12" shocks on RK possably change oil?

Discussion in 'Touring Models' started by baust55, Nov 19, 2011.

  1. baust55

    baust55 Member

    GREETINGS i am new on this forum.I am from s.e. nebraska

    Ok i got a cpl questions for you internet experts .

    how many of you have expermented changing to diffrent oil weights in shocks to tune them ?

    I own a 2008FLHRC i wanted to lower the rear one inch but most lowering blocks will not work with the leather wrapped bags . so i bought a pair of 12" low touring shocks from ebay OEM part #54662-02A low.

    i know my stock 2008 13" air shocks take max presure 35psi . I understand the 09 and newer shocks take 50psi max . so how do i determine if the shocks i bought are 09 newer or older ? does the part # tell ? also is the max presure diffrence due to the the airlines ect on the bike or the shocks ?

    i am asuming theses shocks have the 5w stock oil i am debating wether to put them on this way or change out to 7w oil . i weigh 190lb.

    the seller said the shocks were installed on a 2007 electra glide for a short time .. but didn't know if it was recently "newer shocks " or not .

    Now if i change the oil i know the 13" shocks take 10.5 oz oil .do the 12" shocks take the same amount ?

    how will alteering the amount of oil in each shock a few onces alter the ride?

    Attached Files:

  2. dbmg

    dbmg Experienced Member

  3. baust55

    baust55 Member

    hey thanks for the info .. i am just trying to gather info during the off riding season before i change my shocks
  4. oiler

    oiler Active Member

    Here is some info that may help you and others that may be considering changing their shock oil. I have a 2009 SG with the stock 12”shocks – HD part # 54662-09. I don’t know if these are internally the same as the ones you bought. Anyway I got exactly 10.5 oz out of each one. I sent a sample of this oil to Bel-Ray to run a visc test @40c. The tech service manager agreed to do this for free so what the heck. I know everyone says that the oil is a 5wt but the visc @40c differs from brand to brand.

    The visc of my sample came in @ 17.1. If you go to Bel-Ray’s web site and look at their HVI Racing Suspension Fluid chart, their 5wt oil’s visc @40c is 18.5. So it is roughly a 5 wt oil. By the way the tech service manager does not recommend using fork oil in a shock absorber. He says the HVI Racing Suspension Fluid has different additives in it that are made for shock absorbers.

    I mixed 50/50 - 5wt and 10wt of Bel-Ray’s Racing Suspension Fluid. This mixture gives a visc @40c of 24.9 using their chart and that is roughly just under a 7.5 wt.

    I weigh 180lbs and my owners manual says to set the shock air psi 0-10 psi (solo & no tourpak) I used to set it at 10 psi but now after the oil switch I set it around 7psi.

    Hope this helps.
  5. baust55

    baust55 Member

    hey thanks for the interesting info