketMan New Member

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    Cheers for the contributions.

    After selling my 2005 VFR then owning a 2011 Street Triple and a 2006 FZ1 they are just boring bikes imo, especially the latter.

    I'm picking up a 2007 VFR tomorrow as these are special bikes. They may be a bit porky on the scales but overall are excellent, unique and without pier ;O)
     
  12. raYzerman

    raYzerman Insider

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    Just to add some perspective I've had on other bikes. The spring rates for our weights is the same no matter which bike it seems, heavier or same weight as a VFR or CBF.... RaceTech's rates seem about right, however, in the case of an FJR, Traxxion has a plug and play kit they give to everyone regardless of weight, and it has 1.1 spring rate. One would think that a tad high for a 200 lb. guy, but it's not. I installed them at the insistence of a 170 lb. guy on his FJR, we backed the preload adjusters almost right out, and I believe we used an oil height of 140mm (stock height is 100mm). Substantial air volume... I followed up with him a few times and he reported it was awesome. Caveat too, that bike has both adjustable compression and rebound on the forks should one need to alter the damping.

    I have 1.0 springs in my Gen 5, and I used 10W oil. It's fine. On the CBF, I have 1.0 springs and 15W oil because it needed more damping to tame it down. Had to make 20mm longer spacers to add more preload also, it has no adjusters.

    Basically, I think if your spring rate is higher than the RaceTech chart, that's OK, just lower the fork level a bit..... no harm in the front end being a bit harder and stable. You'll get it after a season of riding and can decide if that needs tweaking with oil weight or air gap.... changing the air gap though is not a real significant change unless you change it by a lot.
     
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