R100GS rear spring rate

Discussion in 'Airheads' started by GTC, May 9, 2011.

  1. GTC

    GTC Been here awhile

    Joined:
    Oct 5, 2008
    Oddometer:
    298
    Location:
    Colorado Springs, Colorado
    I have looked all over and have not been able to find a shock spring rate calculator for an R100GS. I really like the ride of the stock shock and want to get close to the same spring rate on the next one I get. I am looking at a YSS shock that is set up for 165 pounds but have not been able to compare the spring rates because I can't seem to find the information. Please Help!

    Thanks George
    #1
  2. etj

    etj Adventurer

    Joined:
    Jul 28, 2001
    Oddometer:
    29
    Location:
    Woodinville WA
    Bruno of Bruno's Machine & Repair in Canada (who rebuilds R100GS shocks) tells me the stock rate is 7.5kg per mm which is around 420 lbs/in. Using published formulas and running the numbers, I calculate right about that too.

    I recently replaced my stock spring with a 600lb spring.
    #2
  3. R100RT Mark

    R100RT Mark Been here awhile

    Joined:
    Feb 19, 2011
    Oddometer:
    312
    Location:
    Georgia, USA
    Interested to know why you went with a 600lb spring and how the performance differs from stock? Thanks. Mark
    #3
  4. etj

    etj Adventurer

    Joined:
    Jul 28, 2001
    Oddometer:
    29
    Location:
    Woodinville WA
    I'm over 200lbs these days, and I have my 135lb wife on the back 75% of the time, and the stock spring was light to begin with. She and I together would bottom out a lot. Bruno suggested the 600lb and said he'd ridden that setup a lot himself. I bought the spring from him. He also provided a short spacer since the new spring is about 1/4 shorter than the one it replaces.

    I've only got a few miles on the new setup, all in the rain, so I've not done extensive testing yet. So far I like it. I need to get out for a few hundred miles and really thrash on it.
    #4
  5. R100RT Mark

    R100RT Mark Been here awhile

    Joined:
    Feb 19, 2011
    Oddometer:
    312
    Location:
    Georgia, USA
    Thanks for the added info. I'm 155 lbs and run solo, so we are coming at the spring rate from different angles. Mark
    #5