Progressive fork springs

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  • BuickWildCat
    XSive
    • Mar 2012
    • 12
    • Wind Lake, Wisconsin

    #1

    Progressive fork springs

    Since I've got the XS11 running again it seems like there is a lot more dive when I hit the brakes than I remember. The fork fluid has been changed so I was wondering how well progressive fork springs work?
    Thanks,
    Mark
  • crazy steve
    XS-XJ Guru MODERATOR
    • Jan 2009
    • 7932
    • Beautiful outer Yelm, WA

    #2
    Progressive springs will help with that, but are you sure everything is right with your forks? Filling them with the right amount of oil is critical, did you try adjusting the preload, if you have air forks did you try more air?

    You can also 'tune' the forks by changing fork oil weight and amount, I've had good luck with that.
    Fast, Cheap, Reliable... Pick any two

    '78E original owner - resto project
    '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
    '82 XJ rebuild project
    '80SG restified, red SOLD
    '79F parts...
    '81H more parts...

    Other current bikes:
    '93 XL1200 Anniversary Sportster 85RWHP
    '86 XL883/1200 Chopper
    '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
    Cage: '13 Mustang GT/CS with a few 'custom' touches
    Yep, can't leave nuthin' alone...

    Comment

    • New2Me
      XSive
      • Jun 2011
      • 91
      • Morris, IL.

      #3
      Originally posted by crazy steve
      Progressive springs will help with that, but are you sure everything is right with your forks? Filling them with the right amount of oil is critical, did you try adjusting the preload, if you have air forks did you try more air?

      You can also 'tune' the forks by changing fork oil weight and amount, I've had good luck with that.
      I thought when the progressive springs are added you do not add air to your shocks? At least that is what someone on here told me last year. I never followed up with how much oil to add though.
      1980 XS1100G
      -4:2 exhaust
      -Pods
      -Who knows what the future holds..

      Comment

      • WSL91
        XStremely XSive
        • Feb 2012
        • 427
        • Quad Cities, IL

        #4
        Originally posted by BuickWildCat
        Since I've got the XS11 running again it seems like there is a lot more dive when I hit the brakes than I remember. The fork fluid has been changed so I was wondering how well progressive fork springs work?
        Thanks,
        Mark
        I just made a set of spacers for my springs and they stopped the diving. I made them 3/4" as I have a Windjammer. I'd guess they are too stiff without the WJ
        1970? Honda Z50... gone
        1974? Yamaha 100 Enduro... gone
        1974 Honda CB200... gone
        1981 Yamaha Virago 750... gone
        1993 Honda Shadow 1100... gone
        2008 Honda VTX 1800F
        1982 Yamaha XJ1100J w/850 final, Raptor ACCT
        1979 Yamaha XS1100SF "Chewey" Raptor ACCT

        http://www.johnsoldiron.com

        Comment

        • crazy steve
          XS-XJ Guru MODERATOR
          • Jan 2009
          • 7932
          • Beautiful outer Yelm, WA

          #5
          Originally posted by New2Me
          I thought when the progressive springs are added you do not add air to your shocks? At least that is what someone on here told me last year. I never followed up with how much oil to add though.
          Yes, Progressive recommends that you not add air with their springs. But what I was trying to get across is that with some tuning, sometimes you can improve what you have for little or nothing. The air-assist forks aren't the best candidate for this as the springs are a bit soft, but using a bit thicker fork oil will help with dive.

          I rebuilt a set of H air forks, swapped the springs for a set of early non-air springs and added 10cc of extra oil and they worked great...
          Fast, Cheap, Reliable... Pick any two

          '78E original owner - resto project
          '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
          '82 XJ rebuild project
          '80SG restified, red SOLD
          '79F parts...
          '81H more parts...

          Other current bikes:
          '93 XL1200 Anniversary Sportster 85RWHP
          '86 XL883/1200 Chopper
          '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
          Cage: '13 Mustang GT/CS with a few 'custom' touches
          Yep, can't leave nuthin' alone...

          Comment

          • motoman
            Master of XSology
            • Aug 2005
            • 8413
            • Grand Junction, Colorado

            #6
            Over the years of use, the orfices get larger(forks can get hot, and that is friction from the oil), so to compensate for that use a QUALITY 15w fork oil of your preference. Mine just happens to be Silcolene.
            81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top.

            Comment

            • jetmechmarty
              Master of XSology
              • Nov 2003
              • 7765
              • Coldwater, Mississippi

              #7
              Heavier viscosity oil will slow them in compression rebound. More oil in the forks (less air space) will keep them from bottoming out.
              Marty (in Mississippi)
              XS1100SG
              XS650SK
              XS650SH
              XS650G
              XS6502F
              XS650E

              Comment

              • BigRed
                XStremely XSive
                • Mar 2010
                • 265
                • Ottawa, Ontario, Canada

                #8
                I bought progressive springs and rear springs & shocks, and I'm happy with them. I didn't put air in the forks with the progressives; just used the spacer length they recommended. They included the spacer material, I just had to cut it. My only disappointment is that I opted for HD springs for the rear because I'm a heavy guy, but I always have it on the lightest setting and find it stiff unless I have a passenger. I think the regular springs for the rear would have been good enough, and I could have stiffened them up when I had a passenger.
                '80 SG with motor from a '82 XJ

                Comment

                • jetmechmarty
                  Master of XSology
                  • Nov 2003
                  • 7765
                  • Coldwater, Mississippi

                  #9
                  Originally posted by BigRed
                  My only disappointment is that I opted for HD springs for the rear because I'm a heavy guy, but I always have it on the lightest setting and find it stiff unless I have a passenger. I think the regular springs for the rear would have been good enough, and I could have stiffened them up when I had a passenger.
                  I guess that shows how subjective this is. I put heavy duty springs on mine and it wasn't enough. (I'm 225#) It was hitting the exhaust or center stand in the turns. I now have 140/200 rate and that was the cure. Next time I'll go with straight rate as I did on the front and get a better ride.
                  Marty (in Mississippi)
                  XS1100SG
                  XS650SK
                  XS650SH
                  XS650G
                  XS6502F
                  XS650E

                  Comment

                  • motoman
                    Master of XSology
                    • Aug 2005
                    • 8413
                    • Grand Junction, Colorado

                    #10
                    Originally posted by jetmechmarty
                    Heavier viscosity oil will slow them in compression rebound. More oil in the forks (less air space) will keep them from bottoming out.
                    First part true as far as compensating for enlarged orfices...................second part, true to an extent. A hydraulic lock is more likely.
                    81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top.

                    Comment

                    • jetmechmarty
                      Master of XSology
                      • Nov 2003
                      • 7765
                      • Coldwater, Mississippi

                      #11
                      A hydraulic lock is more likely.
                      I'm using a Race-Tech tuning guide. I'm sure I 'm leaving enough space. You are right. No space=hydraulic lock
                      Marty (in Mississippi)
                      XS1100SG
                      XS650SK
                      XS650SH
                      XS650G
                      XS6502F
                      XS650E

                      Comment

                      • Poprock
                        XSive Maximus
                        • Apr 2005
                        • 594
                        • Oregon Coast

                        #12
                        I have a fairing. Set up using 15 wt fork oil. Had a rough ride, dive on braking. I swapped out the 15 wt to ATF @ 7# air. Ride is a lot smoother, dive is about the same. Tire inflation is crucial too. Running max sidewall number less 10%. May add 5% back. Full inflate with single rider made a lot of vibration. Lose 4# and the tire works better. Felt a little slippy on some turns yesterday, so I'll try a little more air next time out.
                        1980 XS 11 Special: The King of Kong, 9th wonder of the world. Pacifico fairing, chopped shield, Yamaha hard bags, Diamond seat, T-Kat fork brace, XJ top end, YICS Eliminator, '80 carbs from Spyder Cycle Works, K&N Air filter, Fuse block, stainless steel valves & reg/rect from Oregon MC Parts. Raptor CCT, XJ air shocks, 850 FD, Sportster mufflers, Standard handle bar, Tusk Bar Risers, SS braided brake lines. Cat Eye speedometer. HID projector beam headlight, LED running lights.

                        Comment

                        • motoman
                          Master of XSology
                          • Aug 2005
                          • 8413
                          • Grand Junction, Colorado

                          #13
                          Originally posted by Poprock
                          I have a fairing. Set up using 15 wt fork oil. Had a rough ride, dive on braking. I swapped out the 15 wt to ATF @ 7# air. Ride is a lot smoother, dive is about the same.
                          Imagine it would be.........ATF is NOT a dampening oil.......old school and works in a pinch...that's bout the extent of it.
                          81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top.

                          Comment

                          • Poprock
                            XSive Maximus
                            • Apr 2005
                            • 594
                            • Oregon Coast

                            #14
                            Motoman, I bow to your experience and expertise. No desire at all to jack this thread or to start another oil war. However I am curious about the molecular differences between a dampening oil and one that isn't. Can you help me out with that?
                            1980 XS 11 Special: The King of Kong, 9th wonder of the world. Pacifico fairing, chopped shield, Yamaha hard bags, Diamond seat, T-Kat fork brace, XJ top end, YICS Eliminator, '80 carbs from Spyder Cycle Works, K&N Air filter, Fuse block, stainless steel valves & reg/rect from Oregon MC Parts. Raptor CCT, XJ air shocks, 850 FD, Sportster mufflers, Standard handle bar, Tusk Bar Risers, SS braided brake lines. Cat Eye speedometer. HID projector beam headlight, LED running lights.

                            Comment

                            • Elevener
                              XSive Maximus
                              • Jul 2009
                              • 608
                              • small town in TEXAS

                              #15
                              I have heard the atf thing many times, some even mix it with MMO, to me specific fork oil just doesnt cost that much.
                              Trapped in time. Surrounded by evil. Low on gas.

                              1980 XS1100G 1179 kit, Tkat brace, progressive springs & shocks, jardine spaghetti, Mikes coils, Geezer's rectifier

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