'83 GS850GL - Seals leaking -- FIXED Now ;)

[Wingsconsin]

A few years ago I re-did my forks completely (or so I thought)
I took them apart carefully following the tutorial on this site -
I added NEW SONIC springs ; and new seals, and dust covers -
But during that rebuild I made a few mistakes (I learned over the next few months/years); that I didn't realize as this was my first ever fork rebuild --

Mistake #1 - I did not replace the slider bushings inside the forks I thought they would be fine as the bike only had 20-30K miles on it -WRONG - After a few years I noticed the forks were 'sticking' in the up or down position - a combination of leaked oil and bad sliders was causing the 'stiction' I think - cheap enough -- DO it !

Mistake #2 - I installed the fork seals upside down (I know - dumb but I did it:culpability:) This effectively caused the seals to leak a tiny bit every time they went up or down - eventually I was low on fork oil although it wasn't running down the fork exterior - I drained about 400ml of old fork oil (the correct amount should be 502 ml) -- AND this stuff was smelly; grey messy, bad oil.

Mistake #3 - This one is opinion and not sure if it made a big difference BUT - I reassembled the forks after setting the fork seal - I think by doing this you hurt the seal by sliding the tube in through the seal - This time I added the seal LAST and used the Motion Pro seal driver to seat it fully. Time will tell if this is a better process but I feel like it will be most beneficial :uncomfortableness:

Mistake #4 - Added too much 'pre-load' If 3/4" is enough then 1-1/4" is better -- right ?
NOPE -- Harsh bumpy bouncing ride before - I redid the pre-load spacer to the correct length based on my new weight (lost 80# last year) and things seem better. :shame:SO - My suspension is now freshly rebuilt front forks completely with Sonic springs and New Hagons rear shocks designed for me by Dave Quinn (retired now) - That bike is a hoot to ride nownthego:

 

[Dogma]

Good suspension is a wonderful thing, innit?

#1: For those in the audience, sticky forks can also be the result of slightly bent forks. Mine are each curved about a millimeter, maybe 1.5 (not a localized bend). Lucky for me, they have the exact same deviation, and can be aligned so they work properly. How much warp is too much is a judgement call. I wouldn't trust a fork with a distinct kink.

#3: You can do the seals first, but you have to be careful when inserting the fork leg through the seal. Make sure the taper on the end of the folk leg gets through the seal without pulling the lip in, and make sure no sharp edges of any kind run over the seal's lip. If you have the tool, it's probably safest to do it the way you did.

#4: Did you have some equation for calculating preload from your weight, or did you set it according to static sag as a percentage of full travel? I can't remember the correct percentage, or I'd quote it at you. Whatever, I'm sure your Sonic Springs came with correct instructions, and you followed them diligently.

 

[Steve]

Did you have some equation for calculating preload from your weight, or did you set it according to static sag as a percentage of full travel? I can't remember the correct percentage, or I'd quote it at you.

If I remember correctly, sag should be about 15-20% of available travel.

For forks with about 6 inches of travel, sag should be 1 to 1 1/4 inches.

On the forks that I have set up for our bikes, I put the length of PVC tubing on top of the fork spring in the fully-extended fork, then cut the PVC at the top edge of the fork tube. When the cap is installed, it compresses the spring enough to have the preload pretty darn close. :encouragement:

.

 

[Brendan W]

Wow! Congratulations on the 80#
I'll get around to reading that fork stuff eventually

 

[Wingsconsin]

Wow! Congratulations on the 80#
I'll get around to reading that fork stuff eventually

Thank you - I would like to take off another 20# but these last ones are fighting back

If I remember correctly, sag should be about 15-20% of available travel.

For forks with about 6 inches of travel, sag should be 1 to 1 1/4 inches.

On the forks that I have set up for our bikes, I put the length of PVC tubing on top of the fork spring in the fully-extended fork, then cut the PVC at the top edge of the fork tube. When the cap is installed, it compresses the spring enough to have the preload pretty darn close. :encouragement:

.

Your method of 'measuring' is pretty close to where I ended up after some calculations and some WAG (wild a$$ guess) process

Good suspension is a wonderful thing, innit?

#1: For those in the audience, sticky forks can also be the result of slightly bent forks. Mine are each curved about a millimeter, maybe 1.5 (not a localized bend). Lucky for me, they have the exact same deviation, and can be aligned so they work properly. How much warp is too much is a judgement call. I wouldn't trust a fork with a distinct kink.

#3: You can do the seals first, but you have to be careful when inserting the fork leg through the seal. Make sure the taper on the end of the folk leg gets through the seal without pulling the lip in, and make sure no sharp edges of any kind run over the seal's lip. If you have the tool, it's probably safest to do it the way you did.

#4: Did you have some equation for calculating preload from your weight, or did you set it according to static sag as a percentage of full travel? I can't remember the correct percentage, or I'd quote it at you. Whatever, I'm sure your Sonic Springs came with correct instructions, and you followed them diligently.

#3 - I have the motion pro fork seal driver and would be willing to loan it out to anyone for the cost of shipping - I also have the one for the Goldwing GL1800 which is considerably larger (45mm) - These things work well in my opinion

#4 - The Sonic Springs DID come with some instruction - which I followed nearly to the letter - until I made my own 'adjustment' to the pre-load by adding a little bit more length to the spacer (of course I knew better -- right?)
Tragedy struck and someone in my garage threw those instructions in the trash -- so being able to re-calculate was not really a best practice option for me
However I DID find in my storage box the first set of spacers I made which seemed to be the ones that I followed the directions on ; and I used them this time.
I can not speak to whether the suspension is optimum at this time -- but I can assure you it is a lot better than it was before