Author Topic: Spring rates  (Read 3229 times)

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  • Offline TwiggLe   us

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    Offline TwiggLe

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    Re: Spring rates
    Reply #10 on: Jun 22, 2022, 12.23 pm
    Jun 22, 2022, 12.23 pm
    *Originally Posted by Cazzy_R [+]
    Zed9 thoughtfully shared that his rear shock was re-sprung with a 700lb/in (120N/mm) for his riding weight of 200lb (90kg). Fork springs at .95N/mm
     I'm 250lbs (115kg) in gear and I wonder what spring rates would be correct for my weight?
     Are there any rider weight charts/tables for the Z900 out there?

    What specific parts did you end up going with?

    I'm just over 250 fully geared and was looking at the k-tech R lite rear (Part#:287SD-017-150-092), and then trying to find replacement springs to install on the front but wasn't sure what ones to get.

    Had a shop adjust my stock suspension last year but I think they just maxed the preload now I feel like I'm going to be launched off the bike on any decent bump.

  • Offline Cazzy_R   england

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    Offline Cazzy_R

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    Re: Spring rates
    Reply #11 on: Jun 22, 2022, 02.21 pm
    Jun 22, 2022, 02.21 pm
    *Originally Posted by TwiggLe [+]
    What specific parts did you end up going with?

    I'm just over 250 fully geared and was looking at the k-tech R lite rear (Part#:287SD-017-150-092), and then trying to find replacement springs to install on the front but wasn't sure what ones to get.

    Had a shop adjust my stock suspension last year but I think they just maxed the preload now I feel like I'm going to be launched off the bike on any decent bump.

     K-Tech didn't offer rider weight specific versions when I ordered my K-tech Razor-R.
     I gave my suspension supplier my rider weight and my Razor-R arrived with a 110N/mm spring (2 sizes stiffer than default).
     For whatever reason K-tech suggest a 120N/mm spring for the Razor-Lite and a 130N/mm spring for the Razor-R, at our weight, so I'm a little suspicious of their numbers. The 110N/mm spring works well for me but I think a 120 would be better still. The part number you quoted comes with a 120 spring so I think you will be good there.
     
     I went a different way on the front with a Maxton single leg cartridge which leaves the standard "spring only" unchanged. The Maxton leg has 1.05N/mm spring rate, According to K-tech the remaining "spring only" leg has a .85N/mm spring. So that averages out at 0.95N/mm. The Maxton cartridge is wonderful no complaints what so ever but last I heard not available on your side of the pond.
     I'm not sure upping the spring rate alone, up front will help much without some attention to the damping.
     Hope that helps.
     
     
    Last Edit: Jun 22, 2022, 02.22 pm by Cazzy_R
    Tighten it 'til it strips then back it off half a turn.

  • Offline zed9   us

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    Offline zed9

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    Re: Spring rates
    Reply #12 on: Jun 22, 2022, 04.12 pm
    Jun 22, 2022, 04.12 pm
    *Originally Posted by Cazzy_R [+]
    K-Tech didn't offer rider weight specific versions when I ordered my K-tech Razor-R.
     I gave my suspension supplier my rider weight and my Razor-R arrived with a 110N/mm spring (2 sizes stiffer than default).
     For whatever reason K-tech suggest a 120N/mm spring for the Razor-Lite and a 130N/mm spring for the Razor-R, at our weight, so I'm a little suspicious of their numbers. The 110N/mm spring works well for me but I think a 120 would be better still. The part number you quoted comes with a 120 spring so I think you will be good there.
     
     I went a different way on the front with a Maxton single leg cartridge which leaves the standard "spring only" unchanged. The Maxton leg has 1.05N/mm spring rate, According to K-tech the remaining "spring only" leg has a .85N/mm spring. So that averages out at 0.95N/mm. The Maxton cartridge is wonderful no complaints what so ever but last I heard not available on your side of the pond.
     I'm not sure upping the spring rate alone, up front will help much without some attention to the damping.
     Hope that helps.
    If you have averaged a .95 at 250 pounds you have improved the situation but I think youíre still falling short.
    I have a .95 rate and Iím a meager 205 lb fully geared. And at .95 Iím using nearly all my front travel according to my zip-tie while street riding (which is what you want). If I were a track rider my guy would have installed 1.0 springs.

    Itís one or the other. If you want stiffer springs for the track then youíll have a harsher ride on the street and wonít be using the full travel that you paid for. At .95 and 250 pounds youíll be using all your travel. Install a zip-tie to check it.

  • Offline Cazzy_R   england

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    Offline Cazzy_R

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    Re: Spring rates
    Reply #13 on: Jun 22, 2022, 04.38 pm
    Jun 22, 2022, 04.38 pm
    *Originally Posted by zed9 [+]
    If you have averaged a .95 at 250 pounds you have improved the situation but I think youíre still falling short.
    I have a .95 rate and Iím a meager 205 lb fully geared. And at .95 Iím using nearly all my front travel according to my zip-tie while street riding (which is what you want). If I were a track rider my guy would have installed 1.0 springs.

    Itís one or the other. If you want stiffer springs for the track then youíll have a harsher ride on the street and wonít be using the full travel that you paid for. At .95 and 250 pounds youíll be using all your travel. Install a zip-tie to check it.

     I get what your saying but I'm totally happy with the front end and as far as I'm concerned the numbers are only a guide. Comparing spring rates without knowing how one another ride or where we ride or what our respective suspension suppliers have done with valving, pre-load, air gap and oil weight isn't going to tell us that much.
    I fiddled about with the back because I always feel it can could be better but the front is untouched and will stay that way and I won't be measuring or twisting anything. No offence meant but I'm blissfully happy with the front and my only regret is working out the average spring rate for the sake of s forum post. :821:
    Tighten it 'til it strips then back it off half a turn.

  • Offline zed9   us

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    Offline zed9

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    Re: Spring rates
    Reply #14 on: Jun 22, 2022, 04.52 pm
    Jun 22, 2022, 04.52 pm
    *Originally Posted by Cazzy_R [+]
    I get what your saying but I'm totally happy with the front end and as far as I'm concerned the numbers are only a guide. Comparing spring rates without knowing how one another ride or where we ride or what our respective suspension suppliers have done with valving, pre-load, air gap and oil weight isn't going to tell us that much.
    I fiddled about with the back because I always feel it can could be better but the front is untouched and will stay that way and I won't be measuring or twisting anything. No offence meant but I'm blissfully happy with the front and my only regret is working out the average spring rate for the sake of s forum post. :821:
    If youíre happy, Iím happy. 🍻