Squeaky front forks

[danny01975]

82 gs 1100 GK. Just replaced the stock front springs with progressive springs. All went well and no issues.

The new ones are much better than the old ones. No more diving! However, now when I compress the front suspension it squeaks.

Of note.. I didn’t have access to fork oil at my local auto parts store but the service manual says to use #15 fork oil OR 1:1 10-W30:ATF. Which is what I used. The service manual also called for 255 ml of fluid. Which is a little less than what I drained out.

that would be the only deviation from the manual. If you want to call it that.

Any ideas?

 

[Brendan W]

The specified volume is really a guide.
There may not be much of a difference but you would have to consider the possibility that the new springs take up a different amount of space than the old.
Could the squeaking be dry sliding between the fork legs and the seals?
I have used a tiny amount of silicone grease on there to eliminate a squeak on my R1100R.
I used 2:1 10W40 and ATF with no issues on my 850. The thinner oil has a disproportionate effect on the viscosity of the brew.

 

[danny01975]

Could the squeaking be dry sliding between the fork legs and the seals?

Could be dry sliding. Weird that it would start now but it’s possible. Will check that out.

Also good to know you didn’t have any issues with the oil/ATF blend. I’d never seen that before I read it in the manual.

 

[Grimly]

Also good to know you didn’t have any issues with the oil/ATF blend. I’d never seen that before I read it in the manual.

Thank your luck the original factory oil was long gone. The factory used fish oil, which stunk to high heaven when drained after a few years use.

 

[danny01975]

I tried lubing the forks around the seals but it's still the same. I think it's something internal squeaking. Maybe the damper rod?? I ordered some actual 15wt fork oil. I'll try swapping out my ATF blend for regular fork oil. Maybe the 1:1 just isn't the right viscosity or lubricity. If that doesn't work I'l either have to rebuild them, or just ignore it!

 

[Cipher]

82 gs 1100 GK. Just replaced the stock front springs with progressive springs. All went well and no issues.

The new ones are much better than the old ones. No more diving! However, now when I compress the front suspension it squeaks.

Of note.. I didn’t have access to fork oil at my local auto parts store but the service manual says to use #15 fork oil OR 1:1 10-W30:ATF. Which is what I used. The service manual also called for 255 ml of fluid. Which is a little less than what I drained out.

that would be the only deviation from the manual. If you want to call it that.

Any ideas?

The extra was likely moisture. Was the oil grey?
I've used the Suzuki recipe. Its far better than old oil.

 

[Grimly]

Very odd, the parts which are moving relative to each other are covered in oil.

 

[Brendan W]

Time for the Mk.1 Earhole.
Get someone to sit on the bike and compress the front and see if you can pinpoint exactly where it's coming from.
Small dogs are good at this, Humans can use a funnel as an ear trumpet.
What is moving, speedo cable, brake hose. Is the fairing moving on a mount.
Is it different if you chock the front wheel to compress instead of holding the brake on.

 

[danny01975]

The extra was likely moisture. Was the oil grey?
I've used the Suzuki recipe. Its far better than old oil.

The oil was black black!

 

[danny01975]

Time for the Mk.1 Earhole.
Get someone to sit on the bike and compress the front and see if you can pinpoint exactly where it's coming from.
Small dogs are good at this, Humans can use a funnel as an ear trumpet.
What is moving, speedo cable, brake hose. Is the fairing moving on a mount.
Is it different if you chock the front wheel to compress instead of holding the brake on.

Im nearly certain it's the right fork. But good idea. I'll get someone to put their ear next to it to be sure, then use the stethoscope.

 

[salty_monk]

Which way up did you put the springs? What did you use for a preload spacer inside the fork? If you're not careful the spring can move off centre & run against the inside of the leg as it compresses, that causes the noise.

 

[danny01975]

Which way up did you put the springs? What did you use for a preload spacer inside the fork? If you're not careful the spring can move off centre & run against the inside of the leg as it compresses, that causes the noise.

I put the springs in with the shorter coils up. But I've read that it doesn't matter. Progressive also says it doesn't matter. I cut down the factory preload spacer to 1.75" per the progressive specs and re-installed it.

Now that you mention it, there's a small retainer / washer that goes between the top of the spring and the preload spacer. I do think I may have installed that upside down, with the protrusion going up, into the preload spacer. But the diagram shows it oriented downward. That makes sense if it's supposed to keep the springs centered, away from the inside of the fork tube.

You may have just solved it! Will work on it this weekend an report back!

 

[oldGSfan]

Thank your luck the original factory oil was long gone. The factory used fish oil, which stunk to high heaven when drained after a few years use.

Hoo yah. Strangely I just swapped fork springs on a '23 Ducati DesertX and wow did it stink. Maybe some bad olive oil!

The fish oil comment made me think of Clockwork Orange's humble narrator... “How art thou, thou globby bottle of cheap stinking chip-oil?

I really have nothing meaningful to add, but am looking forward to the findings. Oh. a mechanic's stethoscope is handy for narrowing down the exact area of the noise. That may be meaningful.

 

[salty_monk]

I put the springs in with the shorter coils up. But I've read that it doesn't matter. Progressive also says it doesn't matter. I cut down the factory preload spacer to 1.75" per the progressive specs and re-installed it.

Now that you mention it, there's a small retainer / washer that goes between the top of the spring and the preload spacer. I do think I may have installed that upside down, with the protrusion going up, into the preload spacer. But the diagram shows it oriented downward. That makes sense if it's supposed to keep the springs centered, away from the inside of the fork tube.

You may have just solved it! Will work on it this weekend an report back!

Yes spring direction is not important for operation but sometimes it can make a difference to the noises the fork makes. I've done a fair amount of messing around with springs, stock ones, cut down ones (makes them stiffer if you fit more solid spacer to take up what you cut off), progressive brand, progressive with the close wound cut off to make a straight weight, straight weight, mixing two different spring weights inside the same fork leg, adding cartridge emulators etc.

Schedule 40 with a metal fender washer at each end makes a good spacer BTW if you ever need extra length.

Yes that spacer is meant to fit inside the top coil of the spring.