Spacer required?

[Guest]

1981 GS750E

So, I tore my forks down for a much needed seal job. Black oil of course, thought they had never been done. I haven't rode this bike in quite a while and it's down to the frame at the moment for a restomod.

First issue was that the seals were upside down according to basscliff's site(spring band up). So now I'm guessing that may be the reason for the leak, but I'm glad I found it now.

Next issue I'm not sure on is that it seems the spacers on top of the spring are gone. Are these required? Will it destroy anything to run without them?

Lastly, the dampener rod bolt is rounded, but that is my problem and I will deal with that after I get parts.

[bwringer]

Some aftermarket springs on some bikes don't require spacers. No idea what the situation might be on your bike.

If it had spacers and you lost them, then you'll need to make new spacers with PVC pipe. A good approximate place to start would be to cut spacers so that the spring is compressed (preloaded) about 3/4 to 1 inch (19-25mm) with the fork caps installed. Measure sag and fine-tune from there.

If they're the stock springs, they're most likely hopelessly soft anyway, so you might be best off to just replace the springs with Sonic springs. (Preload with the correct spring rate in place for your weight and riding style will be about 3/4".) Use the calculator to find the correct spring rate: http://www.sonicsprings.com

If it never had spacers, well, some bikes and some aftermarket springs didn't use them.

[Steve]

Brian, I think he might be talking about the spacer/washer that some bikes have above the fork seal, just below the retainer.

Could be either #6 or #8 in this diagram:


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[78550GS]

I was going by basscliff's seal replacement write up that I now realize is for an 850, so differs a bit.

By the diagram above, I am missing #25 and #26. I don't believe it has aftermarket springs, I think #25 was just removed to (incorrectly) lower the front end.

[bwringer]

Thanks for the clarifications! #26 is just a washer, so you should be able to scare up any washer that will sit on top of the fork spring and fit inside the fork leg.

If #25 (the "secondary" spring) is missing, just replace it with a washer and PVC pipe spacer to give a base amount of preload as I mentioned above. Once it's assembled, you'll need to take some measurements to see whether the resulting spring rate is acceptable. Ideally, you want to end up with about 1 to 1.25 inch of static sag (I'll leave it up to you to Google static sag forks to learn more about this...).

[Steve]

Just to give you another idea on how long to make those PVC spacers, remove the cap on top of the tube, install a washer that will fit on top of the existing spring, then, with the forks fully-extended, measure from the top face of that washer to the top of the fork tube. Use that as your starting length for the PVC spacer. You will have to push down on the spring a bit to screw the fork cap back on, that is your "preload".

HINT: before installing the spacer, thread the cap on just a couple of turns. Slowly unscrew it WHILE PULLING UP ON IT. Note where the threads finally "let go", mark it somehow. I use a Sharpie for this. Now install the spacer, but this time, you will know exactly where the threads will start grabbing, so line up your mark accordingly.

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[78550GS]

Thanks guys!

GSR is always an invaluable resource for me.