Fork Oil

[GateKeeper]

OK, so I was at the local store today and they had on clearance fork oil, but I was not sure which one to get, so I am here to ask for some guidance on which one to get.

It was PJ1 fork oil, one was a 10wt and the other is a 20wt, one is lighter and one is heavier

so on my 1983 GS750E, what is the one to use, I do have the air option as well, not sure if that makes a difference

and will one bottle be enough ?

Thanks

 

[tom203]

I like 15 weight myself! buy one pint of each and make up your own blend. Do you know what you have now? Anyways, one quart is a lot of fork oil.

 

[GateKeeper]

right now I have nothing in the forks, bike is in rebuild mode and everything has been drained, have to add oil latter and put forks back on the bike, there were no leaks so I did not do a full rebuild of the forks, I saw no need.

so it's personal preference ? lighter makes the forks easier to compress, heavier makes it harder to compress ? I am guessing

 

[Steve]

so it's personal preference ? lighter makes the forks easier to compress, heavier makes it harder to compress ? I am guessing

Not so much "easier" or "harder", but "how quickly".

The lighter oil will not be as harsh as the heavier oil. Most here will use 10w or 15w, not too many will use 20w.

Personally, I follow the suggestions of a race mechanic that I read about: "use the lightest oil that will do the job".
The "job" here is to damp the movement of the suspension to keep the front wheel on the gound as much as possible.

I use 10w in all the bikes in my garage. One quart should be plenty.

.

 

[BassCliff]

Hi,

I tried 15wt fork oil in my bike and found it too harsh. I went back to 10wt. Check the manual for the amount of oil used in your forks. Mine uses 251ml, a little less than 8.5 fluid ounces (US). A quart will be enough for your forks with plenty left over. Just as important as the amount will be the level of fork oil in each fork. They need to be exactly the same, within 1mm, usually 140mm below the top of the fork tube, fully compressed, without the springs.

You'll find more information on my little website.

Thank you for your indulgence,

BassCliff

 

[1_v8_merc]

I used 15w40.

Absolutely love it on smooth pavement.
But if you hit any noticable bumps, it feels like a jackhammer.

I'm definitely going 10 next time.

BTW, fork oil is made by simply mixing Motoroil and ATF.
(not sure if anyone mentioned that yet...)

 

[SVSooke]

I like 15wt,that's what's in Yellers forks.If in doubt do the 10wt,the 20 would be to harsh IMO.

 

[7981GS]

I use 10W in the bikes with stiffer after market springs and 15W in the one with stock springs and spacer.

Daniel

 

[chuck hahn]

I use the service manual recipe of 50/50 mix of oil and ATF. With 6 bikes its way cheaper to make it.

 

[GateKeeper]

Thanks for the input.....

the mix of motor oil and ATF is a good idea as well, or the pre made stuff, either way I have to buy to mix my own or the finished product

 

[BassCliff]

Hi Mr. GateKeeper,

Sorry, I had to edit my earlier post. When measuring the fork oil level, do this without the springs, the tubes fully compressed. There's a couple of guides with pictures on my little website.


Thank you for your indulgence,

BassCliff

 

[GateKeeper]

Thanks BasCliff

I am just painting the bottoms, and then I will be ready to put them back together, and back on the bike.

 

[Guest]

I use the 30wt fork oil in my forks, never found it to be harsh though like the way it keeps the front end from diving under hard braking. I do like a stiff front end lol.