Changing springs in Big Piston Forks

Discussion in 'Mods, Upgrades, Accessories and Products' started by RedMacGregor, May 22, 2013.

  1. RedMacGregor

    RedMacGregor Active Member

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    I know a few people on this forum have had their fork springs changed to better suit their weight but has anyone changed the springs in BPForks? I'm trying to work out if it's possible to change them without removing the forks from the bike. It looks possible as everything connected to the spring seems to come out with the top cap. The reason I ask is I'm miles too light to get the forks working correctly so a change to a lighter spring would really improve matters.

    Any useful comments would be welcome.

    Thanks - Steve
     
  2. sinewave

    sinewave God Like

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    I'd take some advice from a Sussie Specialist before you start feckin' about with no experience.

    I have the BPF in mine and have had them set up by a specialist.

    They said the BPF are very good and very adjustable so unless you weigh as much as a ten year old child you should find they can be set up to suit you just fine.
     
  3. RedMacGregor

    RedMacGregor Active Member

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    I think you'll find the front suspension is reasonably straightforward to work on mate the problem is sometimes you need specialist tools. The tools to do this job would cost around £50 so cheaper than paying someone to do the work. I know I can change the springs with the forks off the bike and I think possibly on the bike - hence the post.

    I would agree to get them setup correctly you might need the assistance of a suspension expert. In my case I had the suspension setup at a track day a couple of weeks back. The stock springs in 2012 forks BPFs are ideally suited for a 13 stone rider. I only weigh the same as a ten year child so consequently no amount of adjusting will cure the problem because the springs are too stiff preventing the full use of all the available movement.
     
  4. JM1

    JM1 Active Member

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    Regardless of how adjustable they are (I think they're referring to damping adjustment anyway), they still contain springs, which are designed for a certain weight range.
     
  5. RedMacGregor

    RedMacGregor Active Member

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    Just had an e-mail from K-Tech - they advise changing the spring from the stock 11Nm to a softer 9.5Nm spring. This should suit my weight much better. £85.00 for a spring - just trying to get a price for the two spanners needed to do the job.
     
  6. foenix

    foenix Active Member

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    And what s your weight ?

    I'm 86 kg and with 1kg and ohlins niw30 it always a little stiff.

    i ll try 0.950kg
     
  7. PeterT

    PeterT Active Member

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    Standard Springs are around 11NM, I am going to change mine as I did with my 2010 model to 9.5NM which suits my weight at around 86KG. Again it's having the top spanner which is what I do not have as I changed the springs on my old model (pre big piston forks). I also used K-Tech springs which where great.
     
  8. PeterT

    PeterT Active Member

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    Also change the oil to a synthetic brand at a 30 weight oil.
     
  9. foenix

    foenix Active Member

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    Yes i ll try 0.950 in my Ohlins fork this week.

    At the beginning i belive that was my rear spring was too soft = more weight on the rear. But on the end, my rear spring is good ,10.5 Ohlins, i 'm using all the track of the shock less 0.8 cm or less.

    What dou you have on your rear ?
     
  10. RedMacGregor

    RedMacGregor Active Member

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    Just noticed the new posts foenix - I'm around 75Kg so close enough to your weight. I've fitted the springs now and the bike is much less harsh on bumpy roads. I went for the quick option and left the forks in situ as the oil is pretty new. I'm still experimenting with suspension settings as I'm sure there is still room for improvement.
     

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