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Ride height new fork springs

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    Ride height new fork springs

    I just replaced the old, (probably) original progressive fork springs with RaceTech .90 springs. At the same time, I went from almost 30 psi to zero.

    I would have expected the new springs to raise the bike, but I think it's sitting lower: I used to be able to put two bricks under the side stand, and while it was close to vertical, it would still lean on the stand. With two bricks now, it'll fall to the right.

    I did also, at the same time replace both tires, but I wouldn't think that would make much of a difference. Damping is at 1, spring preload is lowest, but I'm not sure what they were before.

    Any thoughts on this?
    1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

    2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

    #2
    What length spring spacer did you use? What length did RaceTech recommend?


    Life is too short to ride an L.

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      #3
      How much laden sag do you have? That is with you in full gear sitting on the bike. You want to be around 25% of the total travel for most street use. The 0.90 springs are pretty soft for the 1100E unless you are very light so you may end up a bit over 25% of travel unless you heavily preload the springs.


      Mark
      1982 GS1100E
      1998 ZX-6R
      2005 KTM 450EXC

      Comment


        #4
        Originally posted by mmattockx View Post
        How much laden sag do you have? That is with you in full gear sitting on the bike. You want to be around 25% of the total travel for most street use. The 0.90 springs are pretty soft for the 1100E unless you are very light so you may end up a bit over 25% of travel unless you heavily preload the springs.


        Mark


        Agreed. "Number of bricks" is totally irrelevant. Static sag (AKA "laden sag") with you on the bike, not just the bike on the kickstand, is what matters. Fine-tune spacer length to achieve the proper sag.

        30psi is a hell of a lot of air pressure in forks, so they may have been extended all the way previously when on the kickstand with no rider.
        1983 GS850G, Cosmos Blue.
        2005 KLR685, Aztec Pink - Turd II.3, the ReReReTurdening
        2015 Yamaha FJ-09, Magma Red Power Corrupts...
        Eat more venison.

        Please provide details. The GSR Hive Mind is nearly omniscient, but not yet clairvoyant.

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        Comment


          #5
          Dumb questions but... Did the aspect ratios and section widths remain unchanged? Are they the same brand/model tires?

          Comment


            #6
            Originally posted by bwringer View Post
            Agreed. "Number of bricks" is totally irrelevant.
            30psi is a hell of a lot of air pressure in forks, so they may have been extended all the way previously when on the kickstand with no rider.
            Number of bricks tells me something is different. 30 psi was used as a temporary band-aid to keep the forks from bottoming out until the new springs arrived.

            Originally posted by rudeman View Post
            Dumb questions but... Did the aspect ratios and section widths remain unchanged? Are they the same brand/model tires?
            Tires are new and different, but same size.

            I used to tell my students, "there's no such thing as a dumb question." Not because that's always true, but to encourage them to ask.

            Thanks for your encouragement.
            1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

            2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

            Comment


              #7
              Sounds like your spacer is too short or did you even install one? When I installed my .95kg Sonic springs and cut to length spacer material supplied (with 20w fork oil zero air), my ride height was raised a tad though doesn't feel like it. Kind of agree, .90kg springs seem a bit soft. 30 psi before the new springs? Sounds like way to much air, most I've seen is 7 to about 12psi in the forks, anything more then that it blows right past the fork seal.
              Last edited by mrbill5491; 08-21-2014, 07:38 PM.
              sigpicMrBill Been a GSR member on and off since April 2002
              1980 GS 750E Bought new in Feb of 1980
              2015 CAN AM RTS


              Stuff I've done to my bike 1100E front end with new Sonic springs, 1100E swing arm conversion with new Progressive shocks installed, 530 sprockets/chain conversion, new SS brake lines, new brake pads. New SS fasteners through out. Rebuilt carbs, new EBC clutch springs and horn installed. New paint. Motor runs strong.

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                #8
                The manual recommends 7.1 psi, and says never to use more 36. I'm running zero now psi now.
                1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

                2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

                Comment


                  #9
                  Originally posted by Rob S. View Post
                  The manual recommends 7.1 psi, and says never to use more 36. I'm running zero now psi now.
                  The reason you are repeatedly told to not use air is because you will have a constant balancing problem keeping air pressure the same. Instead just customize the spring for your weight and riding style and be done with the past. It was a Production crutch to span a wide range of riders with a single spring.
                  Last edited by posplayr; 08-21-2014, 08:58 PM.

                  Comment


                    #10
                    IIRC, there's only one air inlet. I might be wrong, I'm looking at two "air joints" in the diagram now.

                    Update: I think the air only goes in the left side(sitting on the bike).
                    Last edited by Rob S.; 08-21-2014, 09:09 PM.
                    1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

                    2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

                    Comment


                      #11
                      Originally posted by Rob S. View Post
                      IIRC, there's only one air inlet. I might be wrong, I'm looking at two "air joints" in the diagram now.
                      Yes on the 82-83 1100e there is a cross over pipe to equalize pressure but that doesn't keep it from leaking. Springs take a lot longer to leak.

                      Comment


                        #12
                        Originally posted by posplayr View Post
                        Springs take a lot longer to leak.
                        I hate when that happens!
                        1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

                        2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

                        Comment


                          #13
                          As has been said, 30psi was a lot and it reduced your sag. What is was though really doesn't matter, just set your total sag to ~35mm and all will be well.

                          Also, if the tires are a different brand and/or model they won't be exactly the same diameter even if the nominal size is the same.
                          '20 Ducati Multistrada 1260S, '93 Ducati 750SS, '01 SV650S, '07 DL650, '01 DR-Z400S, '80 GS1000S, '85 RZ350

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