Why I dread changing fork oil

[Hoomgar]

The scary part is I understood all of that and it makes perfect sense to me :shock:

Thanks Brian, now you have given me even more things to "over-think" about :lol:

I'll be using this info.

 

[Sandy]

I use the zip tie method all the time. It really takes the guess work out of suspension tuning. I find, however, I get a better visual reference by using one on each fork leg, one set where the suspense would actually bottom out and one to use to measure suspension travel. Hoomie, on my naked GS1000 with progressive springs I've found that a 5/8" inch preload spacer, 15W fork oil and no air works great for me at 210lbs. I've got 1 1/4" preload and come to about 1" of bottoming out under very hard braking. This setup works good for me and performs well for what I would call moderately aggressive riding on rough roads, what ever that means! Maybe use this as it start point for your setup.

 

[Hoomgar]

I use the zip tie method all the time. It really takes the guess work out of suspension tuning. I find, however, I get a better visual reference by using one on each fork leg, one set where the suspense would actually bottom out and one to use to measure suspension travel. Hoomie, on my naked GS1000 with progressive springs I've found that a 5/8" inch preload spacer, 15W fork oil and no air works great for me at 210lbs. I've got 1 1/4" preload and come to about 1" of bottoming out under very hard braking. This setup works good for me and performs well for what I would call moderately aggressive riding on rough roads, what ever that means! Maybe use this as it start point for your setup.

Thanks Sandy. I'm working on an 83 1100 though but the same school of thought applies. Where have you been hiding my friend!?

 

[Billyboy]

I use the zip tie method all the time. It really takes the guess work out of suspension tuning. I find, however, I get a better visual reference by using one on each fork leg, one set where the suspense would actually bottom out and one to use to measure suspension travel. Hoomie, on my naked GS1000 with progressive springs I've found that a 5/8" inch preload spacer, 15W fork oil and no air works great for me at 210lbs. I've got 1 1/4" preload and come to about 1" of bottoming out under very hard braking. This setup works good for me and performs well for what I would call moderately aggressive riding on rough roads, what ever that means! Maybe use this as it start point for your setup.

Thanks for the info Sandy! It turns out that I ordered progressive springs in MAY and they just got in. I guess I forgot I ordered them. I've also ordered fork seals, and euro bars from Bikemaster. I'll be doing it all in one shot when the stuff gets in.

I got ten pounds on you and like to use the springs, so I might use a 3/4 " spacer.

Is there a thread on replacing seals?

 

[Sandy]

Thanks Sandy. I'm working on an 83 1100 though but the same school of thought applies. Where have you been hiding my friend!?

Been hiding just about everywhere but home Mark. Family reunion and a trip to Vancouver Island took up about 12 days, back to work for 4 days, then off to a another reunion my wife arranged with her retired nursing buddies, bush camped for 5 days and had a big lightning storm/wind storm and had to cut our way out of our campsite. People nearby had their car totalled with some trees that came down and luckly nobody was hurt. Life never gets dull. Thanks for asking though. Maybe I'll be around a little more now. Maybe I'll even get to ride my GS a bit.

 

[Billy Ricks]

One thing to keep in mind is if once you get preload set to the desired amount of sag for your weight, if you bottom out you need stiffer springs. More preload at that point isn't the right way to go.

 

[8trackmind]

I got ten pounds on you and like to use the springs, so I might use a 3/4 " spacer.

Depending on your progress with the wheelies, you may need an even larger spacer. :|

 

[Billyboy]

Depending on your progress with the wheelies, you may need an even larger spacer. :|

Yeah, good point. Hmmm. And my Euro bars just shipped. That'll put more weight up front. I may need to start with a full inch and experiment until I stop slappin the tank.

 

[bwringer]

One thing to keep in mind is if once you get preload set to the desired amount of sag for your weight, if you bottom out you need stiffer springs. More preload at that point isn't the right way to go.

True, but where are you going to find a selection of spring rates to fit skinny old GS forks? AFAIK, they simply aren't available. Maybe there's someone that makes fork springs for vintage racers or something.

At least with progressive-rate springs, the spring rate does go up as the spring is compressed. So with more preload, you do use a higher spring rate. The problem is, the whole process is pretty imprecise and choices are severely limited by the availability of different fork springs.

With that said, upgrading to Progressive brand fork springs and shocks, along with taking some care in setting sag is about the biggest performance bang for the buck possible. (Progressive brand stuff is the least expensive suspension upgrades option, and is plenty good for most GS riders.)

As many have remarked, just getting the suspension in the ballpark transforms a GS. An old rattly antique suddenly handles surprisingly well. Even if you're not a corner carver, the improved feel, precision, safety, and comfort are amazing and well worth a couple hundred bucks and an afternoon in the garage. A skilled rider can keep up with modern bikes all day -- the bike stops being an obstacle.

Of course, there are intrinsic limitations to those skinny forks, flexible frames, and heavy engines. The laws of physics still apply, but decent suspension can help you bend the rules a bit...

 

[Billy Ricks]

Either using springs from a heavier bike or calling suppliers will yield heavier than stock springs. As long as they aren't too long for the forks they can be adapted with preload spacers.