fork oil sources/brands/compatibility?

I just received my Sonic Springs in the mail with the liter of oil recommended by Rich. He did the install for me on my DL650 a few years ago... I will do this one (ST1300) myself.

If, for any reason, I need more oil than the liter he included in the package (spillage, stupidity, just need more, whatever)... where do you buy that stuff? I am given the impression that from one brand to another the "weight" specs are not consistent.. is there a cross-reference or conversion table somewhere with different brands?

looking for advice here.

I envision needing a tad more oil while the bike is apart and having to send off for another quart and waiting a week. would rather have that 2nd quart on hand just in case.

thanks -

This is a pretty good reference point:

http://www.peterverdonedesigns.com/lowspeed.htm

You shouldn't be short much more than an ounce per leg. Fill the gap with some decent automatic transmission fluid and your seals will thank you. If it's more than an ounce, well, then you probably just spilled too much.. :

fabulous bkra13. I have plenty of AT fluid on hand. excellent. appreciate it mucho - KS.

++ on the trans fluid , thats all they used to use before they come out with all the fancy fork oils ! I believe most trans fluid is about 10w if memory serves me right or not ! LOL . Good luck !

MIKE

Would you be happy with a $13,000 motorcycle that you spent $100 on aftermarket springs for then stick ATF in the forks instead of bespoke fork oil?

Would you prefer Dextron, Mercon, or 7176, or ATF 4+?

dduelin said:

Would you be happy with a $13,000 motorcycle that you spent $100 on aftermarket springs for then stick ATF in the forks instead of bespoke fork oil?

Would you prefer Dextron, Mercon, or 7176, or ATF 4+?

Click to expand...

I would be more than happy to put LESS THAN AN OUNCE of ATF fluid in my $13k motorcycle with $100 springs. Yes.

No worries guys. A smidge of ATF won't hurt anything.

And you are correct in stating that fluid weights of fork oils are not consistent across the board. Unlike motor oil, there isn't a set standard for viscosities. One companies 7.5wt is anothers 5wt and another's 10wt. If you put ATF in one fork leg, I would put a similar amount in the other fork leg. ATF won't have the same properties as whatever weight fork oil you are using and you want both legs to be suspended/dampened equally.

I recently installed Race Tech springs in my ST1300. Had a liter of Hyperpro fluid left over from a previous suspension change (on a different bike). The one liter was just about perfect for my application.

Not too late Iride. Thanks.

Now the last post by iride is interesting. I agree with previous posts...if you buy "Fork Oil", why change the character of the fork oil by adding ATF??? The idea of adding ATF sealer sparked interest because I realy dislike changing fork seals. One would think that Fork Oil in this day & age contains additives that promote seal life, in fact the Peter Verdone site says "Almost all suspension oils will contain viscosity modifiers, seal conditioners, and anti-foam agents". The key word is "Almost".

Since I am about to buy Sonic Springs I should ask the question:
1. Did ksievers need more oil than the 1 liter?
2. Does the Sonic oil actually say it contains seal conditioners?
Thanks for the advice guys. Greg

I'll throw a little different info in here for you. Consider the actual uses for these fluids. Fork oil is essentially a hydraulic fluid. It deals with compression forces and lubrication of sliding parts. On the other hand, ATF has friction modifiers in it to INCREASE friction, since a super slick fluid is not what you want with wet clutches and bands. Will a small amount hurt? Probably not. Would I completely fill my forks with it? NO WAY. Sure, it may have been used back in the day...you know, back before technology brought us fluids that work better, and back when putting 20k miles on a motorcycle in a lifetime was a lot.

If you want a substitute, I'd rather use regular hydraulic fluid. It doesn't have friction modifiers, and is designed for applications where its under pressure, and has to lubricate sliding parts. Hmmmm, sound a lot like forks?

bkra13 said:

You shouldn't be short much more than an ounce per leg. Fill the gap with some decent automatic transmission fluid and your seals will thank you. If it's more than an ounce, well, then you probably just spilled too much.. :

Click to expand...

I realize this is an old thread, but I was wondering - if I need to "stretch" the fork oil a bit - why not use a little MMO (equal amounts in each fork) ? .