New fork springs - what should i get ?

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Alex_RO, Aug 28, 2012.

  1. Alex_RO

    Alex_RO Been here awhile

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    Hello,

    got a friend going over to the US and he's kind enough to bring back some stuff with him so... i'll be asking him to get me some stiffer springs.

    Details:

    Bike model:2007 Standard ADV (w ABS), standard .48 springs installed.

    Rider weight: 250 now but on a diet, aiming for ...let's say 230 (with gear, no luggage).

    Intended Usage: fast street and "fire" roads (these pretty much mean the same thing in Romania, you never know where you're gonna find a pothole), veeery little (and slow) offroad.



    I'm hoping to get away with .54 springs since anything thicker/heavier is going to required modifying the forks somehow and there's nobody around I'd trust to get that going (shipping the forks off to SPS isn't much of an option, i'm pretty much half way around the world). If there's a guide somewhere and a "kit" for installing heavier springs, i'd love to hear about it.

    Your thoughts? Should i get stiffer springs than .54 ? All input is welcomed.


    Thank you !!!
    #1
  2. henryroten

    henryroten Been here awhile

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    I have a 2011 R and originally went to .64 springs (with a Superplush revalve) and found that they were still to soft in hard braking and hard, rugged terrain. Went to ;70's and fixed the problem. Much better off road and particularly good on the street. The front end stays up and doesn't dive under hard braking.

    If you want to try the .64's let me know and I will try to figure out how to get them to you.
    #2
  3. offworlder

    offworlder Been here awhile

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    Weigh approx 175lbs. went with .64. Based on your weight, I'd say .64 should be your minimum.
    No modifications are required if using the right springs.
    #3
  4. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    The spring guide will need to be trimmed down for most springs of that rate, if you were having springs put in here at my shop I'd put in .68 front springs.
    #4
  5. Alex_RO

    Alex_RO Been here awhile

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    Since .70 seems to be the way to go... what modifications would be required for thicker springs ? Is there a guide somewhere ?

    Thank you, Alex
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  6. GZERO

    GZERO Fixing stuff around

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    Be carefull about hearing other peoples ideas on springs, you don't know how much weight his bike has and how much they weight.
    I'll say .70 for a heavy bike with a heavy rider, if not i'll go with the .68.

    BTW: i never done it, but .70 springs with stock valving seems crazy.
    #6
  7. Alex_RO

    Alex_RO Been here awhile

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    Yeah, doesn't seem particularly healthy to me either. I'm trying to find a solution to that... maybe a shop in Europe that can do the revalving.

    In the meantime, might as well try to get as much information as possible from the OC.

    Thank you, Alex
    #7
  8. mdfehrmann

    mdfehrmann Been here awhile

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    I'm 165lb's with gear, Safari tanks and running se springs .59's I think?
    Works great but my suspension is going to super plush over winter for S spec
    and valving.
    #8
  9. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    .70 is a very large increase over the stock .48kg springs. With the stock valving it won't be the best ride (not any worse than you are already experiencing). I'd recommend completing a revalve at the time of a spring swap as well, and would be more than happy to share a few stacks if you are capable of doing the work.
    The mid stroke is the major issue on these forks and needs to be addressed as well as the rebound valving when swapping to springs of this rate.
    Typically depending on the spring manufacture the I'd of the springs is too large therefore the spring guide needs to be trimmed down 1 to 1.5mm so the guide can travel through without any binding.
    #9
  10. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    This black spring guide needs to be trimmed down, just the ridges that guide it trough the spring itself.



    [​IMG]

    The midstroke harshness you feel (deflection) is due to the poor valving without enough float if you do not modify the midstroke tap and piston:

    [​IMG]

    These pictures are courtesy of KTMtalk.com located in the suspension form. These are not ADV forks, but very close in design.
    #10
  11. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    #11
  12. Yascher

    Yascher Been here awhile

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    Thats a great thread)))
    intresting to see what the end result will be
    #12
  13. slackmeyer

    slackmeyer Don't mean sheeit. .

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    That's not something I expected to hear. Didn't think that midstroke harshness was a problem on my stock forks, thought they were more likely to blow through the midstroke. Are you referring to adventure forks or SE forks?

    I wish I had time to try a bunch of different variations on forks, I think there's a lot of ways to skin this cat.
    #13
  14. syzygy9

    syzygy9 Been here awhile

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    I am struggling to see how an increase form the stock 0.48 to 0.70 is required. I had my own (2011 990 Adv) forks resprung to 0.56 with a revalve to suit - that's an ~17% increase in spring rate and it seems fine for my 85kg 'naked' + gear + load.

    On a recent trip across Australia with lots of fast and slow dirt roads (and some really gnarly sections) I am not aware of ever bottoming the forks but did use all of the suspension travel. Front and rear were set to 'max payload'; with no load this setting feels quite stiff.

    I am no suspension guru so happy to defer to the experts, but my understanding was that if you are using all of your travel and not bottoming, you're pretty close to the mark. Of course, if all you are doing is riding on smooth roads than compliance may not be your primary concern, rather things like fork dive under braking, and you can get away with much stiffer and less compliant forks.
    #14
  15. Alex_RO

    Alex_RO Been here awhile

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    Well.. there's no way I'm ever going to be under 200 pounds (hell, i might go back to 280 if i leave the exercise/diet thing) and i do end up on the slab a lot (i still wouldn't call romanian roads smooth). Might as well accept it and prepare for it. Either way, slab or offroad, it's still underspung.

    Now, I *might* have a way to send the forks to SPS without paying an obscene amount for shipping but it's not something definite so ... might as well learn as much as possible.


    Thank you, Alex
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  16. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    Bottoming control is not done via the springs, it is done by the air gap (air spring). This is why setting the oil level correctly on these forks is much more sensitive than smaller size dirtbikes.
    .48kg springs are very light, thats what we install in a 4 stroke ktm for riders who weigh in the range of 195 to 210 lbs, and this is on a ike that weighs around 230lbs less not including rider weight etc.
    #16
  17. Stumpalump

    Stumpalump Been here awhile

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    Springs keep the ride height in the position that the valve likes. There should be a spring chart but I have not seen one for the Adventure. You suspension tuners are like doctors and lawyers. Only tell them what they need to know. That's fine with me but it would be neat to see the recommended spring chart.
    #17
  18. Konflict Motorsports

    Konflict Motorsports KM TUNER

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    I wish there was a spring chart availible, its between my ears after years of R&D. We cant share everything as it is very easy for another company, someone to copy our valving mods, machine work, etc. Its how we make our living, the Raiders dont make their playbook public...
    #18
  19. GZERO

    GZERO Fixing stuff around

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    I'm in Venezuela, and i will get my suspension to superplush, but what i'm goin to do with the forks is open them up (not really hard), take the oil and the spring out and closed them, without the spring and the oil they weight less and you can packed them colllapse so they won't be as tall.
    Shipping back to you is another thing.
    #19
  20. Alex_RO

    Alex_RO Been here awhile

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    Shipping them back to me would be pretty much the same cost as the actual job. I just don't have that kind of funds available.

    If the "alternate" shipping method fails, I'll get the biggest pair of springs that don't required modifications, and run with that. It won't be the best option but it would be an improvement to the present setup.

    Thing is ... since i can't find anything remotely resembling a suspension tuner locally (most "tuning" involves switching to progressive springs and using thicker fork oil), i can't do the test/modify/test again procedure so i would prefer to get the forks to someone with a lot of experience, kind of a one-shot deal. We'll see if that works out.

    Thank you, Alex
    #20