Progressive Fork Springs - GS1000G Spacer length

[salty_monk]

Have bought a set to fit & just wondered if anyone has already worked out the spacer length required for our model?

I weigh 165lb & have pretty short legs so I don't really want to increase the height too much if possible so I'm thinking to leave fairly soft.

I'm going to use 15wt oil. Should I change the height or stick to the 140mm?

Gonna change the seals at the same time. Rear shocks are in pretty good shape, think TPO must have replaced them at some stage.

Procedure seems simple enough, other than the reversed 5/8 socket on a bar to hold the damper rod any other tips I should know?

Cheers,

Dan

[bwringer]

The Progressive springs will come with a recommendation for spacer length. Since you are of pretty average weight, you'll probably be quite happy with the recommendation.

I weigh, um, let's just say... a helluva lot more than you, so I have to use an ungodly amount of preload to get the correct static sag. With the rider's full weight with gear on the bike and sitting upright and motionless on two wheels, (Put a zip tie on the fork tube to measure, so you only need to balance that way for a moment, then get off and look.) the suspension should be sitting at about 1/4 to 1/3 of total travel. On most GS forks, this comes out to roughly 25-35mm of sag.

Here's one of my spacers with the fork caps installed and ready to begin the titanic struggle to thread them in straight. It takes a LOT of sweat and bad words. For anyone smaller/slower than me, this much preload is not needed.

Yours will be much closer to the top of the fork tube and much easier to deal with.



But here's the happy result -- 25mm static sag with my big butt on it.




15W fork oil is a good starting point, and should make you happy. I mix in 10% Motor Honey to thicken my fork oil, partly to compensate for 80,000 miles of wear, partly because of my mass, and partly because I whip my GS like a rented mule over bad Indiana roads. Works great!

[49er]

Have bought a set to fit & just wondered if anyone has already worked out the spacer length required for our model?

I weigh 165lb & have pretty short legs so I don't really want to increase the height too much if possible so I'm thinking to leave fairly soft.

I'm going to use 15wt oil. Should I change the height or stick to the 140mm?

Gonna change the seals at the same time. Rear shocks are in pretty good shape, think TPO must have replaced them at some stage.

Procedure seems simple enough, other than the reversed 5/8 socket on a bar to hold the damper rod any other tips I should know?

Cheers,

Dan

I am planning this upgrage on my 850 this coming winter. I weigh the same as you Dan. Like Brian, I will probably stiffen the front end damping.
What's this motor honey? Sounds like Dino to me!!
Mine has only 78Ks so shouldn't be too worn yet. Are there any special considerations I need to allow for when running air suspension with the progressive springs mod? Recommended pressure/no pressure?
Brian, that's a pretty flash rule you used to measure the reaction to your baulk.
Cheers
Ian

[bwringer]

I am planning this upgrage on my 850 this coming winter. I weigh the same as you Dan. Like Brian, I will probably stiffen the front end damping.
What's this motor honey? Sounds like Dino to me!!
Mine has only 78Ks so shouldn't be too worn yet. Are there any special considerations I need to allow for when running air suspension with the progressive springs mod? Recommended pressure/no pressure?
Brian, that's a pretty flash rule you used to measure the reaction to your baulk.
Cheers
Ian

Motor Honey is a thick yellowish goop you're supposed to dump into elderly, noisy car engines so they'll run a little quieter, enabling you to sell the car to some unsuspecting victim.

It pretty much looks like honey from bees, and is about as thick. I don't know what they call it on your end of the planet. I think STP engine treatment or any really thick engine treatment is about the same stuff.

In reality, it's pretty useless in car engines (and deadly to motorcycle clutches), but it works great when you want thicker fork oil than you can find on the shelf.

With Progressive springs and proper preload, you don't use any air pressure. That's one good reason for making the switch -- air pressure is dangerously unreliable.

[emjay]

...I weigh, um, let's just say... a helluva lot more than you...

You can't be that heavy, your fingers aren't fat!

[J_C]

I weigh about 215 and need to do the same for mine. I'll probably be doing some research to see if I can find a recommendation on my preload before doing this whole thing, especially if it necesitates lots of sweat! (The bad words are no problem on my end!)

Dan, how are you going to do the ratchet on the rod? If it works I just may have to borrow it from you

[salty_monk]

I got a tip off here for doing the damper rod with picture, reverse a 5/8 spark plug socket after pulling the rubber out (Craftsman type) & use a couple of extensions. This will hold the rod & you can undo as normal. I assume that's what you meant. Other than that I will take it to work & get my neighbour to use his impact driver on it...... Do a search on my name & you'll find the pic a couple of weeks back I think.

Unfortunately the instructions from Progressive don't have a recommendation for the GS1000G - just says measure yourself as per instructions.... Would be much easier if they provided a new top cap with a bolt mounted adjuster washer like my Mountain bike Marzzochi's...

Dan

[bwringer]

IIRC, the standard Prog. recommendations would put the threads on the cap maybe 15-20mm from the threads in the fork leg. In other words, only about 1/2 inch of spacer would be showing above the fork leg. As you thread the fork cap in, it compresses a bit more. It's pretty easy to get them started if you only have to compress them a little bit.

That might be a good place to start, anyway. Give it a try, measure static sag several times to get an average (stiction makes static sag somewhat variable), test ride a few times, sleep on it, think about it some more, then try making different spacers. Tubing and hacksaw blades are cheap. Clean up the spacers with a big file or grinder to make sure they're EXACTLY the same length.

[salty_monk]

So nobody with a 1000 (preferably a G) done this before? I was just looking for a starting point....

BWRINGER can you PM me your weight & spacer length, should give me an idea. I can understand if you don't want it on here, no need to be shy though

Cheers,

Dan

[bwringer]

My precision eyeball-engineered spacers are 86.25mm long. I did carefully grind them to be the same length.



With gear (including crappy rain gear over armor), I weigh something like 270 pounds, and I am a rather aggressive rider:


Large and in charge!

Your size and riding style are likely different -- the above spacer length was my third try, and I rode for a couple of weeks or months in different situations to test each variation of fork oil mix and spacer length.

[SqDancerLynn1]

[IMG]file:///C:/My%20Documents/scan.jpg[/IMG]

well crap!!!

[salty_monk]

Nice picture BWRINGER, I'm working on being able to ride like that!

I'll have a play with the forks, TomMLC didn't use any spacer in his 1,000 so if I get them apart & no spacer looks somewhere close I'll give that a go. Should be easy enough to add some in at a later date if necessary.

Dan