Confused with progressive front springs GS1000E 1979

[gs79]

Awaiting an email back from Holland from the manufacturers for their comments. Meanwhile I will probably fit the forks and check the static sag and go from there

[bbjumper]

Unfortunately it does not mention anything at all about the spacer length. It just says fit the pre load bush

Check the manufacturers website, might be some help there but I would put a spacer in there to preload the spring otherwise you will have too much static compression.

[Nessism]

Most likely the instructions are in error. Assuming these springs are designed to work without air assist, then the springs should be roughly equal to the top of the extended legs before installing the caps. I'd try them with out any spacers then measure sag. Add a spacer as needed to get the proper amount of sag - I believe, about 25-30% with a rider sitting on the bike.

[Steve]

Cannot understand why these springs are 490mm in length compared to the standard 421mm springs surely there should not be any difference in length should there.

Did your stock setup have a spacer?

What was the total length of the spring (421mm) plus the spacer?

Any chance it's somewhere near the 490mm that you have now?

In other words, it probably hasn't changed much, just that it's all spring now, not spring and spacer.

The important thing to remember concerning 'preload': it is the amount of compression that you need to add to achieve the proper "sag" in the suspension.
"Sag" is the amount the suspension compresses from full extension to "ready-to-ride" height. You will need a helper to measure this, but check the length from the top of a fork tube to the bottom of the steering stem while the bike is on the centerstand and the forks are fully extended. Now have your helper measure the same area when you are on the bike, balanced on your tippy-toes, putting all of your weight on the bike. You want the suspension to compress about 20-25%. Most of our bikes have about 6 inches of fork travel, so that means 1 1/4 to 1 1/2 inches of "sag" is your target. If the bike drops more than that, add a spacer to get it back up. If it dropped 2 inches, add a 3/4 inch spacer, you will be close to that 1 1/4 inch figure.

By the way, you can do the same checks for the rear shocks to determine how much preload to add.

And, it is important to note that this assumes that you have the proper rate springs. Once you have your spring rates sorted out, it will be a simple matter of adjusting your fork oil viscosity to tune your damping, but that is for another thread.

.

[Agemax]

I really do not know if they are right for your bike.
I may have a solution for compressing them and tightening the cap.
!/2 inch drive socket extension with a 3/4 drive socket inverted and slipped up the extension one that you can get a really good grip on (deep-well).
Put your normal socket on the extension.
Push down force on the deep-well and tighten with other hand.
It can take a lot of force so be very careful you do not start to cross-thread.
I have used this technique on a few different bikes with great results.

they dont have a socket size nut on the fork tops, they are kind of oblong shape with the air valve screwed in. i would remove the air valve to prevent damage and you can only use a spanner to tighten them.

[Agemax]

you can measure the sag on the forks by putting a zip tie around the fork leg, quite tight, but not to tight to move. sit on the bike and push the zip tie so it sits flush with the top of the fork bottom. carefully get off the bike and put it on centrestand, front wheel off the ground.
then measure the gap between the zip tie and the top of the fork bottom

[Steve]

you can measure the sag on the forks by putting a zip tie around the fork leg, quite tight, but not to tight to move. sit on the bike and push the zip tie so it sits flush with the top of the fork bottom. carefully get off the bike and put it on centrestand, front wheel off the ground.
then measure the gap between the zip tie and the top of the fork bottom

That method can get you close, but I like to bounce the suspension a bit to remove any 'stiction' in the seals.

If you use the zip-tie and get on carefully, there might be just enough stiction (STatic frICTION) in the seals to prevent that last little bit of movement to the proper resting place. Bouncing a bit settles it in.

It is good for an estimate if you can't find a helper, though.

.

[gs79]

Many thanks for the replies guys I will fit the front wheel and measure the sag tomorrow and let you know.

[Agemax]

That method can get you close, but I like to bounce the suspension a bit to remove any 'stiction' in the seals.

If you use the zip-tie and get on carefully, there might be just enough stiction (STatic frICTION) in the seals to prevent that last little bit of movement to the proper resting place. Bouncing a bit settles it in.

It is good for an estimate if you can't find a helper, though.

.

bounce the forks, then reposition the zip tie.

[hampshirehog]

Sounds like you had GS1000S spec fork internals - 351mm springs and the standard S spacer of about 5 or 6 inches. Quite a few GS1000E bikes came (in the UK) with that set up as well. If you measure the springs that came out you'll know (service limit is 346mm)

Best follow the procedure for setting your forks up to your personal settings and how you like to ride.

[Steve]

Sounds like you had GS1000S spec fork internals - 351mm springs and the standard S spacer of about 5 or 6 inches.

Well, how about that.

If the springs were 351mm and you had a spacer that was just under 5 1/2 inches (5.47"), you would be right at that 491mm total length.

.

[gs79]

Sounds like you had GS1000S spec fork internals - 351mm springs and the standard S spacer of about 5 or 6 inches. Quite a few GS1000E bikes came (in the UK) with that set up as well. If you measure the springs that came out you'll know (service limit is 346mm)

Best follow the procedure for setting your forks up to your personal settings and how you like to ride.

Reckon, you are spot on my friend

[gs79]

Finally got round to checking out the fork sag on the GS. The full extended fork is 140mm from the top of the dust seal to the underneath of the steering stem. Sitting on the bike on tip toes after bouncing the forks a couple of times the forks move 83mm. If my sums are correct that is a sag of 57mm - which is approximately 40% of the travel. I presume this means I need to add a spacer to bring the sag into the 25 to 30% range is this correct please.

[gs79]

Just checking with you guys, what the correct fork sag figure should be for a Suzuki GS1000E. I have just fitted new progressive springs and the fully extended fork length is 140mm, fork movement when sat on bike and forks bounced is 83mm, giving a sag of 57mm.

[Agemax]

sounds about right to me. does it feel right when you are sat on it?